Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

Polymers

Suhawati Ibrahim¹  Rusli Daik²  Ibrahim Abdullah² 

[1] Chemistry and Materials Exploratory Unit, Technology and Engineering Division, Malaysian Rubber Board, 47000 Sungai Buloh, Selangor, Malaysia; E-Mail:;School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia; E-Mail:

关键词: NR degradation;    liquid natural rubber;    functionalized natural rubber (NR);    OH terminated rubber;   

DOI  :  10.3390/polym6122928

来源: mdpi

【 摘 要 】

Natural rubber (NR) is a high molecular weight natural polymer and can be degraded to liquid natural rubber (LNR) leaving certain functional groups at the end of chains. In this study, LNR samples prepared via oxidative degradation using H₂O₂ and NaNO₂ as reagents were found to have different end groups depending on the pH of the reaction medium. In an acidic medium, LNR with hydroxyl terminal groups was formed as the degradation reaction was initiated by hydroxyl radicals produced from decomposition of peroxynitrite acid. In contrast, a redox reaction took place in an alkaline medium to yield LNR with carbonyl terminal groups. The mechanisms of reaction are discussed and proposed to explain the formation of different end groups when reaction carried out in acidic and alkaline media. Chain degradation in an acidic medium seems to be more effective than in an alkaline medium, and thus yields LNR with lower M_n.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.