PE-LLD-g-（GMA-co-St）的反应挤出及应用

摘要

Glycidyl methacrylate (GMA) and styrene (St) grafting linear low density polyethylene (PE-LLD) [PE-LLD-g-(GMA-co-St)] was prepared by reactive extrusion. The effects of St content and reactive time on grafting rate and melt flow rate (MFR) of PE-LLD-g-(GMA-co-St) were studied. The results show that the best mass ratio of St and GMA is 5︰9 and the best reactive time is 120 s,meanwhile the grafting rate is 1.69%and the MFR is 0.69 g/10 min (190℃,2.16 kg). The prepared PE-LLD-g-(GMA-co-St) and PE-LLD-g-MAH were used for halogen-free flame retarding cable (HFFRC) as compatilizers,and the tensile properties before and after water boiling aging were contrasted. The results show that compared with PE-LLD-g-MAH,the HFFRC using PE-LLD-g-(GMA-co-St) as compatilizer has low tensile strength but high elongation at break and high water boiling aging resistance, the tensile strength and elongation at break is 13.9 MPa and 231%respectively and the retention after water boiling 10 h is 84.9%and 85.7%respectively,which can meet the requirements of the cable industry standard.%采用反应挤出方法，制备了甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St)接枝改性的线型低密度聚乙烯(PE-LLD)产品[PE-LLD-g-(GMA-co-St)]。研究了St用量和反应时间对PE-LLD-g-(GMA-co-St)接枝率和熔体流动速率(MFR)的影响。结果表明，当St与GMA质量比为5︰9，反应时间为120 s时，所制备试样接枝率达到1.69%， MFR (190℃，2.16 kg)达0.69 g／10 min。将制备的PE-LLD-g-(GMA-co-St)和PE-LLD-g-MAH作为相容剂应用于聚乙烯无卤阻燃电缆料，对比了水煮老化前后的拉伸性能。结果表明，与PE-LLD-g-MAH为相容剂的电缆料试样相比，以PE-LLD-g-(GMA-co-St)为相容剂的电缆料试样虽然拉伸强度较低，但具有较高的断裂伸长率和较高的耐水煮老化性能，其拉伸强度和断裂伸长率分别为13.9 MPa和231%，水煮10 h后的保留率分别为84.9%和85.7%，满足电缆行业应用标准要求。