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Modification of Natural Rubber by Grafting with Hydrophilic Vinyl Monomers
Author(s) -
Kangwansupamonkon Wiyong,
Gilbert Robert G.,
Kiatkamjornwong Suda
Publication year - 2005
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200500255
Subject(s) - potassium persulfate , polymer chemistry , monomer , grafting , copolymer , methacrylate , emulsion polymerization , chemistry , natural rubber , polymerization , butyl acrylate , acrylate , materials science , polymer , organic chemistry
Summary: The grafting of two hydrophilic vinyl monomers, dimethylaminoethyl acrylate (DMAEA) and dimethylaminoethyl methacrylate (DMAEMA), onto natural rubber latex was carried out by emulsion polymerization using redox initiation. The effects of the redox initiator concentration and type (cumene hydroperoxide/tetraethylenepentamine, CHP/TEPA; tert ‐butyl hydroperoxide/tetraethylenepentamine, t ‐BHP/TEPA; potassium persulfate/potassium metabisulfite, K 2 S 2 O 8 /K 2 S 2 O 5 ), the monomer concentration and the reaction temperature on the conversion, the grafting efficiency, the water absorption and the contact angles of the grafted copolymers films, and the colloidal stability of the latexes at low pH, were investigated. Infrared spectroscopic analysis confirmed that DMAEA and DMAEMA were grafted onto the natural rubber particles. The hairy layer structure of NR‐ g ‐poly(DMAEMA) latex particles was investigated by transmission electron microscopy using positive and negative stainings with OsO 4 and phosphotungstic acid, respectively.TEM micrograph of NR‐ g ‐poly(DMAEMA) latex particles stained with 2% OsO 4 .