Research On Ternary-monomer Solid Phase Grafting Modification Polyethylene

Low-density polyethylene?LDPE?become one of the most promising thermoplastic polymer material because of its low price,light weight,excellent physical and chemical properties.However,polyethylene is a non-polar structure,its dyeability and hydrophilicity,adhesion,antistatic properties,and other inorganic filler in compatibility is poor,which limits its application area.Graft modified polyethylene can improve the performance of its hydrophilicity,adhesion,biocompatibility,electrical conductivity,print resistance,antistatic properties,antifouling properties,lubricating properties and polarity,expanding its application areas.Maleic anhydride?MAH?,styrene?St?,butyl acrylate?BA?as the grafting monomer,benzoyl peroxide?BPO?as an initiator,solid-phase graft modified LDPE to improve its polarity and hydrophilicity.Supercritical CO₂?SC-CO₂?and organic solvent A as a swelling agent,benzoyl peroxide?BPO?as initiator,successed grafted MAH,St and BA onto LDPE macromolecular chains,the factors of initiator dosage,monomer dosage,swelling condition and graft reaction conditions were studied.By Fourier transform infrared spectroscopy?FTIR?and thermal gravimetric analysis?TG?were characterization the graft product.SC-CO₂ assistance LDPE solid phase graft modified compared with pure solid phase graft modified,can improve the uniformity and the performance of the graft product.The experimental results show that the ratio of LDPE:BPO:monomer-10:0.04:0.6,swelling temperature of 38 °C,swelling pressure 9MPa,swelling time of 2 h,the reaction conditions of 100 °C/2.5h,interface agent xylene of 1.2 mL,the graft degree highest,5.04%,and the grafting efficiency of 83.91%.Characterized by infrared spectroscopy shows that ternary-monomer successfully grafted onto LDPE macromolecular chains,thermal gravimetric analysis showed that the graft product thermal stability is improved.LDPE of the solubility parameter of 7.94?cal.m-3?1/2,the solubility parameter of the organic solvent A is 8.8?ca1.m-3?1/2,due to the more similar the solubility parameters of the two substances,so the organic solvent A can be a good swelling and assist LDPE graft modified.The results show that the material ratio ratio of LDPE:BPO:monomer 10:0.035:0.6,swelling temperature of 35°C,organic solvent A 16g,swelling time 2.5h,the reaction conditions for 100 °C/2.5h,the interface agent xylene dosage 1 mL for graft degree highest,of 5.13%.Characterized by infrared spectroscopy shows that ternary-monomer successfully grafted onto LDPE macromolecular chains,thermal gravimetric analysis showed that the graft product thermal stability is improved compared with the raw materials.