聚乙烯具有非常突出的耐低温性能
Polyethylene has outstanding low temperature resistance
PE管的低温脆化点为-70℃，优于其他管道。在冬季野外施工时聚氯乙烯（PVC-U）管容易脆裂，我国北京地区铺设聚氯乙烯（PVC-U）埋地给水管试点工程中总结的一条经验是温度在零度以下就不适宜进行聚氯乙烯（PVC-U）管的铺设施工了。还有一个明显的佐证，为改进PP的韧性和低温耐冲击性能，可将乙烯与丙烯单体共聚制成无规共聚聚丙烯（PP-R），其一般采用iPP的工艺路线和方法，使丙烯和乙烯的混合气体进行共聚合，得到主链中无规则地分布着丙烯化粪池模具 精密铸造 钢纤维 盐水注射机 风电基础模具 nsk轴承经销商 nsk轴承总代理 保定空调移机和乙烯段的共聚物（即PP-R管材料），PP-R管材料中的乙烯含量大多在3%左右。但改善后的PP-R耐低温性能仍不尽人意，其脆化点约为-15℃，远高于聚乙烯管的脆化点温度-70℃。
The low temperature embrittlement point of PE pipe is - 70 ℃, which is better than other pipes. In winter field construction, PVC-U pipe is easy to be brittle. One of the experience summarized in the pilot project of laying PVC-U buried water supply pipe in Beijing is that the temperature below zero is not suitable for laying PVC-U pipe. In order to improve the toughness and low-temperature impact resistance of PP, ethylene and propylene monomer can be copolymerized to produce random copolymerized polypropylene (PP-R). Generally, IPP process route and method are used to copolymerize the mixture of propylene and ethylene to obtain the copolymer (i.e. PP-R pipe material) with irregular distribution of propylene and ethylene segments in the main chain Most of the ethylene content in the feed is about 3%. However, the low temperature resistance of PP-R is still unsatisfactory. The brittleness point of PP-R is about - 15 ℃, which is much higher than - 70 ℃ of polyethylene pipe.