Modification of Polypropylene-graft-Maleic Anhydride with Epoxy by Reactive Extrusion for Preparation of High-Melt-Strength Polypropylene

A high-melt-strength polypropylene (HMSPP) was prepared using a twin-screw extruder from a commercial maleic anhydride-grafted polypropylene (PPgMA). The grafted polymer was reacted with epoxy resin (ER) to generate long chain branches (LCBs) in the molecular structure of the PPgMA. Different concentrations of ER up to 2.36 wt. % was employed to obtain different levels of branching. Fourier transformed infrared (FTIR) spectroscopy indicated that maleic anhydride groups reacted with epoxy. The melt flow rate (MFR) test showed that the melt strength of the HMSPP improved considerably. Furthermore, the LCB efficiency of the HMSPP was analyzed by Rheometeric Mechanical Spectrometer (RMS).