复配增塑剂对聚乙烯醇薄膜的增塑效果

Effect of mixed plasticizers to PVA films

为改善PVA结晶度高、不易加工的问题,采用溶液共混的方法制备了复配增塑剂改性的聚乙烯醇(PVA)薄膜,通过红外光谱(FT-IR)研究了N,N-二甲基甲酰胺/尿素与PVA的相互作用,利用广角X射线衍射仪(XRD)、示差扫描量热仪(DSC)、热重分析仪(TGA)和力学性能测试考察了增塑改性后PVA薄膜的性能.研究结果表明:N,N—二甲基甲酰胺/尿素能破坏PVA分子中氢键作用,降低PVA的结晶度和熔点,加入复配增塑剂后提高了PVA薄膜的分解温度,拉伸强度降低,断裂伸长率提高,对PVA的增塑作用显著.

Modified polyvinyl alcohol （PVA） films were prepared by casting method using different mixed plasticizers in order to improve the performance of high crystallinity and overcome the difficulty in fabrication. The interactions between N,N-dimethyl formamide/urea and PVA molecules were investigated using FT-IR spectra. The properties of N,N-dimethyl formamide/urea plasticized PVA films were measured using X-ray diffraction （XRD）, differential scanning calorimeter （DSC）, thermo gravimetric analyzer （TGA） and mechanical property test. The results show that the hydrogen bonding in PVA films was formed by N,N-dimethyl formamide/urea. The degree of crystallinity and the melting point of plasticized PVA films were reduced. The thermal decomposition temperature of plasticized PVA films was higher than pure PVA. The PVA film can be soften by the N,N-dimethyl formamide/urea mixture, which results in lower tensile strength and higher elongation at break.