Study On Mechanism Of Functional Modified Polybutylene Succinate Composites

In recent years,with the improvement of people's awareness of environmental protection,traditional plastics have gradually caused social worries due to their poor degradability.Such as polypropylene(PP),polyethylene(PE),and polystyrene(PS).Biodegradable plastics are considered to solve long-term environmental pollution problems caused by traditional re-degradable plastic.Their development and application have become the forefront and focus of global materials research.Polybutylene succinate(PBS)is a kind of biodegradable material that has been studied in recent years.Wood-plastic composites have the advantages of both wood and plastic,which can be biodegradable,recyclable and reused,relatively high strength and hardness,and friendly to the environment.In this paper,halogen-free flame-retarded PBS composites,interfacial modification-enhanced PBS composites and nano-reinforced PBS composites were prepared by hot-press molding.And through a variety of test methods,the effects of different fiber contents on the mechanical properties,crystallization properties,morphology,crystal structure and heat stability of PBS matrix were compared.Research indicates:1?A series of flame-retardant composites were prepared by using new flame-retardant aluminum hypophosphite(AHP),calcium hypophosphite(CaHP)and ammonium polyphosphate(APP),which were applied to the flame retardancy of PBS.The flame-retardant and thermal properties of the flame-retardant composites were studied by various test methods.And the crystallization and mechanical properties of the materials were also studied.The experimental results show that CaHP can enhance the tensile strength of composites,and the toughness decreases.A small amount of AHP,APP and CaHP can enhance the mechanical properties of composites.When AHP,APP and CaHP were used together,the flame retardant effect of composite materials was the best,the total heat release was the lowest,the amount of smoke released was the least,and the amount of carbon residual was the most.The addition of AHP,APP and CaHP can significantly improve the crystallization performance of the composites and the crystallinity.TG tests have shown that AHP can effectively form a source of acid that catalyzed carbonization under air conditions.CaHP shows better thermal stability than AHP under air conditions,and its air condition is more favorable for CaHP catalyzed carbonization and flame retardant performance.The addition of APP can effectively increase the carbon residual content of composites at high temperatures,and improve the stability of the system under the high temperatures at the same time.2?Study on the modification of PBS with polyethylene glycol,chitosan and TBC in order to improve the mechanical strength and the flexibility.At the same time,based on the significant effect of the nano-AC in the wood plastic composite material,the nano-AC was added to the PBS composite,and then the physical and chemical properties of the PBS composites were studied by a variety of testing methods.The experimental results showed that the mechanical properties of the samples changed significantly after mixing with different proportions of the mushroom wood powder,PBS,PEG,TBC,nano activated carbon(nano-AC)and chitosan.The PEG can reduce the brittleness of PBS and improve the toughness.When the PEG content is 10%of the total mass,the physical and mechanical properties of the wood plastic composite material reach the best state,and the composite material has better comprehensive mechanical properties when the nano-AC is added.The addition of chitosan and TBC has little effect on the physical properties of the composites.However,when chitosan and nano-AC are used together,the properties of the composites have a great influence on the properties of the composites.FT-IR and XRD analysis showed that hydrogen bonds,C-O,C=O,and O-C-O can be formed between PEG and the mushroom wood powder.TGA and DTG analysis showed that the van der Waals forces increased during the crystallization process of PEG,which improved the thermal stability of the composite.The results of TD-GC-MS analysis showed that the organic volatiles in the interface-modified PBS composites were mainly hydrocarbons and lipid compounds,and a few toxic components.3?Nano-ZnO,nano-TiO2 and nano-Si3N4 were added to wood plastic composites,to prepare nano-reinforced wood plastic composites.The characteristics of nano-ZnO,nano-TiO2 and nano-Si3N4 were used to improve the properties of wood plastic composites,and study the enhancement mechanism.The results show that the mechanical properties of the samples changed significantly after mixing different proportions of bamboo powder,PBS,nano-ZnO,nano-TiO2,nano-Si3N4,and chitosan.The composite material has better mechanical properties when nano-Si3N4 and chitosan were added.When nano-TiO2,nano-Si3N4,and chitosan were used at the same time,which has the greatest impact on the properties of composites.FT-IR and XRD analysis showed that when nano-ZnO,nano-TiO2,nano-Si3N4,and chitosan were added,PBS and bamboo powder could form strong chemical bonds.TGA and DTG analysis showed that the thermal stability of the composite after nano-Si3N4 addition was significantly improved.The results of TD-GC-MS analysis showed that there were mainly hydrocarbons,lipid compounds,some aldehyde-ketone compounds,and a small amount of aromatic compounds in PBS composites,Therefore,the composite volatile gas contains less toxic components.