Biodegradation and thermal properties of crosslinked chitosan/corn cob biocomposite films by electron beam irradiation

Thermal and biodegradation properties of chitosan (CS)/corn cob (CC) biocomposite films and their irradiation‐crosslinked were tested. The CS/CC biocomposite films after irradiation showed better thermal stability and lower weight loss in enzymatic and soil biodegradation in comparison with unirradiated CS/CC biocomposite films due to the formation of new bonds (radiation‐induced crosslinks). The surface erosion for biodegraded biocomposite films were examined by scanning electron microscope. Furthermore, the formation of new bonds in irradiated biocomposite films were analyzed by Fourier transform infrared spectroscopy. POLYM. ENG. SCI., 59:E59–E68, 2019. © 2018 Society of Plastics Engineers     

Characterization and Properties of Treated Oil Palm Empty Fruit Bunch Regenerated Cellulose Biocomposite Films with Butyl Methacrylate Using Ionic Liquid

Regenerated cellulose biocomposite films from oil palm empty fruit bunch and microcrystalline cellulose were prepared using N,N-dimethylacetamide and lithium chloride. The effects of oil palm empty fruit bunch contents and butyl methacrylate on properties of regenerated cellulose biocomposite films were investigated. At 2?wt% of untreated oil palm empty fruit bunch content showed highest crystallinity index, tensile strength, modulus of elasticity, and thermal stability but lower elongation at break than other oil palm empty fruit bunch content. The treated regenerated cellulose biocomposite films with butyl methacrylate showed better tensile strength, modulus of elasticity, thermal stability, and crystallinity index while Fourier transform infrared spectroscopy study showed interaction between cellulose and butyl methacrylate.     

改性淀粉/LLDPE共混体系生物降解材料性能的研究

将自制接枝改性淀粉与LLDPE、玉米淀粉以及另外两种相容剂进行共混。通过对共混体系的形态结构、力学性能、流变性能、热性能以及对共混物薄膜的生物降解性能等的研究说明:复合相容剂MAH-g-PE+LA-g-starch的加入改善了淀粉和LLDPE的相容性,使得共混物体系具有适宜的拉伸强度及断裂伸长率;LLDPE/淀粉/(MAH-g-PE+LA-g-starch)共混物薄膜具有很好的生物降解性能。     

Characteristics of soy protein isolate‐montmorillonite composite films

Soy protein isolate/montmorillonite (SPI/MMT) nanocomposite films were prepared in which MMT was used as a nanofiller at 0, 3, 6, 9, 12, and 15 wt % relative to SPI dry weight. Effects of MMT on film properties including tensile strength, elongation at break, total soluble matter, water vapor permeability, and oxygen permeability were assessed. X‐ray diffraction patterns were determined, and morphologies of SPI and the SPI‐MMT composite films were visualized by scanning electron microscopy. Mechanical and barrier properties were improved by evidenced increases in tensile strength and modulus, and decreases in permeability to water vapor and oxygen. MMT concentrations of 3%–12% were optimal for improving functional properties of the composite films. X‐ray diffraction and scanning electron microscopy examinations revealed the formation of an intercalated and exfoliated structure on the addition of MMT into the SPI matrix. We conclude that intercalated and exfoliated MMT silicates enhance mechanical and barrier properties of SPI films. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

碳纤维改性HA/PMMA生物复合材料力学性能的研究

采用原位合成与溶液共混相结合的方法,制备了短切碳纤维增强纳米羟基磷灰石(HA)/聚甲基丙烯酸甲酯(PMMA)生物复合材料。研究了碳纤维的含量和长度对HA/PMMA复合材料结构和力学性能的影响。采用万能材料试验机和扫描电子显微镜对复合材料的力学性能及断面的微观形貌进行了测试和表征。结果表明:碳纤维在HA/PMMA复合材料中分布均匀,有效提高了复合材料的力学性能;碳纤维含量为4%时,复合材料的拉伸强度、弯曲强度、压缩强度和弹性模量等均达到最大值;复合材料的断裂伸长率随碳纤维含量的增加而减小;当碳纤维含量一定时,随其长度的增加,复合材料的拉伸强度、弯曲强度和弹性模量均增加,但断裂伸长率降低。     

Mechanical and barrier properties of polyvinyl chloride plasticized with dioctyl phthalate,epoxidized soybean oil,and epoxidized cardanol

Plasticized polyvinyl chloride (PVC) films were prepared by melt compounding and compression molding using epoxidized cardanol (EC), a biobased plasticizer and its plasticization effect was compared with epoxidized soybean oil (ESBO) and dioctyl phthalate (DOP). The mechanical, migration, thermal, and barrier properties of the plasticized films were compared. The effect of replacing DOP with EC on the properties of PVC films was also investigated. The tensile strength, elongation at break, tensile modulus and impact strength values of PVC/EC films were higher in comparison to PVC/DOP and PVC/ESBO films at a fixed plasticizer loading of 40 wt.%. Also, the films prepared with a mixture of DOP + EC showed higher tensile strength and elongation at break compared to that of films prepared with only DOP. The PVC/EC films showed good thermal stability and reduced oxygen transmission rate (OTR) compared to PVC/DOP films. The addition of graphene and nanoclay in the PVC/plasticizer system exhibited an increase in oxygen transmission. However, the oxygen barrier property of nano filler incorporated PVC/EC films was better than PVC/DOP films. All the films showed negligible water vapor transmission rate (WVTR).     

Effect of talc on the properties of polypropylene/ethylene/propylene/diene terpolymer blends

In the present study, the effect of talc content on the mechanical, thermal, and microstructural properties of the isotactic polypropylene (i‐PP) and elastomeric ethylene/propylene/diene terpolymer (EPDM) blends were investigated. In the experimental study, five different talc concentrations, 3, 6, 9, 12, and 15 wt %, were added to i‐PP/EPDM (88/12) blends to produce ternary composites. The mechanical properties such as yield and tensile strengths, elongation at break, elasticity modulus, izod impact strength for notch tip radius of 1 mm, and hardness with and without heat treatments and thermal properties, such as melt flow index (MFI), of the ternary composites have been investigated. The annealing heat treatment was carried out at 100°C for holding time of 75 h. From the tensile test results, an increased trend for the yield and tensile strengths and elasticity modulus was seen for lower talc contents, while elongation at break showed a sharp decrease with the addition of talc. In the case of MFI, talc addition decreased the MFI of i‐PP/EPDM blends. It was concluded that, taking into consideration, mechanical properties and annealing heat treatment, heat treatment has much more effect on higher yield and tensile strengths, elongation at break, elasticity modulus, impact strength, and hardness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3033–3039, 2006     

热塑性淀粉塑料的力学性能研究

以淀粉和增塑剂为原料制备了热塑性淀粉 (TPS)塑料及TPS/EVA共混材料 ,研究了材料的力学性能。结果表明 :TPS塑料的拉伸强度和弹性模量随着增塑剂用量的增加而降低 ,断裂伸长率和冲击强度则随之升高 ;用量相同时 ,3种增塑剂对TPS塑料的冲击强度和断裂伸长率的改善程度依次为 :乙二醇 >丙三醇 >丙二醇 ,而对拉伸强度和弹性模量的影响正好相反 ;相同条件下 ,3种热塑性淀粉塑料的韧性为 :玉米TPS >木薯TPS >小麦TPS。加入经马来酸酐改性后的乙烯 -醋酸乙烯酯共聚物 (EVA)后 ,TPS的韧性显著提高 ,其中 ,以玉米TPS/改性EVA共混物的断裂伸长率最高     

Effect of Attapulgite Clay on Biodegradability and Tensile Properties of Polyvinyl Alcohol/Corn Starch Blend Film

Polyvinyl alcohol (PVOH) with corn starch (CS) at 70/30 weight percent ratio were prepared by a solution casting method with the addition of attapulgite at a range of 0.0–1.0 grams. The aim of this study is to investigate the effect of attapulgite on biodegradability and tensile properties of PVOH/CS matrix. All the results were compared with the control sample (PVOH/CS). The presence of attapulgite had hindered the degradation process in enzymatic, soil, and compost burial. The water sorption content increased with increasing immersion time. The highest tensile strength and elongation at break were shown by the PVOH/CS with 0.2 g of attapulgite content.     

EVA增容改性玉米淀粉／LDPE共混体系的研究

以LDPE和玉米淀粉为主要原料,与EVA熔融共混制备了玉米淀粉／LDPE／EVA共混材料,并对其热学性能和抗张性质进行了研究。DSC分析显示EVA可以明显改善LDPE和淀粉之间的相容性,机械性能也有所改善,在EVA含量为10％时,抗张强度为9．2MPa,断后伸长率为117．4％。     

Effect on thermal,mechanical, and biodegradable properties of plasma-treated fish scale powder/linear low-density polyethylene polymer composite films

In the present work, we report the effect of low-temperature plasma treatment on thermal, mechanical, and biodegradable properties of polymer composite blown films prepared from carp fish scale powder (CFSP) and linear low-density polyethylene (LLDPE). The CFSP was melt compounded with LLDPE using a filament extruder to prepare 1, 2, and 3 wt.% of CFSP in LLDPE polymer composite filaments. These filaments were further pelletized and extruded into blown films. The blown films extruded with 1, 2, and 3 wt.% of CFSP in LLDPE were tested for thermal and mechanical properties. It was observed that the tensile strength decreased with the increased loading content of CFSP, and 1% CFSP/LLDPE exhibited the highest tensile strength. To study the effect of low-temperature plasma treatment, 1% CFSP/LLDP polymer composite with high tensile strength was plasma treated with O₂ and SF₆ gas before blow film extrusion. The 1% CFSP/LLDPE/SF₆-extruded blown films showed increased thermal decomposition, crystallinity, tensile strength, and modulus. This may be due to the effect of crosslinking by the plasma treatment. The maximum thermal decomposition rate, crystallinity %, tensile strength, and modulus obtained for 1% CFSP/LLDPE/SF₆ film were 500.02°C, 35.79, 6.32 MPa, and 0.023 GPa, respectively. Furthermore, the biodegradability study on CFSP/LLDPE films buried in natural soil for 90 days was analyzed using x-ray fluorescence. The study showed an increase in phosphorus and calcium mass percent in the soil. This is due to the decomposition of the hydroxyapatite present in the CFSP/LLDPE biocomposite.     

高温热处理对聚酰亚胺薄膜性能的影响

研究了高温热处理对聚酰亚胺(PI)薄膜拉伸性能和热性能的影响。在薄膜完全环化后,随着热处理温度的升高,薄膜的拉伸强度、弹性模量先增大后基本保持不变,断裂伸长率先保持不变后明显降低,热膨胀系数也显著降低,而薄膜的玻璃化转变温度略有增大。高温热处理工艺可制备高强度和低热膨胀系数的高性能PI薄膜。     

Compression‐molded biocomposite boards from red and white wine grape pomaces

Biocomposite boards from red wine grape pomace (WGP; Pinot Noir) or white WGP (Morio Muscat) were investigated on the basis of crosslinking and thermal compression mechanisms. We used an orthogonal experimental design to optimize the formulations by examining the effects of binder type, pomace‐to‐binder (P/B) ratio, and hydrophobic and crosslinking agents on the mechanical properties, water sensitivity, and biodegradability of the board. The optimized formulations were as follows: (1) for red WGP boards, soy flour (SF) or soy protein isolate (SPI) and poly(vinyl alcohol) (PVA; 1 : 1) as binders at a P/B ratio of 19 : 1 with 1% stearic acid (SA) and 1% epichlorohydrin and (2) for white WGP boards, SF or SPI–PVA (1 : 1) as binders, with a P/B ratio of 4 : 1, and 1% SA. The red WGP boards showed a high break strength and modulus of elasticity with a moderate percentage strain value, whereas the white WGP boards had a high flexibility and biodegradability. After burial in soil for 30 days, the red and white WGP boards degraded by about 50 and 80%, respectively. Microstructure studies indicated that the use of binders and other functional agents resulted in a compact fracture surface of the WGP biocomposite boards. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Crosslinked glutinous rice starch filled polyvinyl alcohol films

The influence of glutinous rice starch (GRS) content and sodium hexametaphosphate (SHMP) in polyvinyl alcohol (PVOH) films were studied. The increase of GRS content (0–40 wt%) reduced the tensile strength (from 14.3 to 4.3 MPa) and elongation at break (from 183 to 52.5) of PVOH/GRS films. Nevertheless, the modulus of elasticity of PVOH/GRS films increased with GRS content, from 20.3 to 132.83 MPa. SHMP was used as a crosslinking agent, which improved more than 30% of tensile strength and modulus of elasticity of PVOH/GRS films. However, the elongation at break reduced after crosslinking process of the films. The crosslinked film showed better interaction between GRS and PVOH, as demonstrated by scanning electron microscopy. Conversely, the crosslinked films exhibited a lower swelling degree, but a higher gel content compared to uncrosslinked films. J. VINYL ADDIT. TECHNOL., 25:359–365, 2019. © 2019 Society of Plastics Engineers     

Mechanical properties and miscibility of polyethersulfone/phenoxy blends

The blends of polyethersulfone and phenoxy were prepared by melt mixing in a Brabenderlike apparatus. The specimens for measurements were made by compression molding and then were water-quenched at room temperature under pressure. The tensile strength, tensile modulus, elongation at break and yield, density, thermal analysis, and dynamic mechanical properties were each measured. The dependence of tensile strength, tensile modulus, elongation at break and yield, and density on composition was obtained. The relationship between tensile modulus and elongation at break and yield and speed of the crosshead at different weight ratios of the blends is shown. The effects of composition and miscibility on the mechanical properties are discussed. © 1996 John Wiley & Sons, Inc.     

可自修复高拉伸硅烷封端聚脲弹性体的研制

以氨基封端聚二甲基硅氧烷、氨基封端聚醚等为原料合成了5种硅烷封端聚脲弹性体(SPUR1～5),采用傅里叶变换红外光谱仪、核磁共振氢谱仪、扫描电子显微镜、热重分析仪、动态热机械分析仪研究了SPUR的结构、热稳定性、拉伸性能、储能模量、损耗模量、自修复性能.结果表明,成功制得了SPUR,SPUR中的氨基封端聚二甲基硅氧烷和...     

Interpenetrating polymer networks from castor oil based polyurethane and poly(methyl methacrylate), III

Liquid prepolyurethanes (PPU) were obtained from castor oil and toluene-2,4-diisocyanate under different experimental conditions varying NCO/OH ratio. All these prepolyurethanes were subsequently interpenetrating with poly(methyl methacrylate) made by radical polymerization initiated with benzoyl peroxide. The novel PPU/PMMA interpenetrating polymer networks were obtained as though films by transfer moulding. They were characterized by thermal studies (DSC and TGA) and mechanical properties viz., tensile strength, modulus of elasticity, and percent elongation at break. The morphological behaviour was analyzed by scanning electron microscopy.     

WRP/SBS热塑性弹性体性能的研究

通过机械共混法制备了废胶粉(WRP)/苯乙烯-丁二烯-苯乙烯(SBS)热塑性弹性体材料,研究了WRP用量及粒径对WRP/SBS加工性能和物理机械性能的影响。研究结果发现,在实验范围内,随着WRP用量的增加,WRP/SBS的流动性、拉伸强度、扯断伸长率、硬度、弹性和压缩永久变形逐渐降低,而300%定伸应力逐渐增大。在WRP用量相同的情况下,加有420μm WRP比加有840μm WRP的WRP/SBS具有较高的拉伸强度、300%定伸应力、硬度和弹性。     

Influence of Radiation‐Induced Grafting Process on Mechanical Properties of ETFE‐Based Membranes for Fuel Cells

The mechanical stability is, in addition to thermal and chemical stability, a primary requirement of polymer electrolyte membranes in fuel cells. In this study, the impact of grafting parameters and preparation steps on stress–strain properties of ETFE‐based proton conducting membranes, prepared by radiation‐induced grafting and subsequent sulphonation, was studied. No significant change in the mechanical properties of the ETFE base film was observed below an irradiation dose of 50 kGy. It was shown that the elongation at break decreases with increasing both the crosslinker concentration and graft level (GL). However, the tensile strength was positively affected by the crosslinker concentration. Yield strength and modulus of elasticity are almost unaffected by the introduction of crosslinker. Interestingly, yield strength and modulus of elasticity increase gradually with GL without noticeable change of the inherent crystallinity of grafted films. The most brittle membranes are obtained via the combination of high GL and crosslinker concentration. The optimised ETFE‐based membrane (GL of ∼25%, 5% DVB v/v), shows mechanical properties superior to those of Nafion® 112 membrane. The obtained results were correlated qualitatively to the other ex situ properties, including crystallinity, thermal properties and water uptake of the grafted membranes.     

玉米芯纤维的结构性能

玉米芯纤维是以从玉米芯中提炼天然有机物时分离出的纤维素残渣作为原材料,以莱赛尔纤维的纺丝技术小试制造出的一种新型纤维素纤维。对这种新纤维的内部结构和性能进行测试分析,发现其强度高于Lenzing公司的黏胶纤维,略低于国产和进口的莱赛尔纤维,有很好的发展应用前景。小试生产的玉米芯纤维的结晶度高于Lenzing公司的黏胶纤维和3家不同企业生产的莱赛尔纤维,取向度也很高,导致其断裂伸长率和标准回潮率低于上述对比纤维;初始模量高于对比纤维,说明进一步试制需要适当降低牵伸倍数,调整工艺,适当提高纤维的柔韧性。