环氧改性剂对PA6/EVOH共混物性能的影响

Effect of Epoxy Modifiers on Properties of PA6/EVOH Blends

介绍了不同环氧改性剂对聚酰胺6(PA6)/乙烯⁃乙烯醇共聚物(EVOH)共混物的拉伸性能、流变性能、结晶性能的影响,并研究了甲基丙烯酸缩水甘油酯(GMA)与共混物的反应机理。使用转矩测试、红外光谱、氢核磁共振、拉伸测试、旋转流变测试和差示扫描量热法对共混物进行了表征。结果表明,随着改性剂环氧值的增加,共混物的共混转矩、拉伸强度、复数黏度和储能模量均增加,共混物的结晶度和结晶温度降低,断裂伸长率呈先升高后降低的趋势;考虑到加工过程的流动性,GMA改性的共混物性能最佳,拉伸强度提高了8.5%,断裂伸长率提高了26.6%;红外光谱和氢核磁共振表明,GMA可以在高温下发生自聚合反应,形成多环氧低聚物,进而与PA6和EVOH反应,提高共混物的性能。

This work reported an investigation on the effect of different type of epoxy modifiers on the tensile properties,rheological properties,and crystallization properties of PA6/EVOH blends.The reaction mechanism of glycidyl methac⁃rylate(GMA)with blends was also and explored.The blends were characterized with torque test,Fourier⁃transform in⁃frared spectroscopy(FTIR),hydrogen nuclear magnetic resonance(NMR),tensile tests,rotational rheological test and differential scanning calorimetry.The results indicated that the blends showed an increase in blending torque,tensile strength,complex viscosity and storage modulus with an increase in the epoxy value of modifiers increases.Their crystal⁃linity and crystallization temperature was found to present a decrease with the epoxy value,whereas the elongation at break tended to increase at first and then decreased.With polyepoxy groups in the molecules,most of epoxy modifiers can react with amine,carboxyl or hydroxyl groups for chain extension to improve the properties of the blends.Taking into account the fluidity issue in the processing procedure,the GMA⁃modified blend has the optimal properties with the ten⁃sile strength increased by 8.5%and elongation at break increased by 26.6%.FTIR and 1H⁃NMR characterization re⁃sults indicated that GMA underwent self⁃polymerization at high temperatures to form polyepoxy oligomers.These oligo⁃mers can react with PA6 and EVOH to improve the properties of their blends.