NBR/ORGANOMODIFIED BENTONITE INTERCALATED HYBRIDS AND THEIR EFFECTS ON THE TOUGHNESS OF PVC

Hybrids of intercalative nitrile-butadiene rubber/organomodified bentonite (NBR/OMB) were prepared by thelatex intercalation technique. Investigation of their mechanical properties and the microstructore of NBR/OMB showed thatthe organomodified bentonite is an effective toughener for NBR. Transmission electronic microscopy (TEM) and X-rnydiffraction (XRD) tests showed that the NBR macromolecule could be intercalated into the galleries of bentonite.Incorporation of NBR/OMB hybrids as tougheners into poly(vinyl chloride) (PVC) results in a substantial increase in theimpact strength of PVC, but little decrease in its tensile strength and flexural strength, compared to the unmodified PVC.     

MMA接枝改性PVC/CaCO3纳米复合材料的力学性能

采用熔融共混法制备PMMA接枝改性纳米CaCO3增韧PVC（PVC/CaCO3）复合材料,并研究了复合材料的力学性能.结果表明,通过表面PMMA的接枝改性,可以显著提高纳米CaCO3增韧聚氯乙烯复合材料的拉伸强度和拉伸模量,在纳米CaCO3颗粒表面PMMA包覆层厚度为2nm时,复合材料的拉伸强度和拉伸模量达到极大值.对比于未处理纳米CaCO3和钛酸酯偶联剂处理纳米CaCO3,PMMA接枝改性纳米CaCO3增韧PVC复合材料的拉伸强度得到较大幅度提高.SEM显示,经过PMMA接枝改性后的碳酸钙在PVC基体中分散均匀,与基体界面结合良好.     

SBA/PVC复合树脂的制备与表征

采用聚丙烯酸正丁酯(PBA)改性的丁苯(SBR)胶乳为种子乳液(SBA),通过乳液接枝共聚氯乙烯制备了SBA/PVC复合树脂.通过粒径分析仪、动态力学分析仪(DMA)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等测试手段,表征了复合胶乳粒的粒径与形态,以及材料的形态结构.粒径分析表明PVC确实包覆在SBA上;TEM研究结果显示SBA/PVC胶乳粒子呈现明显的核壳结构,PBA加入可提高SBR在复合材料中的分散性;DMA分析表明SBA/PVC复合树脂在低温区呈现了一个宽而弱的转变峰,揭示了接枝过渡层的微观结构特征;研究了交联剂和PBA用量对材料性能的影响,结果表明在PBA含量较低时,SBA/PVC复合树脂就显示了优良的冲击性能,且SEM照片显示材料断面形貌为特征性韧性断裂.     

无水AlCl_3催化PVC/PS反应性增容的研究

以无水AlCl3为催化剂,通过聚氯乙烯(PVC)与聚苯乙烯(PS)之间Friedel-Crafts反应,实现了PVC/PS共混体系的反应性增容,使PVC与PS熔融共混温度由160℃降为140℃;通过预碾磨和加入苯乙烯(St)的方法,提高材料韧性,制备了综合力学性能良好的PVC/PS合金材料.应用FTIR、DSC、SEM和力学性能测试等手段表征了合金材料的结构与性能.结果表明,FTIR出现了1943和838 cm-12个苯环对位被取代的特征吸收峰;DSC在89℃出现了玻璃化转变;SEM证明PVC/PS两相界面粘接性随AlCl3、St的加入越来越好.在PS、AlCl3和St的质量分数分别为6%,0.6%和9%时,实现了对PVC的增强增韧.合金拉伸强度达到60.54MPa,比PVC的49.35 MPa提高了22.7%;缺口冲击强度达到5.3 kJ/m2,比PVC的3.9 kJ/m2提高了35.9%.     

ACR-g-PVC复合粒子结构与对PVC的增韧效率

采用丙烯酸丁酯 (BA)和丙烯酸 2 乙基己酯 (EHA)交联共聚物为核 ,BA与EHA或甲基丙烯酸甲酯(MMA)与苯乙烯 (St)或MMA与丙烯酸乙酯 (EA)交联共聚物为壳 ,合成了 3种聚丙烯酸酯 (ACR) [P(BA EHA)、ACRⅠ、ACRⅡ ]胶乳 .以 3种ACR胶乳为种子 ,分别与氯乙烯 (VC)进行乳液接枝共聚 ,制备了相应 3种复合粒子 (ACR g PVC) .借助动态光散射法和透射电镜考察了ACR与复合乳胶粒的粒径与结构 ,表征了所研制材料的形态和冲击韧性 .研究结果表明 ,3种ACR g PVC材料的常温缺口冲击强度随ACR含量增加而显著提高 ,其突跃点的发生具有等橡胶量效应 ,其临界橡胶含量约为 4 % ,并采用脆 韧转变的临界粒子间距模型对其进行了解释 ;P(BA EHA)比核 壳ACRⅠ或ACRⅡ具有更高的增韧效率 ,依据复合粒子的两种理想结构模型对其增韧效率进行了分析 .     

Zn/Al层状双氢氧化物-聚氯乙烯纳米复合物的制备与性能

用共沉淀法制备油酸钾改性的Zn2+、Al 3+层状双氢氧化物(Zn/Al-LDH),以环己酮为溶剂,用溶液插层法制备了Zn/Al层状双氢氧化物-聚氯乙烯(PVC)纳米复合物。采用傅里叶红外(FT-IR)、X-射线衍射(XRD)、透射电镜(TEM)对复合材料的结构及形貌进行了表征,并用热分析仪、万能试验机和紫外分光光度计研究了复合物的热稳定性能、拉伸性能和紫外吸收性能。结果表明:Zn/Al-LDH纳米片层无序分散在PVC基体中;Zn/Al-LDH对PVC低温时的骨干脱氯化氢有促进作用;与PVC膜相比,复合膜的分解温度降低,高温碳化温度升高,复合膜的拉伸强度及断裂伸长率得到提高,在300~380nm具有一定的紫外吸收性能。     

P(BA-EHA)/PVC复合胶乳的制备及表征

采用乳液聚合法合成了丙烯酸丁酯与丙烯酸 2 乙基己酯交联共聚物 [P(BA EHA) ]乳液 ,以P(BA EHA)乳液为种子通过与氯乙烯 (VC)聚合制备了P(BA EHA) PVC复合胶乳 .考察了P(BA EHA)乳液用量对复合胶乳粒径及其材料力学性能的影响 ,借助透射电镜 (TEM)、扫描电镜 (SEM)和动态力学分析 (DMA)等手段对复合胶乳粒子及其所制材料的形态结构进行了表征 .DMA研究结果表明 ,橡胶相P(BA EHA)与基体PVC间相容性得到了良好改善 .随着P(BA EHA)含量的增加 ,低温区材料的力学损耗峰较纯聚氯乙烯增强 ,且峰位逐渐向高温区移动 .TEM照片显示 ,复合胶乳粒子具有清晰的核壳结构 ;P(BA EHA)非常均匀地分散在PVC中 ,两相界面模糊 .由SEM照片可见 ,材料缺口断面表现为很好的韧性断裂 .含 4 2 %P(BA EHA)材料的缺口抗冲强度是PVC的 11倍 ,断裂伸长率较PVC提高近两倍 .     

含磷聚芳醚酮颗粒层间增韧碳纤维/双马树脂RTM复合材料

选用一种在RTM双马来酰亚胺树脂(BMI)注射温度下不溶解的含磷聚芳醚酮(P-PAEK)热塑性树脂作为增韧剂,制备层间颗粒增韧碳纤维增强双马来酰亚胺树脂基复合材料.研究了不同热塑树脂含量对树脂浇铸体冲击性能的影响,利用扫描电镜表征了复相体系的微观形貌并分析其增韧机制,并通过层间断裂韧性测试表征了RTM双马树脂基复合材料增韧前后的层间韧性性能.结果表明,当附载热塑颗粒面密度为2 g/m2时,复合材料的I型层间断裂韧性(GIC)为0.54 k J/m2,II型层间断裂韧性(G_(IIC))为1.36 k J/m~2,较未增韧复合材料分别提升约56%和42%.增韧后的复合材料在保持原有力学性能的同时,其冲击后压缩强度(CAI)提升约29%,层间剪切强度达到111.7 MPa.     

PVC/MBS/纳米 BaSO4 复合材料的制备及其性能

采用熔融共混法制备聚氯乙烯(PVC)/甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS)/纳米重晶石(nano-BaSO4)三元复合材料,考察其力学性能和热稳定性能,并用扫描电镜观察冲击断面的形态.结果表明:MBS 与 nano-BaSO4 可协同增韧 PVC;当 MBS、nano-BaSO4 的含量分别为 10%、1%时,材料的韧性和刚性可同时得以改善,其冲击断面表现出典型的韧性断裂特征;热重分析显示添加 1%nano-BaSO4 可显著提高 PVC/MBS 的热稳定性能,其第一降解阶段的初始分解温度和最快分解温度分别提高了 10℃和14℃.     

苎麻纤维布和碳纤维布混杂铺层复合材料力学和阻尼性能研究

将具有优异阻尼减振性能的纯天然苎麻纤维布与力学性能较好的碳纤维布混杂铺层,利用VRAM(真空吸注成型)工艺制备了环氧树脂基结构阻尼复合材料.首先考察了复合材料的力学性能,包括动态力学性能、静态力学性能和冲击断裂韧性;其次通过共振频率和阻尼因子评价了复合材料的阻尼减振性能.结果表明,通过苎麻纤维布/碳纤维布的混杂铺层能够平衡力学性能和阻尼性能之间的矛盾,可根据实际应用需求实现材料阻尼性能和力学性能的可控调节,充分发挥复合材料可设计性强的优势.其中"RCRCR"型铺层复合材料的损耗因子达到0.0057,比纯碳纤维布复合材料的0.0018提高了2.2倍,而拉伸强度和拉伸模量分别达到381.6 MPa和21.5 GPa,比纯苎麻纤维板提高了4.6倍和97.2%.最后,对混杂铺层复合材料的结构进行分析并针对阻尼性能进行有限元模拟,探讨了不同铺层方式影响复合材料力学性能和阻尼性能的规律,并对其他混杂铺层的复合材料的共振频率和损耗因子进行预测,为结构阻尼材料的设计提供一定的参考依据.     

TG-MS analysis of nitrile butadiene rubber blends (NBR/PVC)

Blends of nitrile butadiene rubber (NBR) with polyvinyl chloride (PVC) are widely used in products such as hoses and seals. As part of a project that uses NBR/PVC blends for manufacturing forest fire hoses, blends of NBR/PVC with various inorganic fillers, such as Mg(OH)₂, china clay (organic modified kaolin) and nano clay (organic modified bentonite) were studied by TG-MS. No significant changes were observed to the type of the polymers’ decomposition products, compared to that of NBR/PVC blend without additives. The most remarkable change was the absence of HCl from decomposition products in the presence of the Mg(OH)₂ additive.     

Synthesis and Structure Control of A New Kind of Inelastomer Impact Modifier with Core-shell Structure and Impact Modification to PVC/CPE

Introduction　　 As a structure material,a polymer has two important mechanical properties,i.e.,strength and toughing.Therefore,plastic toughening isalwaysa fundamental study on poly-mer materials.Traditionally,toughnessmodification isto make rubberasan elastomerimpactmodifier dispersed to plastic matrix which is hence toughened[1 ,2 ] .But as the toughness ofplastic is improved,the elastomerimpactmodifieralso reducesthe othermechanical propertiesof the material.Consequently,whether rigid par…     

Effect of Different Organic Modifiers on the Tensile Properties of PVC／EVA／Montmorillonite Composites

Poly (vinyl chloride)/ethylene-vinyl acetate/montmorillonite (PVC/EVA/OMMT) composites were prepared by melt blending method. Two kinds of montmorillonites were organically modified by trimethyloctadecyl ammonium and dimethyl bis (hydrogenated tallow) ammonium, respectively. The morphology and tensile properties of the resultant composites were discussed in terms of the modifier type and OMMT content. The PVC/EVA/OMMT composites have intercalated structure, which is independent of the polarity of the modifiers, while the tensile properties show strong dependence on the modifier type. The OMMT modified by polar modifier gives higher tensile ductile and strength of PVC/EVA/OMMT composites.     

聚合物共混物脆韧转变性能研究 V.橡胶粒子的分布对聚氯乙烯/丁腈橡胶共混物韧性刚性关系的影响

聚合物共混物脆韧转变性能研究Ｖ．橡胶粒子的分布对聚氯乙烯／丁腈橡胶共混物韧性刚性关系的影响刘浙辉朱晓光张学东漆宗能（中国科学院化学研究所工程塑料国家重点实验室北京１０００８０）蔡忠龙（香港理工大学应用物理系香港九龙）王佛松（中国科学院北京...     

聚氯乙烯－丁腈橡胶－氯丁橡胶三元共混物的研究

测定了聚氯乙烯（ＰＶＣ）－丁腈橡胶（ＮＢＲ－２９）－氯丁橡胶（ＣＲ）三元共混物的冲击性能和应力－应变行为，用动态力学分析、扫描电镜和透射电镜研究了共混物的相容性和形态结构，结果表明，ＮＢＲ－２９对ＰＶＣ，ＣＲ有良好的增容作用，三元共混物是部分相容的二相体系，具有良好的抗冲击性能。     

Poly (vinyl chloride)/poly (α‐methylstyrene–acrylonitrile)/acrylic resin ternary blends with enhanced toughness and heat resistance

In this study, tough and high heat‐resistant poly (vinyl chloride) (PVC)/poly (α‐methylstyrene–acrylonitrile) (α‐MSAN) blends (70/30) containing acrylic resin (ACR) as a toughening modifier was prepared. With the addition of ACR, heat distortion temperature increased slightly, which corresponded with the increase in glass transition temperature measured by differential scanning calorimetry and dynamic mechanical thermal analysis. Thermogravimetric analysis showed that addition of ACR improved the thermal stability. With regard to mechanical properties, tough behavior was observed combined with the decrease in tensile strength and flexural strength. A brittle‐ductile transition (BDT) in impact strength was found when ACR content increased from 8 to 10 phr. The impact strength was increased by 34.8 times with the addition of 15 phr ACR. The morphology correlated well with BDT in impact strength. It was also suggested from the morphology that microvoids and shear yielding were the major toughening mechanisms for the ternary blends. Our present study offers insight on the modification of PVC, since combination of α‐MSAN and ACR improves the toughness and heat resistance of pure PVC simultaneously. Copyright © 2011 John Wiley & Sons, Ltd.     

纳米级SiO_2填充PVC/CPE复合材料研究

80年代以后发展起来的纳米材料被称为“2 1世纪最有前途的材料” ,已成为材料学中跨世纪的研究热点[1 ] 。纳米级无机粒子 /聚合物复合材料是纳米材料中的一种具有重要价值的新型材料 ,可广泛应用于橡胶、塑料、纤维三大合成材料之中[2 ] 。其中 ,纳米级ＳｉＯ2 是纳米材料中的重要一员 ,它被称作跨世纪的高科技材料[3] 。因此 ,本文就纳米级ＳｉＯ2 填充ＰＶＣ/ＣＰＥ复合材料进行探讨。1　实验部分自制 纳米级 (和普通超细 )ＳｉＯ2 ,平均粒径约为 5 0ｎｍ ,比表面积约为 30 0ｍ2 /ｇ ,经过特殊表面处理 ,再用偶联剂、分散剂处理 ,1 2 0…     

Morphology and fracture behavior of toughening‐modified poly(vinyl chloride)/organophilic montmorillonite composites

Toughening‐modified poly(vinyl chloride) (PVC)/organophilic montmorillonite (OMMT) composites with an impact‐modifier resin (Blendex 338) were prepared by melt intercalation, and their microstructures were investigated with wide‐angle X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The mechanical properties of the PVC composites were examined in terms of the content of Blendex and OMMT, and the fracture toughness was analyzed with a modified essential work of fracture model. Intercalated structures were found in the PVC/OMMT composites with or without Blendex. Either Blendex or OMMT could improve the elongation at break and notched impact strength of PVC at proper contents. With the addition of 30 phr or more of Blendex, supertough behavior was observed for PVC/Blendex blends, and their notched impact strength was increased more than 3319% compared with that of pristine PVC. Furthermore, the addition of OMMT greatly improved both the toughness and strength of PVC/Blendex blends, and the toughening effect of OMMT on PVC/Blendex blends was much larger than that on pristine PVC. Blendex and OMMT synergistically improved the mechanical properties of PVC. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 286–295, 2004     

界面粘结对聚氯乙烯/丁腈橡胶共混物脆韧转变的影响

应用丙烯腈（ＡＮ）含量不同的丁腈橡胶（ＮＢＲ）与聚氯乙烯（ＰＶＣ）共混，研究了界面粘结对ＰＶＣ／ＮＢＲ共混物脆韧转变的影响．结果表明：当基体层度Ｔ相等时，过强的界面粘结，使ＰＶＣ／ＮＢＲ共混物的冲击强度降低，并且其产生脆韧转变的临界基体层厚度Ｔｃ减小．界面粘结对于聚合物共混物的增韧行为具有直接的影响．损伤区分析给出：随着界面粘结强度增大，空洞化过程受阻，减弱能量的耗散，并且不利于诱导剪切屈服损伤的产生，因而不利于增韧；但是界面粘强度过小，意味着共混物的相容性太差，致使分散相粒径过大，也不利于增韧．所以对增韧来讲，共混物的界面粘结强度存在一个最佳范围．