论文部分内容阅读
利用扫描电镜和红外线光谱技术研究了聚酯(PET)纤维在高温下于纯水中的水解降解过程。发现未拉伸的PET纤维在纯水中于200℃经过30分钟之后,其表面已经开始产生显著的应力裂化降解现象,随着反应温度的升高或反应时间的延长,这种现象越加严重,导致纤维断裂成为长度大致为10—20μm的短纤维段及粉末状的低聚物。在250℃经过30分钟(或者在280℃经过瞬间)之后即全部水解转化为原来的单体对苯二甲酸和乙二醇。产物中还有一系列的缩醇及其对苯二甲酸的单酯这一事实表明,在水解同时还存在缩合和再酯化的可逆反应过程。
The hydrolysis and degradation process of polyester (PET) fiber in pure water at high temperature was studied by scanning electron microscopy and infrared spectroscopy. The unstretched PET fibers were found to have undergone significant stress-cracking degradation upon exposure to pure water at 200 ° C for 30 minutes. This phenomenon is exacerbated as the reaction temperature is increased or the reaction time is extended , Resulting in breaking of the fibers into staple fiber lengths and powdered oligomers of approximately 10-20 [mu] m in length. All of the hydrolysis was converted to the original monomeric terephthalic acid and ethylene glycol at 250 ° C for 30 minutes (or at 280 ° C for an instant). The fact that there is also a series of acetals and their monoesters of terephthalic acid in the product shows that there is also a reversible reaction of condensation and re-esterification along with hydrolysis.