Study On GMA Multi-Monomer Functionalized Modified Isotactic Polybutene-1

Glycidyl methacrylate(GMA)-vinyltoluene(VT)or divinyl benzene(DVB)multi-monomer melt-grafting onto isotactic polybutene-1(iPB-1)were prepared in a torque rheometer.The effects of dicumyl peroxide(DCP),GMA,VT or DVB concentrations on GMA grafting degree(Gd),grafting efficiency(Ge)and product melt flow rate(MFR)were investigated.The results showed that the grafting degree of GMA was increased significantly,because of the addition of comonomer(VT or DVB),and the MFR of grafted products reduced,especially the DVB comonomer grafting system,the MFR declined more obvious than VT comonomer grafting system;The increase of initiator DCP concentration can promote the GMA grafting degree,but it can cause the degradation of macromolecular chain,lead to the increase of MFR;the amount of GMA in the graft system increases,the MFR of the product decreases.The reaction mechanism of DCP initiated comonomer/GMA melt-grafting of iPB-1 was studied by means of FTIR and melt flow rate.The results showed that,in VT comonomer grafting system,VT first reacted with iPB macromolecular radicals to form relatively stable macromolecular free radicals,and then grafted with GMA,it had a certain promoting effect on the improvement of GMA grafting degree;In DVB comonomer grafting system,DVB reacted with GMA which had been grafted on the iPB-1 macromolecular chain,to stabilize and greatly increase grafting degree.Both comonomers(VT and DVB)can effectively inhibit the degradation of iPB-1 macromolecules.The thermal stability,crystal morphology and crystallization rate of iPB-1 and its grafted products(iPB-g-GMA)were studied by means of thermogravimetric analysis(TGA),polarized light microscopy(POM)and differential scanning calorimetry(DSC),the non-isothermal crystallization kinetics of iPB-1 and its its grafted products were described by the Avrami method,the Ozawa method and the Mo Zhishen method.The results showed that the presence of GMA grafted chain can reduce the thermal stability of iPB-1,refine the grain of iPB-1,reduce the size of spherulites,and promote the process of nucleation,which significantly shortened the spherulite growth time of iPB-1;at the same cooling rate,the crystallization rate of iPB-g-GMA was faster than that of iPB-1;the Avrami index of grafted producted deviated,the Ozawa method and Mo Zhishen method can be used to analyze the non-isothermal crystallization of iPB-1 and its grafted products;GMA grafted chain can significantly reduce the iPB-1 of crystallization activation energy and increase the crystallization ability of iPB-1.