【作者】 叶朝阳；

【导师】 顾宜；

【作者基本信息】 四川大学 ， 材料学， 2002， 硕士

【摘要】 本文分析了蛭石精矿和膨胀蛭石的组成和结构，用十六烷基三甲基溴化铵（CTAB）进行了有机化处理，再通过熔融或溶液混合插层苯并嗯嗪树脂（BEN）制备了BEN插层蛭石纳米复合材料，并采用蒙脱土进行了对照实验。XRD分析表明：蛭石精矿是由蛭石、水金云母及金云母所组成。有机化处理使蛭石晶层的d₀₀₁由1.46nm增加到2.67nm，并出现二级衍射峰d₀₀₂=1.34nm。经BEN插层后，蛭石层间距进一步增大，插层效果优于蒙脱土，而水金云母层间距没有变化；复合物固化后，有机化蛭石和水金云母的特征峰都消失了。DFM分析表明：在蛭石含量低于3％时，形成主要以剥离状纳米分散为主的固化结构，相邻蛭石晶片间距可达到113nm，随着蛭石含量的增多，逐渐形成以插层状纳米分散为主的固化结构，相邻蛭石晶片间距在40nm左右。直接插层膨胀蛭石也能形成BEN插层蛭石纳米复合材料。 通过对双酚A型BEN／蛭石纳米插层物固化过程的分析：不同蛭石含量的插层物，在形成不同纳米分散状态固化结构的过程中，蛭石晶片对双酚A型BEN的热开环聚合有明显不同的阻碍作用，蛭石含量为3％的插层物160℃的凝胶化时间较纯树脂的延长约7min，活化能高约8KJ／mol，固化反应热晗低约14J／g，使得固化物的固化程度较纯树脂低约10％，阻碍作用最大，其它含量的次之。TGA分析：固化物在第二微分失重峰（300℃～550℃）处迅速失重64％，没有第三失重峰，而在此处树脂失重仅8.5％。这些分析表明：双酚A型BEN／蛭石的固化结构为固化不完全的交联密度更低的聚合网络结构。 双酚A型BEN／蛭石纳米复合材料的力学性能和热性能表现出明显的结构特征，普遍地低于纯树脂的性能数值，而优于双酚A型BEN／金云母复合约 ZI％和 ZS“ 热变形温度＊DT)低约 3℃，线膨胀系数高约 3．4几插层状分散的10％蛙石含量的纳米复合材料的物理交联作用表现较为明显，力学性能处于峰值；HDT高于纯树脂，并随含量的增加而提高，含金云母的复合材料的HDT则不随其含量变化而变化。 多元酚型BEN／蛙石插层纳米复合物固化后，其热稳定性明显提高。膨胀蛙石含量为20％时，插层纳米固化物的起始热分解温度高于金云母的约35t。以多元酚型BEN／蛙石插层纳米复合物为主要成分制备的火车合成闸瓦的摩擦性能和力学性能得到明显改善，具有摩擦系数带宽较窄m．35～0．45人摩擦系数高，无明显的“过恢复”和“热衰退”等现象，机械性能优良等特点。更多还原

【Abstract】 Polybenzoxazine/vermiculite hybrid nanocomposites were prepared from two kinds of polybenzoxazine precursors and two kinds of organically modified-vermiculite minerals and expanded-vermiculite which were consisted of vermiculite ,hydrobiotite and phlogopite. After treatment of vermiculite minerals by hexadecyl trimethylam monium bromide(CTAB), the d001 of vermiculite layers of vermiculite mineral increased from 1.43nm to 2.67nm and developed a d002=1.34nm. After organically modified vermiculite intercalated with a polybenzoxazine precursor ( bisphenol A type), The d001 of vermiculite layers increased from 2.67nm to 3.63nm further and developed a d002=1.82nm and a d003=0.91nm. It showed that the polybenzoxazine precursor had intercalated into vermiculite layers. Cured the composites, the diffraction peak of vermiculite d001 in XRD spectrum disappeared . According to Atomic force microscopy (AFM) images, in the cured-composites, when the content of vermiculite minerals was less of 3%, most crystals were cleaved into the "exfoliated" shape in which crystalgallery breadth was about of 113nm. As the content of vermiculite minerals increased, the content of the "intercalated" shape, in which crystal gallery breadth was about of 40nm, also increased.In the curing reaction processing of polybenzoxazine/vermiculite hybrid nanocomposites intercalated with bisphenol A type precursor. According to the content of vermiculite minerals, while different shape of crystal was forming, these crystals were retarding the heat ring-opening polymerization of bisphenol A type precursors in the nanocomposites. As the content of vermiculite minerals was about 3%. the retardance was the most. Compared with bisphenol A type precursor itself, the tgel and the activation energy(Ea) of the curing reaction increased 7min and 8KJ/mol respectively, the enthalpy(Hd) of the curing reaction decreased 14 J/g. As a result, the cure-degree of the polybenzoxazine/vermiculite hybrid nanocomposites decreased 10%. The cured products had lower cure-degree and even lower cross-linking density. The weight loss at the second peak (300C~550C) of DTGA was 64%, but the weight loss of polybenzoxazine(bisphenol A type) itself was only 8.5%.Mechanics properties and heat resistant properties of the polybenzoxazine(bisphenol A type)/ vermiculite hybrid nanocomposites were lower than those of the polybenzoxazine(bisphenol A type) but prior to those of the polybenzoxazine(bisphenol A type)/phlogopite composites. As the content of vermiculite minerals was about 3%, the impact strength (nick) , the flexural strength and the heat distortion temperature (HDT) of the nanocomposites all were the lowest and decreased 21% , 28% ,3C, respectively. Compared with those of the polybenzoxazine(bisphenol A type) , its thermal expanded coefficient (TEC) was 3.4% bigger than that of the polybenzoxazine(bisphenol A type) . when the content of vermiculite minerals was about 10%, the impact strength (nick) and theflexural strength had maximum value ,but those of the polybenzoxazine(bisphenol A type)/phlogopite composites had been going down. As the content of vermiculite minerals was over 5%. HDT of the polybenzoxazine(bisphenol A type)/ vermiculite hybrid nanocomposites was higher than that of the polybenzoxazine(bisphenol A type). HDT of the polybenzoxazine(bisphenol A type)/phlogopite composites not changed in the range of phlogopite content from 0%to 15%.Heat resistant property of the polybenzoxazine(mulitphenol type)/ vermiculite hybrid nanocomposites was prior to that of the polybenzoxazine(mulitphenol type)/phlogopite composites. As the content of the expanded vermiculite was 20%, the Tonset of the polybenzoxazine(mulitphenol type)/ vermiculite hybrid nanocomposites from its TGA cure was 35 Chigher than that of the polybenzoxazine(mulitphenol type)/phlogopite composites. High-performance train brake plate was developed with the polybenzoxazine(mulitphenol type)/ vermiculite hybrid nanocomposites. It has a narrow brand strip of friction coefficient (0.更多还原