Journal Sciences News
The Journal of Pain
July 2018
Impact of the formulation of biosourced phenolic foams on their fire properties
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): C. Delgado-S
July 2018
Determination of the long-term performance of district heating pipes through accelerated ageing
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Alberto Vega, Nazdaneh Yarahmadi, Ignacy Jakubowicz The lifetime of pre-insulated district heating pipes (DHPs) is commonly evaluated using the method described in the normative European Standard EN 253. This lifetime is normally calculated using an Arrhenius equation, which makes use of test results from accelerated ageing tests at elevated temperatures. In this investigation, long-term accelerated ageing tests of DHPs at elevated temperatures were carried out. The ageing behaviour, especially at the interface between steel pipe and polyurethane (PUR) foam, showed several routes of degradation. It is clearly demonstrated using measurements of shear strength, thermal conductivity and alterations of chemical structure by Fourier Transform Infrared spectroscopy that the results of accelerated ageing at 170 and 150
July 2018
Comparative study of the photochemical stability of HDPE/Ag composites
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Ifigenia Grigoriadou, Eleni Pavlidou, Kostas M. Paraskevopoulos, Zoi Terzopoulou, Dimitrios N. Bikiaris In the present study, HDPE composites containing different concentrations of silver (Ag) nanoparticles (0.5%, 1%, 2%, 3%, and 5
July 2018
Stabilization of recombinant spider silk in thermo-oxidative degradation: High-throughput screening for antioxidants
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Anh T.N. Dao, Jun'ichi Shimokata, Kengo Takeuchi, Koyuru Nakayama, Toshiaki Taniike Recombinant spider silk has arisen as one of the most promising nature-derived building blocks owing to its extraordinary mechanical properties, while its instability against thermo-oxidative degradation becomes a major drawback toward industrial applications. Here, we have firstly implemented a high-throughput screening of antioxidants on the stabilization of recombinant spider silk at an elevated temperature. The usage of high-throughput chemiluminescence imaging has allowed us to screen antioxidants with a wide spectrum of molecular structures and quickly provided two good candidates to stabilize recombinant spider silk powder through an impregnation process: E310 and BHT. An accelerated aging has further proven that these antioxidants suppressed the thermo-oxidation of recombinant spider silk through scavenging the formed radical species and slowed down the formation of carbonyl groups as oxidation products. In addition, we have employed a solution mixing process to further improve the stabilization efficacy of the antioxidants and this method also extended our selection on effective antioxidants, including vitamin E, AO-30, AO-40, HP-10, and especially Irganox 1098. These screening results provide guidelines of selecting or even developing potential antioxidants for stabilizing protein materials.

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July 2018
Combined effects of Sepiolite and Cloisite 30B on morphology and properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/polylactide blends
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Idris Zembouai, Mustapha Kaci, Lynda Zaidi, St
July 2018
Novel biocompatible PBS-based random copolymers containing PEG-like sequences for biomedical applications: From drug delivery to tissue engineering
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Martina Fabbri, Giulia Guidotti, Michelina Soccio, Nadia Lotti, Marco Govoni, Emanuele Giordano, Massimo Gazzano, Rita Gamberini, Bianca Rimini, Andrea Munari A series of random poly(butylene succinate)-based copolymers, (poly(butylene/triethylene succinate) (P(BSmTESn)), containing ether-oxygen atoms were successfully synthesized by melt polycondensation of succinic acid and 1,4-butanediol in the presence of triethylene glycol (TEG) (TEG content up to 40
July 2018
Characterization of the chemical structure of vinyl ester resin in a climate chamber under different conditions of degradation
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Cristina Alia, Jos
July 2018
Flame retardancy of microcellular poly(lactic acid) foams prepared by supercritical CO2-assisted extrusion
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): D
July 2018
On the degradation properties of electrospun fibers based on PLLA: The effect of a drug model modification
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): Matteo Eleuteri, Laura Pastorino, Orietta Monticelli In this work, the features of electrospun fibers based on poly(l-lactide) (PLLA) containing drug model molecules, which were modified as to render them more dispersible in the polymer matrix and potentially capable of tuning the PLLA degradation, were investigated. Indeed, the above compounds, constituted by a pyrene terminal group attached to a short chain of poly(d-lactide) (Pyr-D) or PLLA (Pyr-L), were synthesized by employing 1-pyremethanol (Pyr-OH), a widely applied hydrophobic model drug, as the initiator of the ring opening polymerization (ROP) of L- or d-lactide. 1H NMR measurements allowed to calculate the oligomer molecular masses, which resulted to be in satisfactory agreement with the theoretical value. With the aim at verifying the influence of the synthesized compounds on the material final properties, electrospun fibers characterized by different compositions were prepared, that is fibers based on neat PLLA, PLLA with Pyr-OH, PLLA with Pyr-L, PLLA with Pyr-D and PLLA with Pyr-OH and Pyr-D, by adding an amounts of the various additives in order to obtain the same pyrene content. The morphological characterization, accomplished by means of FE-SEM, evidenced that the addition of the above compounds did not significantly influence the morphology of the fibers. Conversely, the fluorescent microscopy measurements demonstrated a different dispersion of the pyrene-based additives in the various samples, namely an aggregation of Pyr-OH and a homogeneous distribution of Pyr-L as well as Pyr-D. The fiber thermal properties were investigated by DSC measurements. In general, the annealing treatment, accomplished at 80
June 2018
Effects of chain-extending stabilizer on bioplastic poly(lactic acid)/polyamide blends compatibilized by reactive extrusion
Publication date: July 2018
Source:Polymer Degradation and Stability, Volume 153 Author(s): JeongIn Gug, James Soule, Bin Tan, Margaret J. Sobkowicz The immiscible bio-plastic blend of poly(lactic acid) (PLA) and polyamide11 (PA11 or Nylon11) was compatibilized, using a catalyzed the ester-amide interchange chemical reaction during reactive extrusion. The effects of screw configuration on mixing and reaction optimization were explored. It was found that effective mixing and minimized degradation were achieved when kneading elements were installed only near the die end of the extruder rather than near the beginning of the melt section. However, significant degradation of PLA could not be avoided during processing, which led to a decrease in mechanical strength of blend. To prevent the molecular weight reduction, tris(nonylphenyl) phosphite (TNPP) stabilizer was introduced to improve the thermal stability of PLA matrix. Improvement to both tensile strength and elongation were achieved in the resulting PLA/PA11/TsOH/TNPP blend.
June 2018
Layer-by-layer assembly of efficient flame retardant coatings based on high aspect ratio graphene oxide and chitosan capable of preventing ignition of PU foam
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Lorenza Maddalena, Federico Carosio, Julio Gomez, Guido Saracco, Alberto Fina The layer-by-layer (LbL) technique is adopted for the construction of multilayers encompassing chitosan and graphene oxide (GO) platelets capable of improving the flame retardant properties open cell PU foams. The LbL assembly follows a linear growth regime as evaluated by infrared spectroscopy and yields a multilayer structure where GO platelets are embedded within a chitosan continuous matrix. 3 and 6 bi-layers (BL) can efficiently coat the complex 3D structure of the foam and substantially improve its flame retardant properties. 3BL only add 10% to the original mass and can suppress the melt dripping during flammability and reduce both the peak of heat release rate by 54% and the total smoke released by 59% in forced combustion tests. Unprecedented among other LbL assemblies employed for FR purposes, the deposition 6BL is capable of slowing down the release of combustible volatile to the limits of non-ignitability thus preventing ignition in half of the specimens during cone calorimetry tests. This has been ascribed to the formation of a protective coating where the thermally stable char produced by chitosan serves as a continuous matrix embedding GO platelets, which control volatile release while mechanically sustaining the PU foam structure.
June 2018
Towards understanding the breakdown and mechanisms of glass fiber reinforced polyester composites in sub-critical water using some of the most employed and efficient additives from literature
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): H
June 2018
Growth associated degradation of aliphatic-aromatic copolyesters by Cryptococcus sp. MTCC 5455
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Mayilvahanan Aarthy, Puhazhendi Puhazhselvan, Ramchary Aparna, Antony Sebastian George, Marichetti Kuppuswami Gowthaman, Niraikulam Ayyadurai, Kazuo Masaki, Toshiaki Nakajima-Kambe, Numbi Ramudu Kamini The degradation of aliphatic-aromatic copolyesters, poly[(butylene succinate/terephthalate/isophthalate)-co-(lactate)] (PBSTIL) and poly(butylene adipate co-terephthalate) (PBAT) under mesophilic conditions was investigated using the yeast, Cryptococcus sp. MTCC 5455. Complete degradation of PBSTIL and PBAT films was observed at 25
June 2018
Rheological properties, oxidative and thermal stability, and potential application of biopolyols prepared via two-step process from crude glycerol
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Aleksander Hejna, Paulina Kosmela, Marek Klein, Kamila Gosz, Krzysztof Formela, J
June 2018
Halloysite nanotubes and thymol as photo protectors of biobased polyamide 11
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Giuliana Gorrasi, Valeria Bugatti, Martina Ussia, Raniero Mendichi, Daniela Zampino, Concetto Puglisi, Sabrina Carola Carroccio The formulation of cost-effectiveness sustainable materials is extensively growing and becoming an attractive approach for both industrial and academic fields. In this context, the bio-based aliphatic polyamide 11 (PA11) has acquired significant interest as environmentally friendly thermoplastic option. In addition, its formulation with selected natural antioxidant and/or reinforced compounds through green processing methods, might improve physical and mechanical properties without sacrificing the intrinsic bio-based nature of the matrix. In this work, we have investigated and compared the photo-oxidative degradation processes occurring on PA11 composites based on thymol and halloysite nanotubes prepared by using ball-milling method. In particular, halloysite nanotubes were used as green nano-container of a natural antioxidant molecule, and reinforced nano-filler as well. Molecular and structural information of photo-exposed samples were obtained by using size exclusion chromatography (SEC) and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Thermal and mechanical properties were also tested as well as thymol release. Data collected confirmed that PA11 filled with HNTs-Thymol nano-hybrid showed superior durability performance if compared to both pure PA11 and PA11 blend realized by simply adding thymol and HNTs to polymer matrix. Furthermore, we found that HNTs and thymol combined in the nano-hydrid form exhibited an active and synergic role to achieve a major photo stabilization of PA11 biocomposite, without sacrificing its mechanical properties.
June 2018
Reactive compatibilization and melt compounding with nanosilicates of post-consumer flexible plastic packagings
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): E. Garofalo, L. Di Maio, P. Scarfato, F. Di Gregorio, L. Incarnato Flexible plastic packagings are rapidly gaining market share since they offer significant functional benefits. However, they also pose a challenge from a recycling perspective. In fact, due to the presence of different polymeric fractions and to contamination by organic substances and out-of-target materials, such as paper and metals, the mechanical properties of the recycled material are relatively poor. Addition of nanoparticles to plastic waste can offer the combinations of improved properties and processing, and reduce operational cost. Moreover, in recent studies it was demonstrated that they can also act as blend compatibilizers. The aim of this study is the upgrading of Fil-s (acronym for film-small), a fraction of mixed plastic waste stream obtained by the separation and mechanical recycling of post-consumer packaging films of small size. Physical, chemical and rheological characterization evidenced that Fil-s stream is mainly composed of polyethylene and a smaller fraction of polypropylene. With the purpose to improve the performances of Fil-s, lamellar and acicular organoclays were melt compounded with the recycled material in a twin-screw extruder. Moreover, in order to enhance the compatibility between the polyolefin components and the nanofiller dispersion in the mixed polymer matrix, the functionalization of Fil-s with maleic anhydride (MAH) was realized by reactive extrusion. Morphological, thermal, rheological and mechanical properties of the functionalized materials and the nanocomposite systems were extensively discussed. The positive effect of the MAH-grafting on the compatibilization between the two polyolefin components of Fil-s was pointed out and an interesting improvement in ductility of Fil-s was obtained. The further addition of the nanoclays also significantly increased the stiffness of the systems.
June 2018
Synthesis and application of synergistic azo-boron-BPA / polydopamine as efficient flame retardant for poly(lactic acid)
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Benjamin Tawiah, Bin Yu, Wai Yi Cheung, Shuk Ying Chan, Wei Yang, Bin Fei PLA (Polylactic acid) as a bioplastic polymer has limited applications in areas that require high fire safety due to its inherent flammability and dripping when exposed to flames. In this paper, azo-boron-BPA (AZ-A) and polydopamine (PDA) were synthesized, characterized and incorporated into PLA using the solvent approach and hot compression molding. Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and Raman spectra showed that AZ-A and PDA were successfully synthesized. The flame retardant (FR) properties of synergistic AZ-A/PDA were investigated by vertical burning test, limiting oxygen index (LOI), cone calorimeter and thermogravimetric analysis (TGA). TGA analysis showed that synergistic AZ-A/PDA was generally more efficient in reducing the degradation rate of PLA and gave appreciably much higher char residue compared to the individual FR components. The synergistic AZ-A/PDA achieved V-0 rating with LOI value of 23.7% at 10
June 2018
Isolation and role of polylactic acid-degrading bacteria on degrading enzymes productions and PLA biodegradability at mesophilic conditions
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Tiparporn Bubpachat, Narongrit Sombatsompop, Benjaphorn Prapagdee Enumeration and isolation of polylactic acid (PLA)-degrading bacteria from soils and wastewater sludge were performed on emulsified PLA agar. Two isolates of potent PLA-degrading bacteria, designated as CH1 and WS3, were selected and identified as Stenotrophomonas pavanii and Pseudomonas geniculata, respectively. PLA was presented as a substrate to stimulate production of protease and PLA-degrading enzyme by S. pavanii CH1 and P. geniculata WS3. The optimal pH values for both protease and PLA-degrading enzyme production by S. pavanii CH1 and P. geniculata WS3 were 7.5 and 8.0, respectively. The optimal gelatin concentrations for stimulating protease production in S. pavanii CH1 and P. geniculata WS3 were 0.3% (w/v), while those for PLA-degrading enzyme production in S. pavanii CH1 and P. geniculata WS3 were 0.1 and 0.3% (w/v), respectively. In addition, P. geniculata WS3 had a higher percentage of PLA film-weight loss than that of S. pavanii CH1, corresponding with reduced molecular weight of PLA. A significant increase of lactic acid content in culture broth was directly correlated with the increasing percentage of PLA film-weight loss. Our results clearly demonstrated that P. geniculata WS3, a novel isolated bacterium, has played a substantial role in PLA biodegradation by producing PLA-degrading enzyme and adhering on PLA surface.
June 2018
Impact of curing time on ageing and degradation of phenol-urea-formaldehyde binder
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): D.V. Okhrimenko, A.B. Thomsen, M. Ceccato, D.B. Johansson, D. Lybye, K. Bechgaard, S. Tougaard, S.L.S. Stipp Phenol-urea-formaldehyde (PUF) resin is one of the most important thermosetting polymers. It is widely used in many industrial and construction applications as an organic coating and adhesive. For example, in production of mineral wool for insulation, PUF is used together with the coupling agent (3-aminopropylsilane, APS) and serves as a binder for attaching mineral fibers to each other and to create the necessary mechanical integrity and shape of the final product. However, during ageing under high humidity (95%) and temperature (70
June 2018
Photo-degradation of electrospun composite mats based on poly(D,L-lactide) submicron fibers and zinc oxide nanoparticles
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Heriberto Rodr
June 2018
Behaviour of aeronautical polymer composite to flame: A comparative study of thermoset- and thermoplastic-based laminate
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): E. Schuhler, A. Coppalle, B. Vieille, J. Yon, Y. Carpier The influence of the fire exposure on the degradation mechanism of thin carbon/epoxy and carbon/polyphenylene sulphide (PPS) laminates has been investigated using a propane burner. The burner used in this work is able to provide a controlled and repeatable heating condition, with the test condition of 106
June 2018
Study on the dehydrofluorination of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) copolymer
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Donghan Li, Mingyi Liao This study evaluates the dehydrofluorination of fluoroelastomer (poly(VDF-co-HFP) copolymer) which was dissolved by organic solvent and reacted with different concentrations of KOH and different amount of phase transfer catalyst (PTC) at 20–60
June 2018
Effect of the addition of polyester-grafted-cellulose nanocrystals on the shape memory properties of biodegradable PLA/PCL nanocomposites
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Valentina Sessini, Iv
June 2018
Degradation under composting conditions of lysine-modified polyurethane based on PCL obtained by lipase biocatalysis
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Marina P. Arrieta, Karla A. Barrera Rivera, Castor Salgado, Antonio Mart
June 2018
Kinetics, evolving thermal properties, and surface ignition of carbon fiber reinforced epoxy composite during laser-induced decomposition
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): Nicholas C. Herr, Ashley E. Gonzales, Glen P. Perram The decomposition kinetics, heats of reaction, evolving thermal conductivity and emissivity, and surface ignition conditions of carbon fiber reinforced polymer (CFRP) composites during laser-induced polymer matrix decomposition were investigated. Woven carbon fiber-epoxy panels of different thicknesses were irradiated with a 1.07-
May 2018
Effect of gallic acid and umbelliferone on thermal, mechanical, antioxidant and antimicrobial properties of poly (vinyl alcohol-co-ethylene) films
Publication date: June 2018
Source:Polymer Degradation and Stability, Volume 152 Author(s): F. Luzi, D. Puglia, F. Dominici, E. Fortunati, G. Giovanale, G.M. Balestra, L. Torre Poly(vinyl alcohol-co-ethylene) (EVOH) films containing two different active ingredients (AIs), gallic acid (GA) and umbelliferone (UMB) at 5
May 2018
Editorial Board
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151

May 2018
Hydrolytic degradation kinetics of bisphenol E cyanate ester resin and composite
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): James A. Throckmorton, Greg Feldman, Giuseppe R. Palmese, Andrew J. Guenthner, Kevin R. Lamison, Neil D. Redeker, Patrick N. Ruth Cyanate ester resin systems offer promise for many high-temperature polymer applications, but the potential for many applications is limited due to hydrolytic degradation of the cured polymer network, which can blister the resin, decrease its cross-linking density, and reduce the maximum allowable use temperature. This study examines the hydrolytic degradation of a Bisphenol E dicyanate ester (LECY) and a glass-fiber composite of LECY. Equilibrium water sorption, reaction rates, and glass transition temperature changes are monitored. Despite differences in diffusion and sorption, the glass fiber composite is shown to behave similarly to the neat polymer system in terms of degradation. Results were compared to PT-30 triphenolic cyanate ester, and LECY was determined to have lower equilibrium water sorption values, and a lower degradation rate.

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May 2018
Screening flame retardants using milligram-scale flame calorimetry
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Fernando Raffan-Montoya, Stanislav I. Stoliarov, Sergei Levchik, Eyal Eden A variety of flame retardants and synergistic additives have been developed over the years in order to address the inherent flammability of polymeric materials. Environmental and economic concerns have recently driven industry to replace some of these flame retardants and synergists. Screening for potential replacements can be costly due to a variety of reasons. While some methods have been developed to screen flame retardants in a cost-effective manner, there is currently a need for a method that can also produce high quality data that provide insight into the physics behind the observed behavior during screening. This work proposes the use of Milligram-scale Flame Calorimetry (MFC) as a method to screen flame retardants in a highly quantitative, cost-effective manner. A methodology based on MFC measurements is presented and subsequently implemented using poly (butylene terephthalate) (PBT) as the base polymer and poly (pentabromobenzyl acrylate) (FR-1025) as the base flame retardant. This combination was chosen due to its well-understood behavior and compatibility. Using this polymer and flame retardant as a base, the flame retardant activity of antimony trioxide (ATO), aluminum hypophosphite (AL-HYPO) and a combination of melamine polyphosphate (MPP) and a proprietary formula (SOL-DP) as additives was explored with the proposed methodology. The fact that these measurements were performed with dry-blending of relatively small amounts per composition, as well as the milligram-scale nature of the measurements should represent a significant reduction in testing times and cost with respect to other available screening methods. The results show the outstanding performance of ATO, as measured by reduction in the heat of combustion. ATO performance is shown to be highly synergistic. For AL-HYPO, and MPP + SOL-DP, the performance is lower with respect to ATO. AL-HYPO does not exhibit synergistic behavior, although certain loadings can lead to lower heats of combustion. The complex interactions between FR-1025, MPP and SOL-DP show that some binary interactions are antagonistic while others are synergistic. Insight into the mode of action (gas-phase versus condensed-phase) was also revealed by the methodology with ATO exhibiting gas-phase-dominated activity, AL-HYPO showing a mixture of gas-phase and condensed-phase activity with no single mode standing out, while MPP + SOL-DP being predominantly condensed-phase active. Given a desired performance (for example, a range of desired heat of combustion values), the methodology allows for identification of optimum formulations that lead to said performance.
May 2018
Miscibility and degradation of polymer blends based on biodegradable poly(butylene adipate-co-terephthalate)
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Ainara Sangroniz, Alba Gonzalez, Loli Martin, Lourdes Irusta, Marian Iriarte, Agustin Etxeberria The aim of this work is to analyse the effect of the preparation method on the miscibility of poly(butylene adipate-co-terephthalate) (PBAT) and poly(hydroxy ether of bisphenol A) (PH) blends and to provide a better understanding on the effect of a non-degradable component (PH) in the degradation of biodegradable PBAT. Blends have been prepared by different methods and the miscibility has been studied in a deeper way by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). Depending on the preparation method miscible or partially miscible blends are obtained. Furthermore, for miscible blends the hydrolytic degradation has been carried out for 405 days. It has been observed that adipate sequences on poly(butylene adipate-co-terephthalate) copolymer are more prone to degradation which leads to changes on glass transition temperature, crystallinity and chemical structure. The degradation rate is decelerated with the addition of PH, however the rate is similar or higher than other biodegradable polymers. Therefore the degradation rate can be controlled varying the composition of the blend and tailored materials with adequate properties can be obtained.

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May 2018
Thermally-activated shape memory effect on biodegradable nanocomposites based on PLA/PCL blend reinforced with hydroxyapatite
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Laura Peponi, Valentina Sessini, Marina P. Arrieta, Iv
May 2018
Linear polyamidoamines as novel biocompatible phosphorus-free surface-confined intumescent flame retardants for cotton fabrics
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Amedea Manfredi, Federico Carosio, Paolo Ferruti, Elisabetta Ranucci, Jenny Alongi Eight linear polyamidoamines (PAAs) prepared by polyaddition of amines to bisacrylamides are investigated as intumescent surface-confined flame retardants for cotton textiles. The structure of the amine-derived subunits governs their performances. In ignitability tests, aminoacid-deriving PAAs exposed to direct flame for 10
May 2018
Multi-scale and multi-technique analysis of the thermal degradation of poly(ether ether ketone)
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Emilie Courvoisier, Yoann Bicaba, Xavier Colin The thermal degradation of PEEK has been studied in rubbery state in wide ranges of temperature (between 180 and 320
May 2018
Transparent and soluble polyimide films from 1,4:3,6-dianhydro-D-mannitol based dianhydride and diamines containing aromatic and semiaromatic units: Preparation, characterization, thermal and mechanical properties
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Zhiming Mi, Zhixiao Liu, Jianan Yao, Chunbo Wang, Changjiang Zhou, Daming Wang, Xiaogang Zhao, Hongwei Zhou, Yumin Zhang, Chunhai Chen To develop colorless and soluble polyimide films, a novel dianhydride containing 1,4:3,6-dianhydro-D-mannitol unit, 2,5-bis(3,4-dicarboxyphenoxy)-1,4:3,6-dianhydromannitol dianhydride (IMDA) was synthesized. And two series of polyimides were prepared via a two-step thermal imidization, PI
May 2018
Fully bio-based poly(propylene succinate) synthesis and investigation of thermal degradation kinetics with released gases analysis
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Paulina Parcheta, Iwona Koltsov, Janusz Datta One of the most important information about polyesters is their thermal stability and phase transition temperatures. These characteristics give information about the promising behavior of the polyester during processing. In this work, linear bio-based polyester polyols were prepared with the use of succinic acid and 1.3-propanediol (both with natural origin). As a polycondensation catalyst was used tetraisopropyl orthotitanate (TPT), which different amount was employed. The thermogravimetric analysis allowed to observe high thermal stability and one step of the thermal decomposition. This analysis affirmed also that the catalyst content did not influence the thermal degradation characteristics of the prepared polyols. Nevertheless, it has huge importance in the context of thermal degradation kinetics. It was determined with the use of Ozawa, Flynn, and Wall and Kissinger's methods to verifying catalyst impact on the thermal degradation kinetics. Moreover, probable mechanism of the prepared bio-based polyols thermal degradation was proposed based on the QMS results.
May 2018
Thermal stability of polylactide with different end-groups depending on the catalyst used for the polymerization
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Edyta Wojtczak, Przemys
May 2018
Novel octa-substituted metal (II) phthalocyanines bearing 2,6-di-tert-buthylphenol groups: Synthesis, characterization, electronic properties, aggregation behavior and their antioxidant activities as stabilizer for polypropylene and high density polyethylene
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Mohammad Hossein Salehi, Ali Reza Karimi Novel metallophthalocyanines [M: Co (II), Cu (II), Zn (II), Mn (II)] bearing eight peripheral 2,6-di-tert-buthylphenol groups were successfully synthesized. The new products were studied by FTIR, 1H NMR, MADLI-TOF, UV/VIS spectral data and thermogravimetric analysis. The aggregation behavior of the new phthalocyanines was investigated in different solvents and concentrations. In addition, the antioxidant activities were analyzed through radical scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH). All the new compounds had radical scavenging activity higher than polymer's commercial antioxidant and the highest DPPH activity was obtained from phthalocyanine copper (II). Moreover, the thermooxidative stability of polypropylene (PP) and high density polyethylene (HDPE) with the new antioxidants were assessed by the measurements of the oxidation induction time (OIT), differential scanning calorimetry (DSC) test and melt flow index (MFI) analysis. The results showed that the newly synthesized phthalocyanine complexes could effectively inhibit the oxidation degradation of PP and HDPE.
May 2018
In-depth study of the synthesis of polyamides in the melt using biacetal derivatives of galactaric acid
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Aleksandra A. Wr
May 2018
Effect of combined UV thermal and hydrolytic aging on micro-contact properties of silicone elastomer
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Jian Wu, Kaifang Niu, Benlong Su, Youshan Wang Silicone elastomer seals are widely used in aerospace field due to the unique performance. However, aging and degradation problems still exist under the harsh working environment, such as ultraviolet radiation and high-low temperature. In this paper, combined UV thermal and hydrolytic aging tests have been carried out and the aging mechanism of silicone elastomer is studied by Nicolet 380 ATR-FTIR instrument. Then, fractal surface model of silicone elastomer seal is developed based on the surface topography, which is measured by optical digital microscope. Finally, finite element contact model of the fractal surface is developed to analyze the coupling aging effects on micro-contact characteristics of silicone elastomer. Results indicate that compression set and hardness of silicone elastomer increases when aging time increases; combined UV thermal and hydrolytic aging may lead to the increasement of hardness; contact pressure increases and the contact area decreases in the aging process. Finite element model based on fractal theory provides an effective method to study the micro-contact properties of rubber sealing.
May 2018
Effect of lubricating oil on thermal aging of nitrile rubber
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Xuan Liu, Jiaohong Zhao, Rui Yang, Rossana Iervolino, Stellario Barbera Nitrile rubber (NBR) was thermally aged in air, a commercial lubricating oil, and its corresponding base oil. During thermal aging, changes in the volatile components of NBR, including additives from NBR and the commercial lubricating oil, and the chemical structure of NBR, including functional groups and crosslinking density, were studied by using pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and time domain nuclear magnetic resonance (TD-NMR). The migration of additives and the degree of oxidation and crosslinking of NBR in different media were compared. Three effects of lubricating oil—a barrier effect, consumption of oxygen, and permeation—on thermal aging of NBR were examined. Base oil protected the rubber from serious oxidation and crosslinking due to the barrier effect and consumption of oxygen. In contrast, the commercial oil accelerated the aging of NBR by extracting and reacting with the additives from NBR and permeating into the rubber to promote oxidation and crosslinking of the rubber chains. The presence of additives in the commercial oil was the main reason for the different performances. These results were meaningful for using NBR products in lubricating oil conditions.
May 2018
Synthesis and application of a mono-component intumescent flame retardant for polypropylene
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Changjiang Zhu, Mingshan He, Yu Liu, Jianguang Cui, Qilong Tai, Lei Song, Yuan Hu A novel mono-component intumescent flame retardant, named as hyper-branched triazine-piperazine pyrophosphate (HTPPP), is synthesized by using cyanuric chloride, 1-boc-piperazine and phosphoric acid. Chemical structures of HTPPP are characterized by fourier transform infrared (FTIR) spectra, 31P nuclear magnetic resonance (NMR), solid-state 13C NMR, elemental analysis (EA) and inductively coupled plasma mass spectrometer (ICP-MS). The resulting HTPPP is used alone as an intumescent flame retardant for polypropylene (PP). PP/HTPPP composite can achieve a limiting oxygen index (LOI) value of 30.5% and the vertical burning test (UL-94) V-0 rating at 25
May 2018
Influence of tannin containing coatings on weathering resistance of wood: Water based transparent and opaque coatings
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Eylem D. Tomak, Ferhat Arican, Oktay Gonultas, Ebru D. Sam Parmak The aim of this study was to improve weathering resistance of Scots pine wood by treating the surfaces with water based transparent and opaque wood coatings containing valex, mimosa and pine tannins. Samples coated with tannin containing coatings with various concentrations were exposed to artificial weathering for 1512
May 2018
Flame retardant efficiency of KH-550 modified urea-formaldehyde resin cooperating with ammonium polyphosphate on polypropylene
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Ying Ren, Dandan Yuan, Wenmin Li, Xufu Cai This paper surveys the char forming effect of urea-formaldehyde resin (UF) and the flame retardancy of UF cooperating with ammonium polyphosphate (APP) for polypropylene (PP). UF was firstly synthesized and then modified by a silane coupling agent 3-aminopropyltriethoxysilane (KH-550). UF and KH-550 modified urea-formaldehyde resin (M-UF) were characterized by field-emission scanning electron microscope (FE-SEM), energy-dispersive analysis (EDS), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Compared with UF, M-UF had better thermal stability and higher mass of residue char. Afterwards the intumescent flame retardants (IFRs), consisting of UF + APP and M-UF + APP respectively, were introduced into PP. The flame retardant efficiency of PP composites was investigated by limiting oxygen index (LOI), UL-94 vertical burning, and micro combustion calorimetry (MCC). The possible decomposition mechanisms were investigated by TGA, FT-IR and EDS. When the addition of PP, APP and UF was 70, 24 and 6 wt%, the LOI value reached 23.5 and UL-94 test could not pass. However, when the loading of PP, APP and M-UF was 70, 20 and 10 wt%, the LOI value reached 29.5 and UL-94 test was V-0. The residual char layers of some PP composites were analyzed by Laser Raman spectroscopy (LRS) and FE-SEM. The LRS and FE-SEM presented that the char layer of 20%APP+10%M-UF/PP was more compact and had higher strength than 20%APP+10%UF/PP. Furthermore, tensile tests showed that M-UF/APP could improve break strength and toughness for PP compared with the same ratio of UF/APP. To sum up, M-UF + APP/PP have better flame retardant efficiency and tensile properties compared with UF + APP/PP.
Available online 25 April 2018
Two-dimensional cardanol-derived zirconium phosphate hybrid as flame retardant and smoke suppressant for epoxy resin
Publication date: May 2018
Source:Polymer Degradation and Stability, Volume 151 Author(s): Xian-Ling Fu, Xin Wang, Weiyi Xing, Ping Zhang, Lei Song, Yuan Hu A new hybrid cardanol-derived zirconium phosphate (CZrP) was successfully synthesized from renewable resource cardanol and its structure was well characterized by nuclear magnetic resonance (NMR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). As a comparison, EP composite containing zirconium phosphate (ZrP) was also prepared using the same procedure. XRD result demonstrated that CZrP displayed more than 5-fold interlayer spacing than pristine ZrP. As a result, the enlarged interlayer spacing of CZrP facilitated the homogeneous dispersion of the nanoadditive in the epoxy matrix. With only 6
Available online 24 April 2018
Radiation stability of silicon-organic varnish modified with nanoparticles
Publication date: Available online 25 April 2018
Source:Polymer Degradation and Stability Author(s): M.M. Mikhailov, V.V. Neshchimenko, A.V. Grigorevskiy, A.N. Sokolovskiy, A.S. Bakhtaulova, I.S. Vaschenkov An effect of SiO2 nanoparticles modification on spectra and integral absorption coefficient of silicon-organic varnish KO-859 before and after 30
Available online 23 April 2018
Diffusion and hydrolysis effects during water aging on an epoxy-anhydride system
Publication date: Available online 24 April 2018
Source:Polymer Degradation and Stability Author(s): Guillermina Capiel, Julieta Uicich, Diana Fasce, Pablo E. Montemartini Hydrothermal aging of an epoxy-anhydride network has been studied by means of gravimetric analysis, Fourier transform infrared spectroscopy (FTIR) and modulated differential scanning calorimetry (MDSC). The long-term aging results revealed a fourth stage mechanism in which an initial short diffusional period is followed by the hydrolysis of the ester groups. Degraded materials showed two values of glass transition temperature suggesting a heterogeneous process. Hydrolysis undergoes in preferential sites due to the catalytic effect of the carboxyl acids formed during the chemical degradation. Domains with low crosslinking density and high mobility are formed. At long degradation time, samples presented a unique glass transition temperature around 50
Available online 23 April 2018
Getting a better insight into the chemistry of decomposition of complex flame retarded formulation: New insights using solid state NMR
Publication date: Available online 23 April 2018
Source:Polymer Degradation and Stability Author(s): N. Hansupo, G. Tricot, S. Bellayer, P. Roussel, F. Samyn, S. Duquesne, M. Jimenez, M. Hollman, P. Catala, S. Bourbigot This paper aims at developing an innovative approach to characterize the char residue of an intumescent coating obtained after a UL1709 furnace test. The intumescent formulation is based on an epoxy resin and contains numerous additives including zinc borate, ammonium polyphosphate and silicate fibers. The purpose is to characterize the numerous reactions that can occur upon burning using crossed methods including Electron Probe Micro-Analysis (EPMA), X-ray diffraction (XRD) and 1D/2D solid state Nuclear Magnetic Resonance (NMR). In particular, it emphasizes the potential of the advanced NMR technique namely two-dimensional Dipolar Heteronuclear Multiple Quantum Correlation (2D D-HMQC) NMR. As a result, EPMA evidenced that B/P and B/Si are located in the same domain suggesting the formation of boron-phosphorus and/or boron-silicone containing compounds on the sample surface. H3BO3 was identified by XRD as a main crystalline specie, additional species (e.g. SiO2, Zn4O(BO2)6) were also identified. The borate, silicate and phosphate chemical species were then characterized using 1D NMR but no definitive assignments could be given. To specify those assignments, 2D D-HMQC NMR was performed and the formation of amorphous borophosphates and borosilicates was evidenced emphasizing the chemical reactivity between the ingredients of the formulation. It was suggested that these species allow reinforcing the char and improving the fire protective properties of the coatings. This work highlights the particular interest of advanced NMR technique, which provides unique information on the characterization of intumescent char.

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Available online 22 April 2018
A reactive phosphorus-containing polyol incorporated into flexible polyurethane foam: Self-extinguishing behavior and mechanism
Publication date: Available online 23 April 2018
Source:Polymer Degradation and Stability Author(s): Wen-Hui Rao, Zong-Min Zhu, Shui-Xiu Wang, Ting Wang, Yi Tan, Wang Liao, Hai-Bo Zhao, Yu-Zhong Wang A novel liquid phosphorus-containing polyol named as PDEO was prepared via reactions between ethylene glycol and phenylphosphonic dichloride. PDEO reacts with the -NCO-terminated prepolymers and forms urethane linkages in the chain extension reaction step, thus, it was used to prepare inherently flame-retardant flexible polyurethane foams (FPUFs). The structure and properties of flame-retardant FPUF were characterized by scanning electron microscopy (SEM), tensile measurements, limiting oxygen index (LOI), vertical burning tests, cone calorimeter tests and thermogravimetric analysis (TGA). The vertical burning test demonstrated that fire extinguished instantly after the withdrawn of the pilot flame, while the PDEO loading was only 10 php. In addition, the persistent flame retardancy of PDEO in FPUFs was proved by thermal ageing test. The corresponding flame-retardant mechanism of PDEO-containing FPUFs was investigated by pyrolysis gas chromatography mass spectrometry (Py-GC/MS), X-ray photoelectron spectroscopy (XPS), SEM and FTIR, and the results indicated a gaseous phase dominated flame-retardant mechanism of PDEO.
Available online 22 April 2018
Synergistic effects of synthetic phosphonium sulfonates with expandable graphite on flame retardancy for EVA rubber blends
Publication date: Available online 22 April 2018
Source:Polymer Degradation and Stability Author(s): Shijie Hou, Yong Jian Zhang, Pingkai Jiang Synergistic effects of synthetic phosphonium sulfonates (PhSs) bearing different groups with expandable graphite (EG) on flame retardancy properties in poly(ethylene-co-vinyl acetate) (EVA) rubber blends have been studied by limiting oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), and thermogravimetric analysis (TGA). The EVA/EG/PhS composites revealed excellent flame retardancies. Upon adding 2.5

Effects of ZnO quantum dots on the photostability of acrylate photopolymers used as recording materials
Publication date: Available online 22 April 2018
Source:Polymer Degradation and Stability Author(s): Georgia G. Goourey, Pascal Wong-Wah-Chung, Lavinia Balan, Ya
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