โ Scribed by Wiyong Kangwansupamonkon; Robert G. Gilbert; Suda Kiatkamjornwong
No coin nor oath required. For personal study only.
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; tertโbutyl hydroperoxide/tetraethylenepentamine, tโBHP/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 NRโgโpoly(DMAEMA) latex particles was investigated by transmission electron microscopy using positive and negative stainings with OsO~4~ and phosphotungstic acid, respectively.
TEM micrograph of NRโgโpoly(DMAEMA) latex particles stained with 2% OsO~4~.
magnified imageTEM micrograph of NRโgโpoly(DMAEMA) latex particles stained with 2% OsO~4~.
๐ SIMILAR VOLUMES
In this study, ceric salt-and g-ray-initiated graftings were used in comparison with photografting because both are a typical initiation system for chemically initi-In a previous article, 1 photografting was applied to ated and radiation-initiated graftings on cellulosic mafunctionalize cellulose an