Preparation And Properties Of PBS Modified By SiO₂ Grafted With Hyperbranched Polymer

Among the biodegradable materials,polybutylene succinate?PBS?has become a research hotspot due to its relatively low price,high melting point,and g^od overall performance.Filling modification is a common method for modification of polymer materials.However,the improvement of mechanical properties is often accompanied by a significant increase in the viscosity of materials during the modification process,which is not conducive to the processing of materials and brings adverse effects.In order not to increase or even reduce the processing viscosity of the material,in this paper,PBS was modified by filling ultrafine silica which was grafted with hyperbranched polymer,and the effects of the grafting amount of hyperbranched polymer and the filling amount of ultrafine silica grafted with hyperbranched polymer on the melt viscosity and other properties of PBS composites were studied.The polymer was grafted onto the ultrafine silica surface through the method of"grafting from".First,the surface of silica was modified with silane coupling agent KH-550 to obtain SiO₂-KH550;then,silica grafted with different generations of hyperbranched polyester?SiO₂-HBPE?and hyperbranched polyamide?Si O₂-HBPA?were prepared by the reaction of SiO₂-KH550 with different monomers.The results showed that different generations of hyperbranched polymers were successfully grafted on the surface of SiO₂.Composites were prepared by melt blending SiO₂-HBPE and SiO₂-HBPA with PBS respectively,and the properties of the composites were characterized.The results showed that the addition of SiO₂-HBPE and SiO₂-HBPA to PBS had made the comprehensive mechanical properties of the composites better than those of pure PBS and SiO₂/PBS composites,however,the melt viscosity of the composites decreased,which did not affect the processing of PBS composites.The complex viscosity of the system increased with the increase of SiO₂ content when the filler is SiO₂.When the fillers were SiO₂-HBPE1³,the complex viscosity decreased with the increase of generation and addition amount.And when SiO₂-HBPE3 was added and the addition amount was 2.0%,the viscosity of the system was reduced by nearly 48%compared to pure PBS and 66%compared to SiO₂/PBS composites when the content of SiO₂was 2.0%.When the system fillers were SiO₂-HBPA1³,the viscosity of the composites were also lower than pure PBS and SiO₂/PBS composites but the viscosity of the composite material increased with the increase of the added amount of the same generation filler.When the addition of SiO₂-HBPA2 was 0.5%,the viscosity of the system was the lowest.In addition,the addition of SiO₂-HBPE and SiO₂-HBPA in PBS reduced the spherulite size of PBS,but had little effect on its crystallization and melting behavior,dynamic mechanical properties,and thermal stability.