Active free radical polymerization adjusting and controlling agent and preparation thereof

Abstract

The invention discloses an active free radical polymerization adjusting and controlling agent and application thereof. The adjusting and controlling agent is a vulcanization accelerator, namely dithiodiisopropyl xanthate, can be applied to the reversible addition-cracking chain transfer free radical polymerization. A homopolymerization process comprises the following steps: before polymerization, mixing an initiator, the adjusting and controlling agent, a monomer and a solvent; placing the mixture into a reaction bottle; and starting a polymerization reaction at a certain temperature after three times of airtight freeze thawing deaeration. A chain extension process comprises the following steps: before polymerization, mixing the initiator, a macromolecular chain transfer agent, the monomer and the solvent; placing the mixture in the reaction bottle; and starting the polymerization reaction at a certain temperature after three times of airtight freeze thawing deaeration. The active free radical polymerization adjusting and controlling agent has good adjusting and controlling capabilities for a vinyl acetate monomer. In the homopolymerization process, the molecular weight is controllable, grows gradually, and is distributed narrowly; and the chain extension can be carried out based on a homopolymer to obtain a block copolymer. Simultaneously, the adjusting and controlling agent has no irritating flavor, a mature industrial preparation method and low cost.

Description

technical field [0001] The invention relates to the field of macromolecules, in particular to an active radical polymerization regulator and application thereof. Background technique [0002] As an important branch of living radical polymerization, reversible addition-fragmentation chain transfer (Reversible Addition-Fragmentation chain Transfer, RAFT) radical polymerization method has achieved rapid development in the past two decades. This polymerization method has the characteristics of mild conditions and wide application range of monomers, and is widely used in the synthesis of polymers with specific structures such as block, graft, hyperbranched and star. [0003] It is worth noting that the regulator, or chain transfer agent (CTA), plays a very important role in RAFT polymerization, and its activation group and leaving group have a direct impact on the reaction kinetics. Therefore, almost all discussions on the mechanism of RAFT and the design of polymer synthesis wi...

AI Technical Summary

Problems solved by technology

However, the shortcomings of such regulators are also obvious

[0005] First of all, its preparation conditions are relatively harsh, the steps are cumbersome, and its yield cannot be effectively guaranteed

[0006] Secondly, in the preparation process of this type of CTA, due to the acidification of dithio-Grignard reagents and other issues involved, it is easy to emit sulfur-containing gas with a foul smell, which has a greater impact on the environment and health hazards

And this kind of CTA product itself also can emit extremely bad smell, has caused certain hindrance to its industrial application

[0007] In addition, the range of monomers that can be regulated by this type of CTA is limited, and the regulation of some common monomers (such as vinyl acetate) is not common

Images