A new series of polybenzoxazine-silica (PBZ-SiO2) hybrid nanocomposites were developed using hydroxyl terminal benzoxazine monomers (BZ-OH) and TEOS through the in-situ sol—gel method. The formation of hybrid nanocomposites was confirmed by FT-IR. The presence of inter-cross linked silica networks in PBZ-SiO2 hybrids was accounted for their excellent thermal stability and better char yield than those of neat PBZs. The confinement of the mobility of the polymer chain arose from the introduction of silica particles into the polybenzoxazine matrix increased the glass transition temperature of the hybrids. The values of dielectric constant of the nanocomposites were decreased with increased silica content. The reduction in percentage water uptake may be associated with the inherent hydrophobic nature of Si—O—Si network present in the PBZ-SiO2 hybrid systems. The shift in both the absorption and emission wavelength revealed the successful incorporation of silica particles through thermal ring opening polymerization of benzoxazine and TEOS. The molecular level dispersion of SiO2 particles in the polybenzoxazine matrices was evidenced from morphological studies.
通过原位溶胶-凝胶法,使用羟基端苯并恶嗪单体(
BZ-OH)和 TEOS 开发了一系列新的聚苯并恶嗪-
二氧化硅(P
BZ-SiO2)杂化纳米复合材料。傅立叶变换红外光谱(FT-IR)证实了杂化纳米复合材料的形成。与纯 P
BZ 相比,P
BZ-SiO2 杂化物具有优异的热稳定性和更高的
炭化率,其原因在于 P
BZ-SiO2 杂化物中存在相互交叉连接的
二氧化硅网络。在聚苯并恶嗪基体中引入
二氧化硅颗粒后,聚合物链的流动性受到限制,从而提高了杂化物的
玻璃化转变温度。纳米复合材料的介电常数值随着
二氧化硅含量的增加而降低。吸
水百分比的降低可能与 P
BZ-SiO2 杂化体系中存在的 Si-O-Si 网络固有的疏
水性有关。吸收波长和发射波长的变化表明,通过苯并恶嗪和 TEOS 的热开环聚合,
二氧化硅颗粒成功地加入到了体系中。形态学研究证明了
二氧化硅颗粒在聚苯并恶嗪基质中的分子级分散。