论文部分内容阅读
利用亲电反应及自由基反应分别对聚苯醚进行了不同程度的溴化。测定了不同温度下对O_2和N_2的透过率及相应的玻璃化转变温度和密度。发现苯环上的溴化有利于提高O_2和N_2的透过率,而选择性基本不变。甲基上的溴化大大提高了O_2、N_2的选择性,但透过率下降较多。苯环上溴含量与Tg呈很好的线性关系,密度亦随溴含量的增加而增加。透过率与温度的关系符合Arrhenius方程。溴化后的聚苯醚其透过活化能略有下降,并计算了溴化聚苯醚的摩尔自由体积和摩尔内聚能,发现其比值越大,O_2、N_2的透过率越大。
The polyphenylene ether was brominated by electrophilic reaction and free radical reaction respectively. The transmissivity of O 2 and N 2 and the corresponding glass transition temperature and density at different temperatures were measured. It was found that bromination on the benzene ring was beneficial to improve the transmittance of O 2 and N 2, while the selectivity was almost unchanged. Bromination on methyl greatly increased the selectivity of O 2 and N 2, but the transmittance decreased more. The bromine content on the benzene ring showed a good linear relationship with Tg, and the density also increased with the increase of bromine content. The relationship between transmittance and temperature accords with Arrhenius equation. The brominated polyphenylene ether showed a slight decrease in the activation energy and calculated the molar free volume and molar cohesive energy of brominated poly (phenylene ether). The larger the ratio, the greater the O 2 and N 2 transmittance.