Analysis on Property and Structure of PPR Cold and Hot Water Pipe Special Resin
The relative molecular weight and distribution,molecular sequence structure,thermal crystallization classification,melting temperature and crystallization temperature of three types of random copolymer polypropylene(PPR)special resins for cold and hot water pipes with different short term static hydraulic performance(referred to as PPR-1,PPR-2,PPR-3)were analyzed.The correlation between short term static hydraulic performance and the structural composition of polypropylene resin was studied.The results show that the melt flow rate,molecular weight and distribution and content of ethylene of the three PPR special resins for cold and hot water pipes are basically consistent,but there are differences in the dispersion of ethylene and the regularity of polypropylene chains.The ethylene dispersion and polypropylene chain regularity of PPR-1 comonomer are both low.The comonomer ethylene is more distributed on molecular chains with relatively small molecular weights,resulting in lower local strength of the material.The possibility of local damage to the pipe under high pressure is higher,and short term static hydraulic performance is lower.
random copolymer polypropylenepipehydrostatic pressure
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