What is XLPE insulation and chemical properties?

The insulation material cross-linking polyethylene is a new polymer insulation material developed on the basis of polyethylene, and the general heat shrink tube and the heat shrink sleeve are made of cross-linked polyethylene insulation material. Its molecules use crosslinking, that is, by chemical or physical methods, to change the molecular structure of polyethylene from a straight chain to a mesh structure in three-degree space.

The physical crosslinking method is to irradiate polyethylene with high-energy particle rays, so that polyethylene is combined with each other into a three-degree spatial mesh structure of cross-linking polyethylene. At present, we commonly use cross-linked polyethylene overhead insulation wire, that is, produced in this way.

The chemical method is to mix the chemical cross-linking agent into the polyethylene material, in which the independent polyethylene molecule becomes cross-linking polyethylene through a new molecular combination. The cross-linking process is shown in Figure .

Polyethylene has been cross-linked, greatly improving the mechanical, heat- and creep-resistant and environmental cracking properties of polyethylene, as shown in Table 2113. It can be seen from the table that the above performance of cross-linked polyethylene is superior to polyethylene, and it basically maintains the electrical properties of polyethylene. The presence of crosslinking makes cross-linked polyethylene not soluble as PE, and can be decomposed and carbonized only after a long period of action when the temperature exceeds 300 degrees C.

XLPE绝缘材料的化学性能

什么是XLPE绝缘材料的化学性能？

绝缘材料交联聚乙烯是在聚乙烯基础上发展起来的新型高分子绝缘材料，一般热缩管和热缩套管都是由交联聚乙烯绝缘材料制成。它的分子通过采用交联法，即利用化学或物理方法，将聚乙烯的分子结构从直链状变为三度空间的网状结构。

物理交联方式是用高能粒子射线照射聚乙烯，使聚乙烯相互结合成三度空间网状结构的交联聚乙烯。目前我们常用的交联聚乙烯架空绝缘线，即是用这种方法生产的。

化学方法是在聚乙烯料中混入化学交联剂，在化学反应中，使独立的聚乙烯分子通过新的分子组合而成为交联聚乙烯。其交联过程如图2一13所示。

聚乙烯经过交联后，大大提高了聚乙烯的机械、耐热、抗蠕变以及抗环境开裂性能，如表2一13所示。从表中可看出，交联聚乙烯的上述性能要比聚乙烯优越，同时它还基本保持了聚乙烯的电气性能。交联的存在使交联聚乙烯不像PE那样能够溶化，只有当温度超过300℃时，经过长时间作用后才能够分解和炭化。