Grafting of Phosphonate Monomer onto Natural Rubber Latexes via Emulsion Polymerization

摘要

The synthesis of phosphorus-containing monomer, methacryloyloxyethyl phenyl benzenephosphonate (MPBP), was carried out. The monomer was successfully prepared as evidenced by ~1H NMR, ~(13)C NMR, FT-IR and MS analyses. Subsequently, MPBP was grafted onto natural rubber particles via emulsion polymerization. It was found that as the reaction temperature increased from 40 to 70°C, percent grafting efficiency increased from 72% to 85%. Transmission electron microscopy (TEM) of the grafted NR showed a semi core-shell morphology. Thermogravimetric analysis (TGA) of grafted NR indicated a two step degradation. Moreover, the grafted polyMPBP promoted the char residue of up to 3.5%. Flame tests revealed that the grafted NR exhibited an increased LOI value (20.5%) over that of pure NR (17.0%).