Study On The Preparation And Performance Of Grafting Of PE

The compatibility and adhesion between polyethylene and other material can be improved via grafting-modified polyethylene to introduce polar or functional group. The application realm of polyethylene can be extended in this way.The author chose linear low density polyethylene/high density polyethylene (LLDPE/ HDPE) as matrix resin, maleic anhydride (MAH), glycidyl methacrylate (GMA), itaconic acid (ITA) as three typical grafted monomer,adding equal amount of styrene(St) as second monomer, and dicumyl peroxide(DCP) as initiator to research the melt grafting reaction by Hakke rheometer.The effects of the ratio of LLDPE/HDPE, monomer and initiator concentrations were investigated and the graft products which had better graft degree, MFR and adhesion were gained. The graft structure and graft degree were determined and tested by IR spectra and DSC. The graft rate of graft product was quantitative analysis in the way of chemical titration. The effects were research, which were different monomers and initiator concentrations on the fluidity, adhesion, mechanical properties, heat resistance.The results were showed:The IR spectra and chemical titration showed MAH, GMA, ITA were successfully grafted onto the PE main chain.The DSC result showed:due to the graft-modification, the tacticity of molecular chain and the activity of PE decreased, and the crystallized capacity increased and then decreased with the increasing of the amount of grafted monomers.After the grafted with ITA, the adhesive property of LLDPE/LDPE/HDPE were improved, and the order of peel strength:LLDPE>HDPE>LDPE; when the mass ratio of LLDPE/HDPE was 4/6 to 6/4, the graft product had a higher peel strength and the vicat softening point temperature can reach over 100℃.In the system of PE grafted MAH, the result showed that the graft product of PE had better adhesion and fluidity, when DCP was as initiator and in amount of 0.05% to 0.06% by comparison of the initiator of DCP and double 2,5/BPO, so DCP was chose as initiator, the content of monomer of MAH/St was 0.60%.In the system of PE grafted GMA, when the content of monomer of GMA/St was 1.50% to 2.00%, of initiator of DCP was 0.15% to 0.20%, the graft product of PE had better comprehensive performance. In the system of PE grafted ITA, when the content of monomer of ITA/St was 0.10% to 1.50%, of initiator of DCP was 0.15% to 0.20%, the graft product of PE had better comprehensive performance.In comparison of the grafted MAH, the grafte product of grafted GMA and ITA, the adhesion and fluidity increases, and the odor pungent decreases. So, the monomer of GMA and ITA can instead of MAH as graft monomer and graft PE.