Studies of the Physico-Mechanical,Interfacial, and Degradation Properties of Jute Fabrics/Melamine Composites

Jute fabrics/melamine composites (20% fiber) were prepared by compression molding. Mechanical properties of the composites were evaluated. Mechanical properties of starch-treated jute/melamine composites, including tensile strength (31%), bending strength (29%), tensile modulus (23%), bending modulus (25%), impact strength (113%), and hardness (4%), inproved significantly over the untreated composite. Fracture surfaces of untreated and treated composites were studied by scanning electron microscopy (SEM) and supported poorer fiber matrix adhesion for the untreated composite than that of the treated composite. Water uptake and soil degradation tests of untreated and treated composites were also performed.     

Comparative Studies on the Mechanical,Degradation and Interfacial Properties between Jute and E-Glass Fiber-Reinforced PET Composites

Jute fiber mat (hessian cloth) reinforced PET-based composites (50% fiber by weight) and E-glass fiber matreinforced PET based composites (50% fiber by weight) were fabricated by compression molding and the mechanical properties tensile strength (TS), tensile modulus (TM), elongation at break (%), bending strength (BS), bending modulus (BM), impact strength (IS) and hardness (Shore-A) of the composites were evaluated and compared. The interfacial properties of the both composites were also compared. Water uptake test and soil degradation test were also investigated.     

Physico-Mechanical,Interfacial, Degradation,and Dielectric Properties of Jute/PP Composites: Effect of Dye and Gamma Radiation

Jute fabrics/polypropylene composites were prepared by compression molding. Jute fabrics were treated with red dye solutions (0.1–1%, w/w) for different soaking times and we found that 0.5% red-dye-treated jute/PP composite for 5 min soaking time showed better results. Gamma radiation (250-1000 krad dose) was applied on both jute and matrices. Composites were fabricated with non-irradiated jute/non-irradiated PP (C-0), non-irradiated jute/irradiated PP (C-1), irradiated jute/non-irradiated PP (C-2), and irradiated jute/irradiated PP (C-3). It was found that a C-3 composite made using 500 krad dose showed the best results. Simulating weathering and dielectric properties of the composites were also performed.     

Fabrication and Mechanical Characterization of Jute Fabrics: Reinforced Polyvinyl Chloride/Polypropylene Hybrid Composites

Jute fabrics such as reinforced polyvinyl chloride (PVC), polypropylene (PP), and a mixture of PVC and PP matrices-based composites (50 wt% fiber) were prepared by compression molding. Tensile strength (TS), bending strength (BS), tensile modulus (TM), and vbending modulus (BM) of jute fabrics' reinforced PVC composite (50 wt% fiber) were found to be 45 MPa, 52 MPa, 0.8 GPa, and 1.1 GPa, respectively. The effect of incorporation of PP on the mechanical properties of jute fabrics' reinforced PVC composites was studied. It was found that the mixture of 60% PP and 40% PVC matrices based composite showed the best performance. TS, BS, TM, and BM for this composite were found to be 65 MPa, 70 MPa, 1.42 GPa, and 1.8 GPa, respectively. Degradation tests of the composites for up to six months were performed in a soil medium. Thermo-mechanical properties of the composites were also studied.     

环氧化天然橡胶复合材料性能研究

采用新方法制备环氧化天然橡胶(ENR)/白炭黑和天然橡胶(NR)/ENR/白炭黑复合材料,并对其性能进行研究。结果表明:ENR/白炭黑复合材料的热稳定性优于ENR;在NR/ENR并用胶中加入白炭黑和硅烷偶联剂KH-550,NR/ENR/白炭黑复合材料0℃时的损耗因子(tanδ)增大,65℃时的tanδ值减小,复合材料的抗湿滑性能提高,滚动阻力减小。     

天然橡胶复合材料制备及力学性能研究

分别以白炭黑、碳纳米管、碳微球及石墨烯为增强剂,对天然橡胶复合材料的制备以及其力学性能进行研究。采用传统机械混炼法将复合材料进行混合,通过平板硫化机进行交联制备天然橡胶复合材料。分别考察不同增强剂的含量对橡胶复合材料力学性能的影响,找到最佳的添加量。分析了不同种增强剂对复合材料力学性能的影响规律,对其增强效果进行对比说明。采用电子万能拉伸测试仪、邵氏硬度计对复合材料的拉伸性能和硬度性能进行分析,结果表明:复合材料的力学性能随着炭微球、碳纳米管和石墨烯含量的增加而增加,随着白炭黑的含量的增加而减少,碳纳米管和石墨烯的增强效果较好。     

Comparative Studies of Mechanical and Interfacial Properties Between Jute Fiber/PVC and E-Glass Fiber/PVC Composites

Composites (50 wt% fiber) of jute fiber reinforced polyvinyl chloride (PVC) matrix and E-glass fiber reinforced PVC matrix were prepared by compression molding. Mechanical properties such as tensile strength (TS), tensile modulus (TM), bending strength (BS), bending modulus (BM) and impact strength (IS) of both types of composites was evaluated and compared. Values of TS, TM, BS, BM and IS of jute fiber/PVC composites were found to be 45 MPa, 802 MPa, 46 MPa, 850 MPa and 24 kJ/m², respectively. It was observed that TS, TM, BS, BM and IS of E-glass fiber/PVC composites were found to increase by 44, 80, 47, 92 and 37.5%, respectively. Thermal properties of the composites were also carried out, which revealed that thermal stability of E-glass fiber/PVC system was higher. The interfacial adhesion between the fibers (jute and E-glass) and matrix was studied by means of critical fiber length and interfacial shear strength that were measured by single fiber fragmentation test. Fracture sides after flexural testing of both types of the composites were investigated by Scanning Electron Microscopy.     

低温硫化NR/BR并用胶的硫化特性及其力学性能研究

采用异丙基黄原酸钠SIP、N-乙基-N-苯基二硫代氨基甲酸PX的复合促进剂体系(用量分别为1.5phhr和0.5phhr)可使天然橡胶/顺丁橡胶并用胶(并用比为70∶30)在90℃~95℃内快速硫化,硫化特性符合缓冲胶工艺的要求,但其性能与HG/T 4124-2009《预硫化缓冲胶》存在一定的差距。     

Effects of Rice Husk Filler on the Mechanical and Thermal Properties of Liquid Natural Rubber Compatibilized High-Density Polyethylene/Natural Rubber Blends

Natural rubber/high-density polyethylene (NR/HDPE) blend with rice husk (RH) filler and liquid natural rubber (LNR) as the compatibilizer was prepared using an internal mixer at 140°C and 50 rpm. The reinforcing effect and compatibilizing performance of the added reagents in the composites were evaluated from the mechanical and thermal properties, and blend homogeneity. The tensile and impact strength decreased with RH loadings in the matrix, while the tensile modulus and hardness showed an opposite trend. The weak filler–matrix interaction, resulting in poor filler dispersion and large agglomerated particle size, caused those properties to decrease. However, the mechanical properties of the composites improved with the addition of NR or LNR into the matrix. The dissolution effect caused interactions between the phases, leading to an improvement in the compatibility in the blend. Changes in morphology resulted in the shift of T _g of the amorphous part of NR to higher temperatures, as observed in differential mechanical analysis (DMA) thermograms. Scanning electron microscopy (SEM) micrographs of the fractured surface had also revealed the good RH–matrix interaction and, thus, the dispersion of particles in samples with added LNR.     

LLDPE/纳米ZnO复合材料的制备与性能研究

将改性纳米ZnO与线型低密度聚乙烯(LLDPE)熔融共混、制备了LLDPE/纳米ZnO复合材料。通过SEM观察纳米ZnO粒子在LLDPE基体中的分散情况;研究了复合材料的力学性能及维卡软化点。结果表明:改性纳米ZnO的加入可提高LLDPE的力学性能和维卡软化点。其中,复合材料的拉伸强度、断裂伸长率、冲击强度、弯曲强度的最大值分别比LLDPE提高了17.00%、13.42%、9.90%、7.04%。     

茶多酚改性天然胶乳复合材料的制备及性能研究

以多羟基结构的茶多酚作界面改性剂,制备了埃洛石纳米管/天然胶乳复合材料及二氧化硅/天然胶乳复合材料,研究了茶多酚对复合材料界面作用及力学性能的影响。结果表明,茶多酚分别能与埃洛石纳米管和二氧化硅形成氢键,改善了填料与橡胶基体间的界面作用。茶多酚改性天然胶乳复合材料的力学性能显著提高,其原因归因于复合材料界面状态的改善。     

凝固方法对天然橡胶力学性能的影响

研究了三种不同凝固方法对天然橡胶性能和炭黑/天然橡胶硫化胶力学性能的影响。结果表明,采用十二烷基硫酸钠和氯化钙凝固制得的天然橡胶达到5号标准橡胶的质量,其力学性能比用醋酸凝固所制得的天然橡胶的力学性能要好。     

LLDPE/纳米ZnO复合材料熔体流变性的研究

将纳米ZnO(或改性纳米ZnO)与LLDPE经Brabender挤出机熔融共混制备了LLDPE/纳米ZnO复合材料,采用毛细管流变仪和HAAKE转矩流变仪研究了该复合材料的熔体流变性能,讨论了纳米ZnO、改性纳米ZnO及KH550偶联剂含量对LLDPE熔体流变性能的影响。结果表明:少量纳米ZnO的加入略提高了LLDPE的表观黏度、黏流活化能和熔体的平衡转矩,改性纳米ZnO复合材料的表观黏度比未改性纳米ZnO复合材料的略低。     

顺丁橡胶/环氧树脂橡塑复合材料的制备及性能研究

采用机械共混制得顺丁橡胶(BR)/双酚A型环氧树脂(E-44)两网型橡塑复合材料。考察了橡胶硫化体系与环氧树脂固化体系的相互影响及环氧树脂比例对顺丁橡胶/环氧树脂复合材料结构及力学性能的影响。结果表明:橡胶硫化体系加速了环氧树脂的固化。SEM与DSC分析结果表明顺丁橡胶与环氧树脂形成了两网结构。随着环氧树脂比例的增加,拉伸强度、撕裂强度、100%定伸应力、硬度逐渐增强,扯断伸长率逐渐下降。     

稀土异戊橡胶与天然橡胶共混胶性能的研究

对不同共混比的稀土异戊橡胶（NdIR）/天然橡胶（NR）共混胶的硫化特性及物理机械性能进行了系统研究,并与俄罗斯钛体系异戊橡胶（SK-3）及SK-3/NR共混胶的性能进行了对比。结果表明,NdIR/NR的相容性好于SK-3/NR;NdIR/NR共混胶较好地保持了NR原有的高拉伸、高抗撕裂性能,并能有效提高交联密度和拉断伸长率,其焦烧时间得到适当延长;NdIR/NR共混胶没有出现炭黑团聚和微相分离现象,NdIR在某些领域可替代天然橡胶。     

Preparation and Properties of Natural Rubber/Palygorskite Composites by Co-Coagulating Rubber Latex and Clay Aqueous Suspension

Natural rubber (NR)/Palygorskite composites were prepared by co-coagulating rubber latex and clay aqueous suspension. Org-palygorskite was attained by using cetyltrimethylammonium bromide (CTAB) and the four factors influencing the average diameter of palygorskite were discussed. Four optimal conditions of preparing minimum average diameter were determined which included the concentration of palygorskite, the concentration of sodium polyacrylate, ultrasonic time and ultrasonic power. Mechanical properties suggested that composites using modified palygorskite which were dispersed by ultrasonic wave were the best, the tensile strength, tear strength, 300% modulus and shall hardness increased by 77.14%, 118.18%, 242.86% and 65.2%, respectively. Modified palygorskite was shown by FTIR spectrogram and observed by ESEM. Modified palygorskite dispersed by ultrasonic wave were dispersed into the rubble uniformly, some stick particles inserted into the rubber and it is difficult to find stick shape, and there were 20% particles belonging to nanomaterials and 80% micromaterials.     

蒙脱土/硅橡胶复合材料的力学和阻燃性能研究

采用熔融共混法制备了蒙脱土/硅橡胶硅橡胶,研究了蒙脱土对硅橡胶力学和阻燃性能的影响.结果表明,有机改性利于蒙脱土在硅橡胶中的分散,并提高硅橡胶的拉伸强度和阻燃性能;随着蒙脱土用量的增加,硅橡胶的拉伸强度和扯断伸长率均先增后减,氧指数先是剧增后缓增;当层间距d001为3.4 nm的有机改性蒙脱土的质量分数为6%时,硅橡胶的拉伸强度达到12.1 MPa,扯断伸长率为362%,氧指数为32.7%,硅橡胶的起始分解温度和终止分解温度分别比空白样提高83℃和13℃.     

Synergism Effect of Montmorillonite and Cellulose Whiskers on the Mechanical and Barrier Properties of Natural Rubber Composites

A series of nanocomposite films based on natural rubber (NR), Na⁺‐montmorillonite (MMT), and cellulose whiskers (W) was prepared, keeping a total filler content equal to 5 wt.‐%. In the binary NR/MMT system, small stacks of intercalated montmorillonites were homogeneously dispersed within the polymer matrix whereas they were clearly lying in the vicinity of cellulose whiskers in the ternary NR/MMT/W blends. The effects of MMT and W on mechanical and gas barrier properties of the nanocomposite films were investigated. A significant increase of the rubbery modulus was obtained upon filler addition. The reinforcing effect was particularly important for the nanocomposite film reinforced with 1 wt.‐% MMT and 4 wt.‐% W. The improvement of the gas barrier properties observed upon filler addition was explained by a tortuosity effect. The calculated tortuosity values indicated that the simultaneous use of MMT and W could greatly slow down the gas diffusion rate in NR. Formation of MMT‐W subassembly should be responsible for this synergism effect.

     

天然橡胶的疲劳特性研究进展

叙述了天然橡胶的疲劳特性，着重归纳了天然橡胶的破坏机理及影响其疲劳破坏的主要因素。