POM 23P杜邦

POM 23P杜邦---POM can be divided into homoformaldehyde and copolyformaldehyde according to the different chemical structures in the molecular chain. Homoformaldehyde is generally obtained by polymerization of anhydrous paraformaldehyde, and copolyformaldehyde is the copolymeric product of POM and a small amount of dioxolane. It is due to the different structure that leads to the difference of homopolymer and copolyformaldehyde in various properties. The main differences between the two are: homoformaldehyde has higher density and crystallinity, melting point and HDT are 10 ℃ higher than that of copolyformaldehyde, and the strength, creep resistance and friction resistance are better, but the thermal stability is poor, the processing temperature range is about 10 ℃, and the acid-base stability is low.

POM按分子链中化学结构的不同可分为均聚甲醛和共聚甲醛两种，均聚甲醛一般是由无水聚甲醛聚合而得，共聚甲醛是由三聚甲醛与少量二氧戊环的共聚产物。正是由于结构上的不同，导致均聚和共聚甲醛在各项性能下存在差异。两者主要区别是：均聚甲醛密度、结晶度较高，熔点与HDT较共聚甲醛高10℃，强度、耐蠕变性能和耐摩擦性能更优越，但热稳定性差，加工温度范围窄约10℃，对酸硷的稳定性较低。

23p physical property table
Test method of physical performance rating unit
Specific gravity 1.42 ASTM d-792 / ISO r1183
Mechanical properties - rating units - Test methods
Izod notch impact strength: 80 kg / cm ASTM d-256 / ISO R180
Flexure coefficient 30000 kg / cm ASTM D-790 / ISO 178
Elongation at break 35% ASTM d-638 / ISO r527
Tensile strength 640 kg / cm ASTM d-638 / ISO r527
Thermal performance rating unit test method
Hot deformation temperature ASTM d-648 / ISO 75
133 ℃
(0.46MPa) 168 ℃
Melting point: 175 ℃