低熔点聚酰胺的结晶和熔融行为

采用差示扫描量热法和X射线衍射法对低熔点聚酰胺的结晶和熔融行为进行研究,考察了共聚单体、等温结晶温度和时间对样品结晶和熔融行为的影响。结果表明:经等温结晶后的样品再次升温时,均出现了双熔融峰,且随等温结晶温度的升高或时间的延长,低温熔融峰向高温方向移动,而高温熔融峰则基本不变。等温结晶温度80℃时,两种样品的熔融焓值均较大,并且随结晶时间的延长会变大。X射线衍射结果表明:随着结晶温度的升高或时间的延长,衍射峰变得尖锐,样品的结晶度增大。添加了十二烷基二胺的切片B比添加癸二胺的切片A具有更好的结晶能力,比较适合纺丝加工。

Crystallization and Melting Behaviors of Low Melting Point Polyamide

Effects of comonomer, isothermal crystallization temperature and time on the crystallization and melting behaviors of low melting point polyamide were investigated via differential scanning calorimeter and X-ray diffraction(XRD). Experimental results indicated that two melting peaks were appeared in the isothermal crystallization processes. The lower melting peak was moved towards higher temperature with either increasing isothermal crystallization temperature or time, while the higher melting peek was kept relatively constant. A high melting enthalpy value of samples was showed up at 80 ℃ and raised with the increase of isothermal crystallization time. XRD results showed that the diffraction peaks were sharper, and crystallinity was gradually raised with the extension of crystallization temperature or time. Addition of dodecyl diamine made sample B had a better crystallization ability than that of decamethylene diamine in the sample A, and sample B was more suitable for spinning processes.