Papers by Keyword: Melt Grafting

Abstract: Maleic anhydride grafted C₅ petroleum resin (C₅-g-MAH) was prepared using peroxide as an initiator by melt grafting process, and was incorporated as a compatibilizer into Wood Flour/High Density Polyethylene (WF/HDPE) composites. The effect of second monomers and C₅-g-MAHs on the morphology and mechanical properties of composites was investigated. Results showed that the presence of a second monomer, Triallyl isocyanurate (TAI), Butyl acrylate (BA) or Trimethylol proane trimethacrylate (TMPTMA), in the grafting system gave rise to higher grafting ratio of C₅-g-MAHs compared to that without a second monomer. The highest grafting ratio was obtained as TMPTMA content being 0.20~0.35wt% based on C₅. The addition of C₅-g-MAHs into WF/HDPE resulted in improved mechanical properties. Meanwhile the composite containing C₅-g-MAH with 0.30wt% TMPTMA exhibits the most significant improvement in all mechanical properties with tensile strength and bend strength increasing up to 18% and 20% respectively, which is concomitant with the finer morphology structure observed by SEM, suggesting the remarkable compatibilizing effect of C₅-g-MAH with TMPTMA for WF/HDPE composites.

Abstract: The melt grafting of maleic anhydride (MAH) onto poly (3-hydroxybutyrate-co-4-hydrox-ybutyrate)[P(3HB-co-4HB)]/polylactic acid (PLA) blends were carried out via reactive extrusion. The effects of the contents of MAH, initiator (BPO) on the graft ratio were studied. The effects of grafting modification on thermal properties, mechanical properties, fracture morphology and compatibility of P(3HB-co-4HB)/PLA blends were characterized by differential scanning calorimeter (DSC), electronic universal testing machine and scanning electron microscopy (SEM) etc. The results showed that the graft ratio of blends increased to a maximum and then decreased with increasing contents of MAH and BPO; The tensile strength, impact strength of blends were significantly improved, and the graft ratio achieved the maximum value at 1.0phr MAH and 0.3phr BPO; Through analysis from DSC and SEM, it indicated that the compatibility of P(3HB-co-4HB)/PLA blends was improved effectively.

Abstract: A novel approach to functionalize polypropylene (PP) is presented. This method consists of two steps. Firstly, oligomers of glycidyl methacrylate (GMA) were synthesized via UV photo-polymerization using benzophenone (BP) as initiator. Secondly, the GMA oligomers were grafted onto PP, which was initiated by the free radicals generated through the reactivation of semipinacol dormant groups in the oligomers. By this method, the functionalization of PP could be facilely achieved in a simple system without either organic peroxide initiator or monomer; additionally, degradation of the substrate PP was not observed. This presentation is mainly focused on the characterization of the grafted PP products by XRD, DSC and TGA measurements. It is demonstrated that the melting temperature, crystallinity and the initial decomposition temperature of the grafted PP were all increased, compared with those of the origin PP; the functionalization of PP led to the change of the crystal form from the mixed form of α and β into only α form.