SBS/蒙脱土复合材料的制备及其性能Ⅱ.复合材料的性能

分别采用大分子溶液插层法和大分子熔融插层法制备了苯乙烯-丁二烯-苯乙烯共聚物（SBS）／蒙脱土纳米复合材料．研究了材料的力学性能。纳米结构的形成对复合材料的性能产生显著影响,少量蒙脱士的引入可以明显改善SBS／蒙脱土复合材料的力学性能。无论溶液插层法制备的星型SBS／蒙脱土纳米复合材料,还是熔融插层法制备的线型SBS／蒙脱土纳米复合材料,其拉伸强度和断裂伸长率都同时增加。其中,溶液插层法制备的纳米复合材料的拉伸强度和断裂伸长率分别较纯SBS增加了75％和55％;熔融法制备的纳米复合材料的托伸强度和断裂伸长率分别较纯SBS增加了70％和18％。     

三元乙丙橡胶/蒙脱土纳米复合材料的制备与性能研究

采用熔融插层的方法制备了三元乙丙橡胶(EPDM)／蒙脱土纳米复合材料。X-射线衍射和透射电镜的研究结果表明，该材料的结构为插层型纳米分散结构。研究了蒙脱土用量对该复合材料的力学性能、光学性能和热性能的影响。实验结果表明，该纳米复合材料具有优良的力学性能。当蒙脱土的用量为15份时，该材料的拉伸强度和拉断伸长率分别为19．8MPa和540％。由过氧化物硫化剂2，5-二甲基-2，5-二叔丁基过氧己烷制备的EPDM／蒙脱土纳米复合材料是半透明的，蒙脱土用量对材料的透光率影响较小，蒙脱土用量几乎不影响材料的硫化性能。此外，材料的玻璃化转变温度和热分解温度也由于蒙脱土在基体中的纳米分散和基体与填料相互作用的增强而明显升高。     

凝聚共沉法制备的蒙脱土／天然橡胶纳米复合材料及其性能研究

以新鲜胶乳为主体材料,有机改性蒙脱土为填料,用凝聚共沉法制备了蒙脱土／天然橡胶复合材料,研究了复合材料的物理性能、动态力学性能及其热稳定性。结果表明,在天然橡胶中加入少量（3％-5％）的纳米蒙脱土,可以使橡胶的定伸应力、拉伸强度等性能大幅度提高,动态力学性能和耐热稳定性得到明显改善。     

原位插层聚合PA6／OMMT的性能

以自行合成的NJ-I型插层剂对蒙托土进行改性，并以X射线衍射、傅立叶变换红外光谱及热重分析表征了改性蒙脱土（OMMT）的性能。采用单体熔体插层-原位本体聚合的方法，制备了PA6／OMMT纳米复合材料，测定了该材料的热稳定性能及力学性能。结果表明，含1.2％OMMT的PA6／OMMT纳米复合材料的拉伸强度、弯曲强度及弯曲弹性模量较PA6分别提高14％、16．2％及38.1％，断裂伸长率及冲击强度则分别下降37．7％及4.5％。     

原位插层聚合PA6／OMMT的性能

以自行合成的NJ-l型插层剂对蒙托土进行改性，并以X射线衍射、傅立叶变换红外光谱及热重分析表征了改性蒙脱土（OMMT）的性能。采用单体熔体插层-原位本体聚合的方法，制备了PA6／OMMT纳米复合材料，测定了该材料的热稳定性能及力学性能。结果表明，含1．2％OMMT的PAG／OMMT纳米复合材料的拉伸强度、弯曲强度及弯曲弹性模量较PA6分别提高14％、16．2％及38．1％，断裂伸长率及冲击强度则分别。下降37．7％及4．5％。     

聚丙烯-蒙脱土纳米复合材料性能的研究

采用熔融插层法制备了聚丙烯-蒙脱土纳米复合材料,并对复合材料的力学性能及晶形结构进行研究.结果表明:添加少量的纳米蒙脱土(<5%,质量分数),能够明显改善PP/MMT纳米复合材料的力学性能,当其质量分数达到4%～5%时,复合材料的冲击强度、断裂伸长率、拉伸强度及弹性模量均达最佳值.同时,随着蒙脱土含量的增加,聚丙烯的晶形结构会发生转变,其晶体尺寸呈不断减小趋势.     

高密度聚乙烯／蒙脱土纳米复合材料的制备与性能研究

采用马来酸酐接枝乙烯醋酸乙烯酯（EVA-g-MAH）和马来酸酐接枝低密度聚乙烯（PE-LD-g-MAH）为相容剂，制备了高密度聚乙烯傣脱土（PE-HD／MMT）纳米复合材料。用X射线衍射和扫描电镜对有机蒙脱土和PE-HD／MMT复合材料的结构进行了表征，研究了蒙脱土和相容剂含量对制备的纳米复合材料力学性能及热性能的影响。结果表明，相容剂的加入有利于插层。MMT在复合材料中呈纳米级分散。其层间距可由2．10nm增大至3．85nm。MMT含量为3％（质量分数，下同）、EVA-g-MAH含量为15％时，复合材料的综合力学性能最好，冲击强度和拉伸强度分别较PE-HD提高43．7％和5.8％。     

纳米蒙脱土-脂肪族聚氨酯弹性体的合成与制备

采用聚四氢呋喃醚（PTMG1000）为软段,4,4’-二环己基甲烷二异氰酸酯（HMD1）、异佛尔酮二异氰酸酯（1PD1）为硬段,层间距分别为1．95nm和2．40nm的2种有机蒙脱土,以插层聚合法制备出不同硬段含量和有机蒙脱土含量的纳米蒙脱土．脂肪族聚氨酯弹性体,并研究了硬段含量、有机蒙脱土含量、二异氰酸酯和有机蒙脱土种类对脂肪族聚氨酯弹性体力学性能的影响。结果表明,硬段含量对材料力学性能影响最大,其次是有机蒙脱土含量。当硬段质量分数达40％时,拉伸强度最高达14．06MPa;有机蒙脱土少量加入可有效提高材料的撕裂强度和断裂伸长率。以HMD1、PTMG1000和MMT2为原料,硬段质量分数为40％时,所合成的纳米蒙脱土-脂肪族聚氨酯弹性体具有较好的力学性能。     

含有纳米蒙脱土的HIPS的制备与性能研究

究含纳米蒙脱土的高抗冲聚苯乙烯(HIPS)的制备工艺,测试了试样的冲击强度和拉伸强度等力学性能,观察了试样冲击断面的结构形态。结果表明,在PS中加入少量蒙脱土和橡胶弹性体制备的HIPS冲击强度为16．2kJ／m^2,拉伸强度为46．6MPa,断裂伸长率为1．62％,已接近或达到工程塑料的使用要求。原因是纳米蒙脱土粒子在橡胶微粒界面上富集,使两者产生了协同改性效应。     

交联聚乙烯/丙烯酸/蒙脱土纳米复合材料的制备与表征

在制备交联聚乙烯／蒙脱土纳米复合材料的过程中,利用交联聚乙烯的特征,通过在与蒙脱土熔融复合的过程中加入单体丙烯酸作为相容剂,制得交联聚乙烯／蒙脱土纳米复合材料。用XRD、TEM进行表征,并对材料的力学性能进行测试。结果显示：复合材料的拉伸强度与原基材相比有所上升,而冲击强度有所下降。     

聚氨酯/纳米金刚石纳米复合材料的性能研究

通过原位反应法制备了聚氨酯(PU)/纳米金刚石(ND)纳米复合材料,采用X射线衍射(XRD)、热失重分析(TGA)、扫描电子显微镜(SEM)和力学性能测试等手段系统研究了PU/ND纳米复合材料的力学性能、热性能和形态。研究结果表明,ND能够显著提高聚氨酯的力学性能。随着ND用量的增加,PU/ND纳米复合材料的拉伸强度、100%定伸应力、500%定伸应力和断裂伸长率先增加后减少。当ND质量分数为0.5%时,PU/ND纳米复合材料的力学性能最佳,拉伸强度和断裂伸长率分别提高了61.5%和39.1%。PU/ND纳米复合材料的T-剥离强度和耐热性也有提高。     

Effects of thermoplastic poly(ether-ester) elastomer and bentonite nanoclay on properties of poly(lactic acid)

This work presented the influence of thermoplastic poly(ether-ester) elastomer (TPEE) and bentonite (BTN) on improving the mechanical and thermal properties of poly(lactic acid) (PLA). PLA was initially melt mixed with TPEE at six different loadings (5–30 wt%) on a twin screw extruder and then injection molded. The mechanical tests revealed an increasing impact strength and elongation at break with increasing TPEE loading, but a diminishing Young's modulus and tensile strength with respect to pure PLA. The blend at 30 wt% TPEE provided the optimum improvement in toughness, exhibiting an increase in the impact strength and elongation at break by 3.21- and 10.62-fold over those of the pure PLA, respectively. Scanning electron microscopy analysis illustrated a ductile fractured surface of the blends with the small dispersed TPEE domains in PLA matrix, indicating their immiscibility. The 70/30 (wt/wt) PLA/TPEE blend was subsequently filled with three loadings of BTN (1, 3, and 5 parts by weight per hundred of blend resin [phr]), where the impact strength, Young's modulus, tensile strength and thermal stability of all the blends were improved, while the elongation at break was deteriorated. Among the three nanocomposites, that with 1 phr BTN formed exfoliated structure and so exhibited the highest impact strength, elongation at break, and tensile strength compared to the other intercalated nanocomposites. Moreover, the addition of BTN was found to increase the thermal stability of the neat PLA/TPEE blend due to the barrier properties and high thermal stability of BTN.     

插层剂对尼龙6/蒙脱土纳米复合材料性能的影响

用3种不同的插层剂有机化蒙脱土,并分别与尼龙6熔融共混制得了尼龙6/蒙脱土纳米复合材料,对热变形温度(HDT)和力学性能进行了研究。结果表明:与纯尼龙6相比,3种复合材料的HDT、拉伸模量、弯曲模量、弯曲强度有明显提高,屈服强度也有所提高,而冲击强度和断裂伸长率则有所下降;其中,含羟基的插层剂对复合材料的综合改性效果最好。     

熔融插层法制备聚丙烯／粘土复合材料及性能研究-I增容剂对聚丙烯／粘土复合材料力学性能的影响

通过添加不同含量的粘土制备了三个不同类型（PP／DK1,PP／PPMA／DK1,PP／PPMA＋DK1）纳米粘七／聚丙烯复合材料。使用力学性能测试对实验样品进行力学性能分析,结果表明：相对于纯聚丙烯,复合材料的拉伸强度、断裂伸长率随着粘土含量的增加呈先增加后下降趋势;而随着PPMA量的增加,基体的总体性能都呈现下降的趋势。     

MC尼龙／Sm2O3纳米复合材料的制备及性能研究

用原位分散聚合法制备了一系列MC尼龙/Sm2O3纳米复合材料,并对其结构和力学性能进行了表征.结果表明,纳米Sm2O3使MC尼龙晶格尺寸发生了一定程度的改变;纳米Sm2O3的加入可以明显改善MC尼龙的力学性能,对MC尼龙同时具有增强和增韧双重效果;MC尼龙/Sm2O3纳米复合材料的力学性能随着纳米Sm2O3用量的增加呈先升高后降低的趋势.当纳米Sm2O3的质量分数为0.5%时,复合材料的拉伸强度和断裂伸长率达到最大值,分别比MC尼龙提高了18.8%和91.5%,当纳米Sm2O3的质量分数为1.0%时,复合材料的缺口冲击强度、穹曲强度和弯曲弹性模量达到最大值,分别比MC尼龙基体提高了36.6%、11.2%和11.5%.     

Preparation and characterisation of hydroxyl-terminated polybutadiene-based polyurethane/graphene nanocomposites

Polyurethane nanocomposites based on hydroxyl-terminated polybutadiene and graphene with different formulations were cured using toluene diisocyanates. The rheological, physical, mechanical, thermal and morphological properties of the nanocomposites were investigated. The viscosity of the samples increased rapidly with graphene content. However, the kinetic rate of the curing process was lower for the nanocomposites in comparison to the neat matrix. The mechanical properties showed a successive increase in the tensile strength and reduction in elongation at break with an increase in graphene content. The highest value of the modulus, density and degradation temperature was obtained for the nanocomposite with 1?wt-% graphene. The hardness properties of the nanocomposites enhanced with curing time. The morphological properties of the nanocomposites are also investigated with the field emission scanning electron microscopy which confirmed the agglomeration occurrence at the high graphene contents.     

Effect of replacement of castor oil and polychloroprene by chlorinated paraffin in butyl compounds of tyre‐curing bladder

Ways are explored to increase the life and to reduce the cost of tyre‐curing bladders by improving their mechanical and ageing properties. Nine formulations have been designed which involve the partial replacement of polychloroprene (PC) and castor oil (CO), both individually and simultaneously, by chlorinated paraffin (CP) in the butyl bladder compound. The compounds have been tested for various cure properties such as initial torque, minimum torque, scorch time, optimum cure time, cure rate, maximum torque and reversion time. The vulcanized samples have been tested for mechanical properties such as tensile stress at 300 % elongation, tensile strength at break, ultimate elongation, rubber deterioration by dynamic fatigue test and Shore‐A hardness before and after ageing. The results show that tensile strength at break and ultimate elongation decrease, while tensile stress at 300 % elongation increase except in one case (when PC was partially replaced by CP). Simultaneous and individual replacement of CO by CP results in a decrease in hardness of up to 3 phr (base recipe CO 5 phr), whereas further replacement of CO by CP results in an increase in hardness. Tensile stress at 300 % elongation and Shore‐A hardness increase up to a limit while tensile strength at break and ultimate elongation decrease with ageing. © 2000 Society of Chemical Industry     

Influence of processing condition and carbon nanotube on mechanical properties of injection molded multi‐walled carbon nanotube/poly(methyl methacrylate) nanocomposites

In this work, multi‐walled carbon nanotubes (MWCNT) and poly(methyl methacrylate) (PMMA) pellets were compounded via corotating twin‐screw extruder. The produced MWCNT/PMMA nanocomposite pellets were injection molded. The effect of MWCNT concentration, injection melt temperature and holding pressure on mechanical properties of the nanocomposites were investigated. To examine the mechanical properties of the MWCNT/PMMA nanocomposites, tensile test, charpy impact test, and Rockwell hardness are considered as the outputs. Design of experiments (DoE) is done by full factorial method. The morphology of the nanocomposites was performed using scanning electron microscopy (SEM). The results revealed when MWCNT concentration are increased from 0 to 1.5 wt %, tensile strength and elongation at break were reduced about 30 and 40%, respectively, but a slight increase in hardness was observed. In addition, highest impact strength belongs to the nanocomposite with 1 wt % MWCNT. This study also shows that processing condition significantly influence on mechanical behavior of the injection molded nanocomposite. In maximum holding pressure (100 bar), the nanocomposites show highest tensile strength, elongation, impact strength and hardness. According to findings, melt temperature has a trifle effect on elongation, but it has a remarkable influence on tensile strength. In the case of impact strength, higher melt temperature is favorable. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43738.     

Effect of nanocrystalline cellulose on morphological,thermal, and mechanical properties of Nylon 6 composites

In this study, nanocomposites based on Nylon 6 and nanocrystalline cellulose (NCC) were prepared by melt compounding. Then, morphological, thermal, and mechanical properties were analyzed for NCC content between 0 and 7 wt%. Morphological analyses showed different roughness in fractured surface of neat Nylon and its nanocomposites caused by the presence of NCC. Mechanical results showed that the optimum properties were obtained at 3% NCC which could be related to relatively good NCC dispersion at low concentrations with good Nylon‐NCC bonding. Overall, flexural (41%) and tensile (23%) moduli, as well as tensile strength (11%) were increased up to 3% of NCC. However, elongation at break and impact strength decreased with NCC addition. Finally, density and hardness showed only a small increase of 5 and 3%, respectively. POLYM. COMPOS., 37:1473–1479, 2016. © 2014 Society of Plastics Engineers