Melt-Grafting Of Glycidyl Methacrylate Onto Isotactic Polybutene-1 And Its Applications

Glycidyl Methacrylate (GMA)/Styrene (St) multi-monomer grafting of isotactic polybutene-1 was prepared using different initiators in the Haake mixer and the grafting laws were studied for each initiator. The effects of reaction temperature, monomer and comonomer concentration, initiator concentration and reaction time on the grafting degree, grafting efficiency and Melt Flow Rate (MFR) of the resulted grafting copolymer were investigated respectively. The results showed that the grafting laws were similar for these three different initiators, the highest grafting degree attained was 1.8%; as a comonomer, styrene can remarkably enhance the grafting degree and grafting efficiency.Compared with iPB, the mechanical properties of iPB-g-GMA remained almost unchanged. The surface polarity of iPB-g-GMA which was characterized by the contact angle of iPB-g-GMA with water increased with increasing grafting degree. The existence of (GMA-co-St) side chain can greatly accelerate the crystal formⅡto formⅠtransformation rate of iPB and the transformation rate increases with increasing grafting degree. Study on non-isothermal crystallization showed that, compared with iPB, the melt temperature and crystallinity degree of iPB-g-GMA decreased, initial crystallization temperature and crystallization peak temperature of iPB-g-GMA shifts to higher temperature while crystallization time and crystallization inducting time become shorter. The crystallizing procedure of iPB and iPB-g-GMA described by Ozawa equation showed that under the same temperature, crystallization rate of iPB-g-GMA was faster than that of iPB while the crystallization rate required to reach the same crystallinity in one unit time was smaller than that of iPB. The crystallinity activity energy of iPB-g-GMA was lower than iPB, with -145.02kJ/mol and -94.76kJ/mol respectively.The effects of iPB-g-GMA as the carrier of CaCO₃ and modifying PA6 were investigated. The results showed that, the mechanical properties of CaCO₃ covered by iPB-g-GMA were much better than that covered by iPB; Compared with iPB, the dispersity of CaCO₃ among iPB-g-GMA was more uniform and the mutual combination between them was much stronger. The properties of PP/iPB-g-GMA/ CaCO₃ system were better than PP/iPB/CaCO₃ system. In the case of modifying PA6, it has been proved that the mechanical properties of PA6 modified by iPB-g-GMA were much better than that of modified by iPB; In the PA6/iPB-g-GMA blend, the adhesion between the two phases was so strong that the native crystallization peak temperature of iPB-g-GMA disappeared. At the meantime, the interface of two phases blurred and dispersity of iPB-g-GMA in the PA6 matrix was improved.