Controlled/living Radical Polymerization Of St And MMA Mediated By DPETTX

Controlled/living free radical polymerization(CLRP)is a very important and effective method of polymerization.It has developed very rapidly since the end of the last century,but due to the deficiencies and limitations of existing methods,it has limited its industrial-scale production and application.Therefore,this article intends to develop a new CLRP method with a higher degree of controllability/activity,which is simpler,more practical and environmentally friendly.At the same time,it explores the feasibility of industrial applications and the value of industrial applications,increasing the boarder of the CLRP field in some way.For this reason,this article took the lead in using thioxanthone as a substrate,and synthesized a kind of aromatic cyclic thioether small molecule compound(9-(1-phenylethyl)-9,10-dihydroanthracerace-9-yl)sulfane,hereinafter referred to as DPETTX,verified by 'H NMR and 13C NMR,then applied in two aspects.The first aspect:separately initiated and mediated the thermal polymerization of St in toluene,meanwhile,initiated and mediated the photopolymerization of MMA in acetonitrile.The corresponding research was carried out to investigate the initiation and mediation effects of DPETTX,considering the data of polymerization experiments.The data results speculated the mechanism of thermal initiation of monomer polymerization by DEPTTX alone;the second aspect:the use of 2,2'-Azobisisoheptonitrile(abbreviated as ABVN)and DPETTX at the same time respectively for the heat polymerization of St and MMA in toluene.In the polymerization,the effect of DPETTX on the thermal polymerization of St and MMA in toluene was observed and evaluated systematically based on the results of the polymerization experiments.At the same time,the initiation and mediation mechanisms shared by ABVN and DPETTX were guessed based on experimental results.The capture agent captured free radicals and other methods for verification.In St thermal polymerization,we studied different temperatures(55/60/65/70/80/90/100 ?)?DPETTX concentrations(0.43%,1.18%),and ABVN/DPETTX molar ratios(0.05:1/0.1::1/0.2:1)effects on polymerization.The results clearly displayed that when DPETTX was used with itself,it could nomally initiate the polymerization of St in toluene at 80/90/100 ?,but its decomposition efficiency was not high.Under the same conditions,the monomer conversion rate could climb up as the temperature went high,and the highest is 100 ?,the conversion rate reached 50%at 48 h.At the same time,DPETTX had a poor effect on the molecular weight of polystyrene.Even at 100 ?,the Mn went down as the convertion went up,and the PDI gradually ranged from 1.5 to 2.8;and the monomer conversion become smaller when more DPETTX was added,so was the Mn.When ABVN and DPETTX were used in three proportions,the monomer conversion increased with the reaction time at the temperature of 55/60/65/70 ?,the Mn increased too under the previous condition..In the common system,DPETTX had a certain regulation effect on St polymerization.In addition,the smaller the proportion of ABVN,the lower the monomer conversion rate and the higher the polymer molecular weight in the system.In addition,DPETTX can also exhibit some mediation effects of photopolymerization and thermal polymerization of MMA under certain conditions.DPETTX can also act as an initiator to initiate its polymerization in acetonitrile and show better controllability under certain conditions.When ABVN and DPETTX are used at the same time(ABVN/DPETTX=0.2:1,0.1:1,0.05:1),the mass concentration of MMA monomer is 30%at 60 ?,the conversion rate increases with time,and the molecular weight increases with the conversion rate.When ABVN/DPETTX is 0.05:1,it has the most positive effect on the polymerization system.