Study On Muti-Monomer Melt Grafting Onto IPB-1and Its Modifying PBT

Multi-monomer grafting onto isotactic polybutene-1(iPB-1) was prepared using Dicumyl Peroxide (DCP) or Butyl Peroxide (DTBP) as the initiator in the XSS-300mixer. The effects of initiator and monomer species, comonomer concentration and species on the grafting degree, grafting efficiency and Melt Flow Rate (MFR) of the resulted grafting iPB-1were investigated respectively. The results showed that the grafting laws were similar for DCP or DTBP as the initiaor in each of grafted systems. Decene-1as the comonomer can slightly increase the the grafting degree and grafting efficiency of GMA, while AMS as the comonomer cant basically improve Gd and Ge of GMA. Both of two comonomers can remarkably enhance the Gd and Ge of MAH.Crystal morphology of the grafted iPB-1were observed by PLM and samples were prepared through adopting two cooling ways of rapid cooling and natural cooling. Compared with these polarized light photos, the samples of natural cooling with heating stage, their sphaerocrystals were more perfect and bigger, On the contrary, the samples of rapid cooling their sphaerocrystals were imperfect and small while the number of the grains were more. With grafting degree of iPB-1improving the size of sphaerocrystals would be smaller and the number of the grains would be more. In addition, with Gd improving the contact angle of grafted iPB-1and water were gradually declining, which showed the surface polarity of grafted iPB-1were gradually enhanced.The preparation of blends of iPB-1and iPB-1grafted by GMA (iPB-g-GMA) modifying butylene terephthalate(PBT) and its crystalline properties as well as mechanical properties were investigated. The results showed the suitable melt blending time of PBT and iPB-1was7min. Neither PBT/PB-1nor PBT/iPB-g-GMA/iPB-1appeared maltese cross phenomena in the polarizing microscope photographs.The crystalline morphology of polymer blends were different from unique crystalline morphology of a single polymer inside it. Grains of two polymers were spread over the noncrystalline regions. In the case of modifying PBT, it has been proved that the mechanical properties of PBT modified by iPB-g-GMA were much better than that of modified by iPB-1. In the PBT/iPB-1blends, separation of two phases were very obvious. But in the PBT/iPB-g-GMA (70/30) blend, the adhesion between the two phases was so strong that the phase separation disappeared and compatibility of two phases was improved. DSC results showed PBT/iPB-g-GMA had better miscibility than PBT/iPB-1.