In this work

long chain branched (LCB) polypropylene (PP) was prepared by multimonomer melt grafting with the presence of 1

6hexanediol diacrylate (HDDA) and styrene (St) in a Haake Rheomix batch mixer.FTIR spectra showed the addition of St to the melt grafting system could significantly promote the graft degree of HDDA onto PP backbones.For fixed initiator and HDDA monomer content

the more the addition of St monomer

the higher the graft degree of HDDA monomer was.Investigations on the rheological properties of grafted PP indicated the existence of LCB structures.During melt grafting

the graft degree of HDDA monomer increased

melt flow rate (MFR) of the grafted PP decreased and more LCB PP was generated with increasing the St monomer concentration.Derivative thermogravimetry (DTG) measurements showed that the thermal stabilities of the grafted PP were greatly enhanced

which was much better than iPP.The decomposition temperatures

known as T5% and Tmax

were more than 46 K higher than iPP

and more than 30 K higher than grafted PP without St

implying the thermal stabilities of the grafted PP were greatly enhanced by multimonomer melt grafting with St and HDDA monomers.Xray diffraction (XRD) results demonstrated the graft processing by multi-monomer melt grafting could well induce the crystallization of PP form crystals.Differential scanning calorimetry (DSC) characterization showed that grafted PP had higher crystallization temperature and wider melting and crystallization peaks

due to the heterogeneous nucleation effect and restriction of the existence of grafted PP chains

respectively.