PPR管材专用树脂的结构与加工性能

Structure and processability of random copolypropylene special resin for pipes

通过核磁共振分析和相对分子质量分布测试研究了无规共聚聚丙烯（PPR）管材专用树脂的结构与性能,确定了试样的最佳挤出实验条件,完成了优化条件下挤出管材的静液压试验和爆破试验。PPR管材专用树脂的乙烯摩尔分数为3%~4%,重均分子量为55×104左右,挤出加工温度为230℃时制品性能最佳;管材制品规格为准32 mm×2.9 mm时,爆破压力超过4.200 MPa,并通过了3.8 MPa,95℃,165 h的静液压测试。

The structure and properties of 3 grades of random copolypropylene （PPR） special resins for pipes were studied by nuclear magnetic resonance analysis and relative molecular mass distribution test. The optimal extrusion conditions of the resins were determined; hydrostatic test and bursting test of the pipes produced under the above conditions were completed. The properties of the PPR pipes reached the optimum when the resins＇ molar fraction of ethylene was 3%-4%, weight average molecular mass was about 55×10^4 and the extrusion temperature was 230 ℃. The bursting pressure of the pipe was over 4200 MPa when its dimension specification was 432 mm×2.9 mm; the pipes also passed the hydrostatic test under the conditions of 3.8 MPa, 95℃ and 165 h.