PET/SiO_2纳米复合材料的光学性能和结晶成核行为

Research on the Optical Properties and Crystallization Behavior of PET/SiO_2 Nanocomposites

以乳液聚合法制备了聚甲基丙烯酸甲酯(PMMA)包覆纳米S iO2的核-壳结构复合粒子,并利用聚合法和共混法制备PET纳米复合材料。研究了复合颗粒和纳米复合材料的制备条件和方法等对复合材料光学和结晶成核行为的影响。结果表明:分散良好的纳米颗粒对PET有很强的成核作用,抑制PET球晶生长速度,提高PET总结晶速率和透明度。共混法制备的纳米复合NPET透明度提高,而聚合法制得的NPET透明度降低。NPET熔融结晶行为表明,随着纳米颗粒含量增加,NPET双熔融小峰逐步降低;纳米S iO2含量2%时,NPET的结晶速度最快,结晶半峰宽仅有5.1℃。

The core-shell SiO2/PMMA nanocomposite particles were prepared by emulsion polymerization in which polymethyl methacrylate encapsulated nano-silica. A new composite material （NPET） was prepared through SiO2/PMMA nanocomposite particles melted with poly （ethylene terephthalate） （PET）, and its optical properties and crystallization behavior were investigated. Results show that uniformly dispersed inorganic particles in PET produce strong nucleation effect on it. Nanoscale inorganic particles reduce the growth rate of spherulites, but increase the rate of crystallization and enhances the transparence of nanocomposites. The nanoparticle encapsulation experiments show that, as the deionized water and iso-butanol increase, nanoparticles disperse more easily in solution, so the transparence is higher. As the nanoparticles load increase, NPET transparence increases at first, then decrease. At the optimized load of 2 nanoparticles, NPETts transparence reaches the highest value of 89%, while, its crystallization rate is the quickest, and its half-width temperature of crystallization peak （Tb1/2） is 5. 1 ℃.