Separation and quantification of dead species in styrene RAFT polymerization by gradient polymer elution chromatography was written by Guo, Ruiwei;Shi, Zhipeng;Wang, Xingxing;Dong, Anjie;Zhang, Jianhua. And the article was included in Polymer Chemistry in 2012.Application of 27249-90-7 This article mentions the following:
In living polymerization, the inevitable dead chain impurities, due to bimol. termination and side reactions, are not only an obstacle for the synthesis of pure block copolymers but also an impairment in the application performance of the resulting polymer materials. In this paper, a simple separation and quantification method based on gradient polymer elution chromatog. (GPEC) was developed to exptl. investigate the dead species in RAFT polymerization of styrene. The RAFT-prepared polystyrene (PSt) was extended with Me acrylate in a specially-designed chain extension reaction, in which the living PSt chains were extended and transformed into block copolymer, but the remaining dead PSt chains (D-PSt) will remain constant and can be separated and quantified by GPEC. The systematic exptl. investigation of the effect of various polymerization parameters on the mass fraction of dead species (fD-PSt) in RAFT-prepared polystyrene (PSt) was implemented. The results clearly demonstrated the initiator concentration and RAFT agent concentration can exhibit a linear and inversely proportional dependence on fD-PSt, resp. In addition, the dead chains were found to be formed throughout the entire RAFT process. These unambiguous exptl. data confirmed the previous theor. calculation and model prediction, which may be beneficial to understand RAFT processes, optimize polymerization conditions and to minimize dead polymer contaminations. Moreover, the method based on GPEC proposed here was able to fractionate and quantify the dead and living species, which can serve as a powerful tool in the mechanistic study of the living radical polymerizations In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Application of 27249-90-7).
Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Application of 27249-90-7
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics