Analysis of CPVC heat Resistance code

In the pipeline system for transporting high-temperature steam at 120℃, ordinary PVC has long softened and deformed, while CPVC can remain calm and composed. This magical thermal stability stems from the triple protective code at the molecular level.

The first layer of code is hidden in the chlorine atom matrix. Through chlorination modification, the chlorine content of CPVC has increased from 56% of PVC to 67%-69%. These negatively charged chlorine atoms act like miniature heat sinks, effectively absorbing heat energy and forming an electronic shielding layer. X-ray diffraction shows that the melting point of the crystallization zone of CPVC reaches 210℃, which is 80℃ higher than that of PVC. More importantly, the bond energy of the C-Cl bond formed by chlorine atoms and carbon chains is as high as 327kJ/mol, which is more resistant to vibration than the C-H bond (413kJ/mol).

The second password lies in the cross-linked network architecture. The three-dimensional cross-linked structure formed during the chlorination process hinders the movement of molecular chains. Differential scanning calorimetry (DSC) detection shows that the glass transition temperature (Tg) of CPVC can reach 115-125℃, which is more than 40℃ higher than that of PVC. Test data from a certain chemical enterprise shows that after continuous operation for 8,000 hours at 110℃ and 1.6MPa, the deformation of CPVC pipelines is still less than 2%.

The third code comes from the formula synergy effect. By adding heat stabilizers such as antimony oxide and organotin, the dehydrochlorination reaction of CPVC at high temperatures is effectively inhibited. The practical application in a certain thermal power plant in Qingdao has proved that the modified CPVC steam pipe has a service life of over 10 years under the working condition of 130℃, and the retention rate of thermal aging strength still remains above 85%. This molecular design wisdom makes CPVC the preferred material in high-temperature corrosive conditions.

Shandong AXA Chem Co.,Ltd

June 3, 2025