Graft copolymers of natural rubber and poly(dimethyl(acryloyloxymethyl)phosphonate) (NR-g

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• 作者：Daniel Derouet ; Punyanich Intharapat ; Quang Ngoc Tran ; Fré ; dé ; ric Gohier ; Charoen Nakason
• 关键词：Graft copolymer ; Natural rubber ; Photopolymerization ; Dimethyl (acryloyloxymethyl)phosphonate ; Dimethyl(methacryloyloxyethyl)phosphonate ; Latex
• 刊名：European Polymer Journal
• 出版年：2009
• 出版时间：March 2009
• 年：2009
• 卷：45
• 期：3
• 页码：820-836
• 全文大小：1237 K

文摘

Graft copolymers of natural rubber and poly(dimethyl(acryloyloxymethyl)phosphonate) (NR-g-PDMAMP), and natural rubber and poly(dimethyl(methacryloyloxyethyl)phosphonate) (NR-g-PDMMEP), were prepared in latex medium via a “grafting from” methodology based on the photopolymerization of dimethyl(acryloyloxymethyl)phosphonate (DMAMP) and dimethyl(methacryloyloxyethyl) phosphonate (DMMEP), respectively, used as phosphorus-containing monomers. The grafting polymerization was initiated from N,N-diethyldithiocarbamate groups previously bound in side position of the rubber chains. The effects of monomer concentration on monomer conversion and grafting rate were investigated, showing that conversion and grafting rate increased with increasing monomer concentration and reaction time. Highest conversions and grafting rates were obtained with a molar ratio [DMAMP]/[initiating units] = 7 for a reaction time of 180 min. Calculation of the graft average length () from ¹H NMR spectra of the synthesized graft copolymers showed values were in the range of 9–73. Visualizations of NR-g-PDMAMP and NR-g-PDMMEP latices by Transmission Electron Microscopy (TEM) showed that they exhibit core-shell morphologies. Degradation of NR-g-PDMAMP and NR-g-PDMMEP occurred in two steps: decomposition of dimethylphosphonate-functionalized grafts took place prior to the second step corresponding to the decomposition of NR backbone, but the degradation temperature of this last step was higher than that of pure NR.