Optimization Of The Synthesis Process Of P-Methylene Quinones And Study Of The Properties Of Derivatives

Styrene is an important chemical raw material used in the manufacture of synthetic rubber,plastics,resins and other products,as well as in pharmaceuticals,household appliances and toy manufacturing.Styrene is prone to self-polymerization during transportation,production and storage causing unnecessary losses.In order to reduce the loss of styrene monomer self-polymerization during storage,transportation and production at room temperature,it is necessary to add a polymerization inhibitor.At present,most of the traditional polymerization inhibitors are nitro-phenolic polymerization inhibitors,which are polluting and contradict the current advocated environmental protection concept.The p-methylene quinone(p-QMs)class polymerization inhibitors belong to the third generation of polymerization inhibitors,with low toxicity,green and other characteristics,the application potential.p-QMs are an important class of quinone derivatives,which are structural motifs commonly found in various organisms as well as natural products.The p-QMs have a special dienone structure,a compound containing two unique α,β-unsaturated carbonyl groups with strong electrophilic properties.Since p-QMs is readily aromatizable,it readily undergoes 1,6-nucleophilic addition reactions.p-QMs are currently synthesized mainly by the Mannich reaction method,but most Mannich reactions for the synthesis of p-QMs use readily toxic reagents such as piperidine and hydrochloric acid,and p-QMs have been developed over a relatively short period of time.Therefore,there are still many problems to achieve industrialization,and it is necessary to explore a low-cost,green and highly efficient industrialization route.The main work of this thesis is to test the polymerization resistance of p-QMs analogues,to optimize the synthesis process and to synthesize 1,6-addition products of p-QMs.This thesis consists of the following two parts:1.Five p-QMs analogs were synthesized based on the Mannich reaction method using different aldehydes and 2,6-di-tert-butylphenol as raw materials and tested for their barrier properties.The process conditions for the synthesis of QMS-1polymerization inhibitor,which has a better inhibiting effect,were explored and optimized in terms of solvent,raw material ratio,catalyst,catalyst dosing method,reaction duration and post-treatment method,respectively,and scaled-up experiments were conducted under the optimized conditions to verify the feasibility of industrialization.2.1,6-addition reaction studies of p-QMs and fluoroboron pyrrole-like fluorescent dyes(BODIPY).The p-QMs underwent 1,6-nucleophilic addition reactions with BODIPY catalyzed by Lewis acid,and the target 1,6-addition products obtained all possessed fluorescence properties.And the photophysical properties of the synthesized six 1,6-addition products of p-QMs were tested in different polar organic solvents.