bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic acids catalyzed polymerization of ε‐caprolactone: Synthesis and characterization
Authors: Oledzka Ewa , Narine Suresh S. 
Published: August 2010

AbstractEnvironmentally friendly organocatalytic synthesis of aliphatic polyesters was studied. The catalysis investigated is novel, and lends itself well to the potential production of valuable biodegradable products. The reactions were based on an organic acids‐catalyzed ring‐opening polymerization of ε‐caprolactone with fatty acid derivatives as the initiator and were performed in the absence of solvents. The chemical structures of the functionalized polymers were confirmed by1H and13C‐NMR spectra. Polymers with different molecular weights, in the range 10,900–15,200 were obtained in the presence of fumaric acid as catalyst. The thermal properties of the functionalized PCLs were determined by modulated differential scanning calorimetry and thermogravimetric analysis. The MDSC results verified that the crystallinity and the melting point of the lipid‐functionalized polymers were lower than that of the unfunctionalized poly(ε‐caprolactone). The hydrolytic degradation of the functionalized polymer was also investigated. The result shows the degradation rate was affected by the presence of oleic acid derivatives in the polymer molecule. The lipid‐functionalized polymers synthesized by the metal‐free polymerization systems seem to be suitable biodegradable polyesters for use in biomedical and pharmacological applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of novel lipid functionalized poly(ε‐caprolactone)s
Authors: Oledzka E. , Kong X. , Narine S. S. 
Published: August 2010

AbstractA series of novel lipid functionalized poly(ε‐caprolactone)s (PCLs) were synthesized through ROP of ε‐caprolactone in the presence of threo‐9,10‐dihydroxyoctadecanoic acid, synthesized from oleic acid. PCLs with different molecular weights were obtained by controlling the molar ratio of the initiator to the monomer. DSC and XRD analysis indicate that the crystallinity of PCLs decreased when compared to unfunctionalized PCL. The enzymatic degradation study shows that for samples with lower lipid derivatives content, a higher enzymatic degradation rate was observed because the lipase enzymes attack the ester bonds of the polymer; increased lipid content therefore inhibits the action of the lipase enzymes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of poly(D,L‐lactic acid) modified by triethanolamine by direct melt copolycondensation and its characterization
Authors: Luo Yu‐Fen , Wang Zhao‐Yang , Ye Rui‐Rong , Luo Shi‐He , Yang Li‐Ting 
Published: August 2010

AbstractUsing D,L‐lactic acid (LA) and multifunctional group compound triethanolamine (TEA) as starting materials, a novel biodegradable material poly(D,L‐lactic acid‐triethanolamine) [P(LA‐TEA)] was directly synthesized by simpler and practical melt polycondensation. The appropriate synthetic condition was discussed in detail. When the molar feed ratio LA/TEA was 30/1, the optimal synthesis conditions were as follows: a prepolymerization time of 12 h; 0.5 weight percent (wt %) SnO catalyst; and melt copolycondensation for 8 h at 160°C, which gave a novel star‐shaped poly(D,L‐lactic acid) (PDLLA) modified by TEA with the maximum intrinsic viscosity [η] 0.93 dL g−1. The copolymer P(LA‐TEA) as a different molar feed ratio was characterized by [η], Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H‐NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). Increasing the molar feed ratio of LA/TEA, Tg and Mw increased. However, all copolymers were amorphous, and their Tg (12.2°C–32.5°C) were lower than that of homopolymer PDLLA. The biggest Mw was 9400 Da, which made the biodegradable polymer be potentially used as drug delivery carrier, tissue engineering material, and green finishing agent in textile industry. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Nanoclay filled soy‐based polyurethane foam
Authors: Liang Kaiwen , Shi Sheldon Q. 
Published: August 2010

AbstractPolyurethane foam was fabricated from polymeric diphenylmethane diisocyanate (pMDI) and soy‐based polyol. Nanoclay Cloisite 30B was incorporated into the foam systems to improve their thermal stabilities and mechanical properties. Neat polyurethane was used as a control. Soy‐based polyurethane foams with 0.5–3 parts per hundred of polyols by weight (php) of nanoclay were prepared. The distribution of nanoclay in the composites was analyzed by X‐ray diffraction (XRD), and the morphology of the composites was analyzed through scanning electron microscopy (SEM). The thermal properties were evaluated through dynamic mechanical thermal analysis (DMTA). Compression and three‐point bending tests were conducted on the composites. The densities of nanoclay soy‐based polyurethane foams were higher than that of the neat soy‐based polyurethane foam. At a loading of 0.5 php nanoclay, the compressive, flexural strength, and modulus of the soy‐based polyurethane foam were increased by 98%, 26%, 22%, and 65%, respectively, as compared to those of the neat soy‐based polyurethane foam. The storage modulus of the soy‐based polyurethane foam was improved by the incorporation of nanoclay. The glass transition temperature of the foam was increased as the nanoclay loading was increased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Studies on the physico‐mechanical, thermal, and morphological behaviors of high density polyethylene/coleus spent green composites
Authors: Syed Murtuza Ali , Akhtar Sania , Siddaramaiah  , Syed Akheel Ahmed 
Published: August 2010

AbstractThis study is aimed at utilizing nutraceutical industrial waste and reducing carbon footprints of plastics. Eco‐friendly “green composites” of high density polyethylene (HDPE) were fabricated using coleus spent (CS)—a nutraceutical industrial waste as reinforcing filler and maleic anhydride‐graft‐polyethylene (MA‐g‐PE) as compatibilizer. Composites were fabricated with 5, 10, 15, and 20% (w/w) of CS by extrusion method. The fabricated HDPE/CS composites were evaluated for mechanical and thermal behavior. A slight improvement of about 5% in tensile strength and marked improvement of about 25% in tensile modulus for 20 wt % CS filled HDPE composites was noticed. The effect of CS content on rheological behavior was also studied. Thermal characteristics were performed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA thermogram indicated increased thermal stability of CS‐filled composites. From TGA curves the thermal degradation kinetic parameters of the composites have been calculated using Broido's method. The enthalpy of melting (ΔHm) obtained from DSC curves was reduced with increase in CS content in HDPE matrix, due to decrease in HDPE content in composite systems. An increase in CS loading increased the water absorption behavior of the composites slightly. Morphological behavior of cryo‐fractured composites has been studied using scanning electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Factorial optimization of the effects of extrusion temperature profile and polymer grade on as‐spun aliphatic–aromatic copolyester fibers. II. Crystallographic order
Authors: Younes Basel , Fotheringham Alex 
Published: August 2010

AbstractBy using factorial experimental design, a range of crystallographic orders for as‐spun linear aliphatic–aromatic copolyester fibers have been characterized with the aid of wide angle X‐ray diffraction measurements. Full‐Width Half‐Maximum of an X‐ray scattering profile (FWHM) has been quantitatively assessed as responses to polymer grades denoted by melt flow index (MFI) and to extrusion temperature zones in the extrusion equipment used to produce the as‐spun fibers. With the advantages of the factorial experimental design in the development of fiber process technology, the enhanced statistical approach specifies the direction of change of the polymer's melt flow index and extrusion temperature profile for increasing or reducing crystallographic order. The produced as‐spun aliphatic aromatic copolyester fiber is an environmentally‐friendly attractive, alternative to conventional chemical fibers for different applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of multiwalled carbon nanotubes on crystallization behavior of poly(vinylidene fluoride) in different solvents
Authors: He Linghao , Sun Jing , Zheng Xiaoli , Xu Qun , Song Rui 
Published: August 2010

AbstractIn this study, the poly(vinylidene fluoride) (PVDF)—multiwalled carbon nanotubes (MWNTs) composites have been prepared by solution casting in two different solvents: dimethyl sulfoxide (DMSO) and dimethylacetamide (DMAc). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) results showed that the crystal phases of PVDF are quite different in the two solvents. When DMSO is used as the solvent, the PVDF crystalline phases could be greatly alternated from α‐form to β‐form by the incorporation of MWNTs. While the crystalline structure of PVDF hardly change in the case of DMAc. The DSC and polarized optical microphotographs implied that MWNTs not only act as nucleating agents for PVDF but also confine the crystallization of PVDF. Besides, it was found that the storage modulus (E′) of the composites were significantly enhanced with an appropriate content of MWNTs. And when using DMSO as the solvent, one relaxation process emerges in the loss tan δ (loss factor) curves of the neat PVDF and PVDF/MWNTs composites, while it was not observed in the DMAc system. The obtained results revealed that varing solvents have different effects on the crystallization behavior of PVDF with the addition of MWNTs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Pineapple leaf fiber reinforced thermoplastic composites: Effects of fiber length and fiber content on their characteristics
Authors: Chollakup Rungsima , Tantatherdtam Rattana , Ujjin Suchada , Sriroth Klanarong 
Published: August 2010

AbstractPineapple leaf fiber (PALF) was used as a reinforcement in polyolefins. Polypropylene (PP) and low‐density polyethylene (LDPE) composites with different fiber lengths (long and short fibers) and fiber contents (0–25%) were prepared and characterized. The results showed that the tensile strength of the composites increased when the PALF contents were increased. It was observed that the composites containing long fiber PALF were stronger than the short fiber composites as determined by greater tensile strength. An SEM study on the tensile fractured surface confirmed the homogeneous dispersion of the long fibers in the polymer matrixes better than dispersion of the short fibers. The unidirectional arrangement of the long fibers provided good interfacial bonding between the PALF and polymer which was a crucial factor in achieving high strength composites. Reduction in crystallinity of the composites, as evident from XRD and DSC studies suggested that the reinforcing effect of PALF played an important role in enhancing their mechanical strength. From the rule of mixtures, the stress efficiency factors of the composite strength could be calculated. The stress efficiency factors of LDPE were greater than those of PP. This would possibly explain why the high modulus fiber (PALF) had better load transfers to the ductile matrix of LDPE than the brittle matrix of PP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Compatibilizing effect of functionalized polyphosphazene on the properties of poly(phenylene oxide)/vectra a blend system
Authors: Bose S. , Das C. K. , Saxena A. K. , Ranjan A. 
Published: August 2010

AbstractThe effect of functionalized polyphosphazene on the thermal, rheological, and morphological properties of PPO (poly(phenylene oxide))/liquid crystalline polymer (Vectra A) blend has been investigated by means of the capillary rheometry, mechanical testing, and scanning electron microscopy (SEM) in this study. The rheological measurements show that compatibilized blends exhibit substantial rise in viscosity in comparison to uncompatilized blend especially pronounced at lower shear rates which results in improved interfacial adhesion. DMA study highlights that polyphosphazene could be used as an effective compatibilizer for the concerned blend system. SEM study reveals fine fibrillation of liquid crystalline polymers in presence of compatibilizer and the fibers are oriented in the direction of flow field. The mechanical properties of the ternary blends are increased when a proper amount of polyphosphazene is added. This is attributed to fine strand generation induced via the addition of polyphosphazene. Enhanced adhesion at the interface invokes better elongation in the ternary blends. However, mechanical properties deteriorate considerably when polyphosphazene content is 5 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of readily soluble polyarylates derived from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A and aromatic diacid chlorides
Authors: Liu Pengqing , Wu Ting , Shi Meiwu , Ye Guangdou , Xu Jianjun 
Published: August 2010

AbstractA series easily soluble polyarylates were synthesized from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A with various aromatic diacid chlorides by the two‐phase interfacial polycondensation. These polyarylates have the inherent viscositiesin the range of 0.36–0.97 dL/g, and their number‐average and weight‐average molecular weights determined by gel permeation chromatography are 14,200–43,200 and 31,900–102,500, respectively. All these polyarylates are readily soluble in a wide range of organic solvents, thus these polymers can be convenient to process into heat resistance films by cast, spin‐ or dip‐coating. The polyarylates have the glass transition temperatures in the range of 165.0–201.6°C. The pendent phenyl‐containing polyarylates reveal excellent thermal stability, and their initial degradation temperatures are all above 480°C and char yields at 700°C are 37.97–40.53% in nitrogen atmosphere. However, the polymers prepared from tetramethylbisphenol A have a large decrease in thermal stability, and their initial degradation temperatures in nitrogen are only about 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Shear and extensional rheology and flow‐induced orientation of carbon nanofiber/polystyrene melt composites
Authors: Miyazono Koki , Kagarise Christopher D. , Koelling Kurt W. , Mahboob Monon , Bechtel Stephen E. 
Published: August 2010

AbstractThe rheological behavior and morphology of polystyrene/carbon nanofiber (PS/CNF) composites in their melt phase have been characterized through experimental measurements. Viscosity measurements of the PS/CNF composites in the linear viscoelastic regime show the ratio of the transient extensional viscosity to the transient shear viscosity to be greater than three, the Trouton ratio. This behavior is due to differences in the flow‐induced orientation of CNFs in shear and extensional flow. The orientation development of the CNFs in shear and extensional flow was analyzed through a method utilizing transmission electron microscopy and was used to explain observed rheological phenomena. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Retracted: Microencapsulation of intumescent flame‐retardant agent and application to epoxy resins
Authors: Gao Ming , Wo Yaqi , Wu Weihong 
Published: August 2010

AbstractThe following article from the Journal of Applied Polymer Science, “Microencapsulation of intumescent flame‐retardant agent and application to epoxy resins,” by Ming Gao, Yaqi Wo, and Weihong Wu, published online on 25 August 2010 in Wiley Online Library (J. Appl. Polym. Sci. 2011, 119, 2025; http://onlinelibrary.wiley.com/doi/10.1002/app.32930/full), has been retracted by agreement between the authors, the journal's editors, and Wiley Periodicals, Inc. The retraction has been agreed because a pervasive misattribution of data resulted in fundamentally flawed experimental results, thus rendering the article's subsequent discussion and conclusions meaningless and misleading.
Decomposition rate control of PLLA plate by heat treatment
Authors: Nakagawa Masafumi , Teraoka Fumio , Sohmura Taiji 
Published: August 2010

AbstractIt is difficult to control the decomposition rate and the mechanical property of scaffolds after forming the poly(L‐lactide) (PLLA) scaffolds. The purpose of this study is to control the decomposition rate and mechanical properties of the PLLA plate after forming. We carried out accelerated decomposition experiments using the enzyme on the (PLLA) with various crystallinity, which were prepared by changing the heat treatment condition, and elucidated the relationship between the crystallinity and the decomposition rate. A high positive correlation was observed between the heat treatment temperature and the crystallinity. A high negative correlation was observed between the crystallinity and the decomposition rate. Using the obtained empirical formula, it became possible to calculate the required period to decompose a certain amount of the PLLA if the heat treatment temperature was known. Changing the crystallinity of the PLLA plate could arbitrarily control the decomposition rate of the PLLA plate after forming. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Fabrication of inorganic/polymer nanocomposite membranes containing very high silica content via in situ surface grafting reaction and reactive dispersion of silica nanoparticles: Proton conduction, water uptake, and oxidative stability
Authors: Kim Ju‐Young , Ohn Young‐Hwan , Ihn Kyo‐Jin , Lee Changhyun 
Published: August 2010

AbstractIn this study, we present a new fabrication process for proton exchange membranes based on inorganic/organic nanocomposite using in situ surface grafting reaction and reactive dispersion of silica nanoparticles in the presence of reactive dispersant, urethane acrylate nonionomer (UAN). Through in situ surface grafting reaction of silica nanoparticles, urethane acrylates were chemically introduced on the surface of silica nanoparticles, which were dispersed in DMSO solutions containing UAN and sodium styrene sulfonate (NaSS). After urethane linkage and copolymerization of NaSS, UAN and urethane acrylate moieties of silica nanoparticles, the solutions were converted to silica nanoparticle‐dispersed proton exchange membranes where silica particles were chemically connected with organic polymer chains. 5.89–29.45 wt % of silica nanoparticles could be dispersed and incorporated in polymer membranes, which were confirmed by transmittance electron microscopy (TEM) measurement. On varying weight % of silica nanoparticles dispersed within the membranes, water uptake and oxidative stability of nanocomposite membranes were largely changed, but membranes showed almost the same proton conductivity (greater than 10−2 S cm−1). At 5.89 wt % of silica nanoparticles, nanocomposite membranes showed the lowest water uptake and excellent oxidative stability compared to the sulfonated polyimide membranes fabricated by us. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of controlled electron beam irradiation on the rheological properties of nanosilica‐filled LDPE‐EVA based thermoplastic elastomer
Authors: Hui S. , Mushtaq S. , Chaki T. K. , Chattopadhyay S. 
Published: August 2010

AbstractThe effect of controlled electron beam irradiation on the rheological properties of a model LDPE‐EVA thermoplastic elastomer (TPE) system filled with silica nanoparticles is explored in this article. The pristine silica particles were mixed with LDPE‐EVA system in molten condition by varying the sequence of addition and amount of nanosilica. In one composition, Si69 was used to improve the state of dispersion of nanosilica. The rheological behavior of irradiated TPE systems is influenced remarkably by irradiation dose, loadings of silica, variation of sequence, and addition of Si69. All filled TPE systems register an increase in elastic response with increasing frequency and with increase in irradiation dose. Upon irradiation, melt viscosity increases when compared with the unirradiated samples because of the crosslinking effect and improvements in interfacial bonding. The viscoelastic response varies markedly with the temperature. The radiation sensitizing effect of silica is reflected from the rheological data. The dynamic and steady shear rheological properties do not follow a simple correlation. Finally, the rheological behavior is correlated with the morphology of the irradiated systems processed at various shear rates. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal stability and flame retardancy of polyester, cotton, and relative blend textile fabrics subjected to sol–gel treatments
Authors: Alongi Jenny , Ciobanu Mihaela , Tata Jennifer , Carosio Federico , Malucelli Giulio 
Published: August 2010

AbstractPolyester (PET), cotton (COT), and two relative blend textile fabrics were treated by sol–gel processes. Tetraethoxysilane (TEOS) was used as inorganic precursor of silica phases; furthermore, different TEOS/H2O ratios were examined to explore the effect of the presence of SiO2 on the thermal and fire stability of the textile fabrics investigated. The distribution and dispersion of SiO2 were observed by means of scanning electronic microscopy (SEM). SEM magnifications showed the formation of a continuous silica film located in the neighboring fibers; furthermore, in the case of PET, such a film incorporated silica particles with an average diameter ranging between 0.2 and 6 μm. The thermal and thermooxidative stabilities of the treated samples were investigated by thermogravimetric analysis: after the sol–gel treatment, the degradation mechanism was modified both in nitrogen and in air, and the improvement in the thermal stability was attributed to the presence of silica, which played a protective role in the degradation of the textile fabrics. Finally, we investigated the combustion behavior of the textile fabrics by cone calorimetry, measuring the time to ignition, the heat release rate, and the relative peak. The former was found to depend on the type of fabric; the latter generally evidenced a remarkable decrease for all of the treated samples, up to 35% compared to the neat counterparts. This indicated that the sol–gel treatments improved the flame retardancy of the PET/COT fabrics. This conclusion was also confirmed by limiting oxygen index tests, which evidenced burning kinetics changes in the presence of the silica coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The role of the disposition of the recycled polymer on the properties of films for greenhouses coverage
Authors: Dintcheva N. Tz. , La Mantia F. P. , Cascone M. , Balloni A. 
Published: August 2010

AbstractMultilayer films, by using postconsumer materials in the central layer, i.e., multilayer composition: virgin polyethylene/postconsumer polymer/virgin polyethylene, allows to get a film for greenhouses coverage with good mechanical properties and photo‐oxidation resistance, similar to that of the films made from virgin material and certainly better than the photo‐oxidation resistance of the film made melt blending the virgin polyethylene and the postconsumer polymer. Moreover, the disposition of the postconsumer polymer containing oxygenated groups only in the central layer determines a significant slowdown of the photo‐oxidation process of the multilayer film although faster than of the pristine vPE film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011