摘要
将改性后的纳米SiO2加入单体EG中超声波分散,然后与TPA搅拌混合置入反应釜中,制备PET/纳米SiO2复合材料。研究了纳米SiO2的用量及其分散形式。用傅立叶红外、SEM分析和观察纳米SiO2在复合材料中的结构和形态,用示差扫描量热法(DSC)分析PET复合材料的结晶行为。结果表明,PET/SiO2复合材料中的纳米氧化硅已经融入到PET基体中。将纳米SiO2在EG中直接用超声波分散,再与TPA聚合得到的复合材料中纳米SiO2粒子存在严重团聚现象;而纳米SiO2和分散剂PEG同时加入EG后用超声波分散,再进行聚合可以明显提高其分散性。DSC分析表明,PET/SiO2复合材料体系的结晶放热峰的宽度增大。当SiO2的量不超过2%时,能够略微提高PET的结晶温度,使结晶过冷度和结晶速率减小;当SiO2含量为3%时,结晶速率常数增大。与非等温结晶动力学分析得到的结果相同。
Composites of PET/nano-SiO2 are prepared by putting the modified nanometer SiO2 into the monomer EG and dispersing by ultrasonic wave. Then they mixed with TPA, and lay it in the autoclave. The content and the dispersed form of nanometer SiO2 in PET/nano-SiO2 are investigated. The structure and morphology of nanometer SiO2 are examined by IR and SEM respectively. The crystallization behavior of the composites is determined by DSC. The results show that nanometer SiO2 particles of PET/nano-SiO2 composites are blended in the matrix of the PET entirely. Directly dispersing nanometer SiO2 in EG and then being polymerized with TPA lead to an aggregation form of SiO2 in the composites, whereas the dispersion is improved obviously when nanometer SiO2 and PEG are added in EG simultaneously, and then be polymerized. The result of DSC shows that the width of thermo-positive peak of the composites is enlarged. When the content of SiO2 is less than 2%, the under-cooling and crystalline rate will decreas, and the crystal temperature will increase slightly. When the content of SiO2 reaches to 3%, the constant of crystalline rate will increase. The investigation of the none-isothermal crystallization dynamic obtaines the same tendency.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2006年第F05期200-202,205,共4页
Materials Reports
