Polymer Chain Extension Research

The lower molecular weight polymer obtained by the general polymerization method is about 20,000 or less, and the relative viscosity is low, while the relative viscosity of the resin used in engineering plastics is relatively high. Therefore, the research and development of high molecular weight polymers has become the main goal of scientific research. Polymers will inevitably produce a certain amount of waste in the production of plastic profiled materials. Generally speaking, recycled raw materials are obtained through the recovery, crushing and re-granulation of waste polymers. In the process of recycling and granulation, the tensile strength and viscosity of the recycled materials are greatly reduced due to the aging, pollution, and water absorption of the polymer. Therefore, in order to obtain high-performance materials, people have been researching and developing. One is to increase the relative molecular weight through polycondensation, and the other is to increase the viscosity through blending modification methods such as grafting, crosslinking, and chain extension.

The chain extender is added to the polymer melt. During the blending process, the active functional group of the chain extender reacts with the chain end functional group of the polymer, thereby connecting two or more polymer molecular chains to improve The purpose of the relative molecular mass of the polymer. The introduction of chain extenders as a new method of thickening is simple and easy to implement, and is suitable for large-scale industrial production.