组成结构   PVC电缆保护管

Composition structure

聚氯乙烯是一种使用一个氯原子取代聚乙烯中的一个氢原子的高分子材料，是含有少量结晶结构的无定形聚合物。这种材料的结构如下：[ ―CH2 ―CHCl― ]n。PVC是VCM单体多数以头-尾结构相联的线形聚合物。碳原子为锯齿形排列，所有原子均以σ键相连。所有碳原子均为sp3杂化。

Polyvinyl chloride (PVC) is an amorphous polymer which uses a chlorine atom to replace a hydrogen atom in polyethylene. The structure of this material is as follows: [- CH2 - CHCl - n]. PVC is a linear polymer with head-tail structure, most of which are VCM monomers. Carbon atoms are aligned in a zigzag pattern, and all atoms are connected by_bonds. All carbon atoms are SP3 hybrids.

在PVC分子链上存在短的间规立构规整结构。随着聚合反应温度的降低，间规立构规整度提高。聚氯乙烯大分子结构中存在着头头结构、支链、双键、烯丙基氯、叔氯等不稳定性结构、使得耐热变形及耐老化差等缺点。故作交联后，可将该类缺点消除。

There is a short syndiotactic structure in the molecular chain of PVC. The regularity of syndiotactic structure increases with the decrease of polymerization temperature. In the macromolecule structure of polyvinyl chloride, there are some unstable structures, such as head structure, branched chain, double bond, allyl chloride, tertiary chloride, which make the thermal deformation resistance and aging resistance poor. This kind of shortcomings can be eliminated after crosslinking.