tailieunhanh - Synthesis of hydroxyl terminated liquid natural rubber by oxidative depolymerization of deproteinized natural rubber

The chemical structure of HTLNR was determined by FTIR and 1H-NMR and 13C-NMR spectroscopic analysis. Based on the analytical data the mechanism of depolymerization and hydroxylation of NR to form HTNR was also suggested. | Tạp chí Khoa học và Công nghệ 54 (3) (2016) 340-346 DOI: SYNTHESIS OF HYDROXYL TERMINATED LIQUID NATURAL RUBBER BY OXIDATIVE DEPOLYMERIZATION OF DEPROTEINIZED NATURAL RUBBER Le Duc Giang*, Dinh Mong Thao, Hoang Thi Huong, Le Thi Thu Hiep Faculty of Chemistry, Vinh University, 182 Le Duan, Vinh City * Email: Leducgiang@ Received: 6 October 2015; Accepted for publication: 21 December 2015 ABSTRACT Hydroxyl terminated liquid natural rubber (HTLNR) was prepared by the depolymerization of deproteinized natural rubber (DPNR) in mixture of toluene and water at 60 oC for 24 hours in the presence of ammonium persulfate as an initiator and tetrahydrofuran (THF) as a homogenizing agent. GPC analysis revealed that the number-average molecular weight (Mn) and weight-average molecular weight (Mw) of HTLNR were found to be ×103 g/mol and ×103 g/mol, respectively, with polydispersity index (PDI) of . The chemical structure of HTLNR was determined by FTIR and 1H-NMR and 13C-NMR spectroscopic analysis. Based on the analytical data the mechanism of depolymerization and hydroxylation of NR to form HTNR was also suggested. Keywords: deproteinized natural rubber (DPNR), hydroxyl terminated liquid natural rubber (HTLNR), depolymerization of natural rubber, oxidative degradation. 1. INTRODUCTION Liquid natural rubber (LNR) is a modified form of natural rubber (NR) with shorter polymeric chains. LNR has some benefits for making adhesives, coatings and sealants. It is also used for various rubber goods other than tires, for example, anti-vibration rubber, fender, conveyer belt for mining, rubber hose and so on. Especially, the LNR with terminated functional groups are very useful for use as intermediates, for example, reactive compatibilizers plastisizers, modifiers as well as in chain extension and grafting reactions [1 - 3]. There are some main methods that are used to make LNR such as depolymerization of NR by thermal, mechanical, .