The Research Of Water Bringing Agent On The Crosslinking Of Vinyl Silane Grafted Polyethylene

In this paper, polyethylene was melting grafted with vinyl silane in thereactor of HAAKE Rheometer, and then water bringing agent was added toit, a period of time later, crosslinked stuff was obtained. The paperresearched the effect of the water bringing agent to hydrolyze, crosslinkingand rheological property of grafted stuff, meanwhile, discussed thecapillary rheological property and crystal performance of grafted andcrosslinked stuff.The results indicate that when DCP content is 0.005phr and the dosageof grafting monomer vinyl silane is invariable, the torque is added slowlyalong with the time protract. When DCP content is more than 0.015phr, alltorque curves have a rise trend at first, then decline, the torque is increasedalong with the increasing of DCP content, and the time reached torque peakin curves is in advance. After adding some water bringing agents, thetorque of grafted stuff is rising quicken, especially when NaH₂PO₃·2H₂Oor melamine is added, the torque is doubled all. From gel content testingdata, the crosslinking velocity of grafted stuff with adding water bringingagent can be improved obviously. Rheological performance of grafted stuff research indicate that alongwith the increasing of the HAAKE rotate speed, the peak value of thetorque curves increase, and the time reaching torque peak in curves is inadvance, meanwhile the stuff temperature rise more rapid. Capillaryrheological testing show that the system is pseudo-plastic fluid, as shearrate increasing, the dependence of shear viscosity on temperature is lower.MFR tests indicate that the MFR of grafted stuff is minished along with theincreasing of DCP content: Infrared Spectra Analysis evidenced that thegrafting and crosslinking reaction is occurred.DTA results indicate that the melt and crystal apex of grafted stuff isminished gradually along with the increasing of DCP dosage. DSC testingresults indicate that the crystal temperature, crystal degree and crystalspeed of grafted stuff are declined along with the increase of DCP content;after adding different water bringing agent, the crystal degree ofcrosslinked stuff is lower than relevant grafted stuff; when the waterbringing agent is HCOONa·2H₂O, the crystal temperature is the minimum.From the deflection light microscope, we can see obvious crystal grain inthe grafted stuff, but we can not see obvious crystal grain in the crosslinkedstuff.