Study On Crystallization And Properties Of Functionalized Isobutylene-1 Modified Nylon 6

The functionalized modified polybutene-1 was prepared in a twin-screw extruder with diisopropyl peroxide(DCP)as initiator,styrene(St)as co-monomer,glycidyl methacrylate(GMA)and maleic anhydride(MAH)as grafting monomers,and polybutene-1(iPB-1)as raw material,and the properties of the graft were investigated.The results showed that GMA and MAH could be effectively grafted onto iPB-1.The water contact angle of the functionalized iPB-1 was reduced,hydrophilicity was increased,and polarity was enhanced.iPB-g-GMA obtained a large increase in elongation at break and notched impact strength,and the GMA modification could effectively enhance the toughness of iPB-1.The crystallite size of the functionalized iPB-1 was reduced,the number of spherical crystals increased and the radius of spherical crystals decreased.Nylon 6(PA6)was modified with iPB-1 and iPB-g-GMA in blends,and the mechanical and crystalline properties were investigated.The test results showed that:iPB-g-GMA co-blended modified PA6 had improved tensile strength,elongation at break and notched impact strength compared with pure iPB-1 co-blended modified PA6,and iPB-g-GMA co-blended modified PA6 could effectively improve the overall toughness of the blends.The toughness enhancement of the blends by the two iPB-g-GMA graft with different MFRs was different at different blending ratios.At low blending ratios,the iPB-g-GMA with higher MFR showed higher overall toughness improvement,while at high blending ratios,the iPB-g-GMA with lower MFR showed higher overall toughness improvement.The melting temperature(T_m)of the PA6 part of the blends did not change significantly,while the crystallization temperature(T_c)all increased and the crystallization rate was accelerated.The polarized light microscope test shows that:PA6 and iPB-1 blends have obvious crystalline boundary,the boundary between the two phases is clear,and the compatibility is poor;PA6 and iPB-g-GMA blends do not see obvious crystalline boundary,the grains are fine and dispersed,and the compatibility is good.The blends of nylon 6(PA6)were modified with iPB-g-MAH,and the blends were prepared and their mechanical and crystalline properties were investigated.The results showed that the tensile strength of PA6/iPB-g-MAH blends decreased compared with that of pure PA6;the elongation at break increased and then decreased with the increase of iPB-g-MAH content.The melting temperature(T_m)and crystallization temperature(T_c)of the PA6 portion of the blends did not change significantly with the increase of the blending ratio.Compared with pure PA6,the PA6 fraction in the blends required shorter time to reach the same crystallinity,higher crystallization temperature and narrower crystallization temperature range.Polarized light microscopy showed that the two phases of PA6 and iPB-g-MAH in the blends were less compatible and there was a clear phase separation.