مرکز منطقه ای اطلاع رساني علوم و فناوري -

چكيده لاتين :

Aseries of oil gels based on the rigid hydrophobic monomer 4-tert-butylstyrene (tBS) and the soft oleophilic monomer ethylene-propylene-diene (EPDM) crosslinked with divinylbenzene (DVB) were synthesized by suspension polymerization. Effects of EPDM and DVB contents on swelling behaviours, compressive properties, effective cross-link density (Ve), average molecular weight between cross-links (Me)י and polymer-solvent interaction parameter (X1) of oil gels were studied. It has been shown that the equilibrium oil absorbency (Oeq) is first increasing and then decreasing with the increase of EPDM contents in polymerization, as well as Me values. On contrary, the values of Ve first rise and then decline with the increase of EPDM contents, as well as the volume fraction of polymer in gel (!/J ,) and X1 values. The optimum reaction conditions are EPDM content 60 wt% and DVB content 3 wt%. Further increase of DVB content leads to changes of swelling behaviour, network structure and polymer-solvents interaction in oil gels, viz. the decrease of Oeq and Me values, the increase of qJ" Ve, and X1 values. These changes represent macroscopically the varieties of compressive strength and Youngיs modulus of the oil gels. The comparison between efficient cross-linking density and theoretical cross-linking density (V t) indicates that the double bonds in EPDM monomeric unit has participated in chemical cross-linking, and the physical cross-linking and entanglements have thr weakening effects on chemical cross-linking.