International Polymer Processing, Vol.19, No.4, 356-363, 2004
Side chain extension of maleated polypropylene with diamine
In this study melt reaction of maleated polypropylene (PP-g-MA) with hexamethylene diamine (HMDA) and poly(propylene glycol)-bis-(2-propylamine) (Jeffamine D-400) was carried out. Three kinds of PP-g-MA (Polybond 3002, Polybond 3150 and Polybond 3200) having different maleic anhydride content of 0.2, 0.5, 1.0 wt.% respectively were used. FTIR spectra show that branches and crosslinks were formed through the formation of amide and imide linkages between maleic anhydride group and diamine, and titration results show that the reactivity of HMDA to maleic anhydride group is higher than that of Jeffamine D-400. For Polybond 3002, increases in melt index and decreases in molecular weight was found after reaction as a result of chain degradation. Hence increases in viscosity and moduli were not found in reacted Polybond 3002. Polybond 3150 and Polybond 3200 with higher MA content shows increase in molecular weight after reaction, and gels were detected when high concentration of HMDA was reacted. Increases in shear viscosities and modulus were observed in Polybond 3150 and Polybond 3200. In elongational viscosity measurement, when higher concentration of HMDA used, strain hardening was observed in Polybond 3150 and Polybond 3200.