Study On Preparation And Properties Of Silicon-containing ASA Rubber Powder And Its Alloy

Acrylonitrile-styrene-acrylate(ASA)graft copolymer is a class of polymers with excellent weather resistance.Benefiting from the special“core-shell”structure,it is able to play a toughening role as an impact modifier in the alloy materials.However,the impact strength of ASA itself is not high,which limits its wide application.Therefore,it is necessary to improve the impact resistance of ASA itself to meet the higher performance requirements of the material.Based on the Si-O-Si flexible chain molecular structure of organosiloxane with higher bond energy,a series of modified ASA graft copolymers were synthesized by modifying ASA with organosiloxane.The effect of organosiloxane on the properties of ASA was studied,and the toughening effect of modified ASA on plastic alloy was explored.The main research contents and results are as follows.The silicon-poly(n-butyl acrylate)(Si-PBA)latex particles which modified by 3-(trimethoxysilyl)propyl methacrylate(KH570)was prepared by emulsion polymerization.Then a series of siloxane modified acrylonitrile-styrene-acrylate(Si-ASA)grafted polymers were prepared by grafting styrene(St)and acrylonitrile(AN).By analyzing the Si-PBA latex particles size,we optimized the synthetic process of Si-ASA and yield was up to 80%.Subsequently,the structure,morphology and properties of the novel Si-ASA grafted polymers were studied.A series of PMMA/ASA alloy materials with different proportions were prepared via extrusion injection of the blends which composed of the Si-ASA and polymethyl methacrylate(PMMA).The rheological properties,impact properties and tensile properties of the alloy were tested.The results show that the toughening effect of ASA-2(containing 5 wt%KH570)is the most outstanding,and the PMMA/ASA alloy prepared by ASA-2 has the best comprehensive properties and processing fluidity.The properties of the alloy are related to the addition of ASA-2:when the addition is 25%,the impact strength of the alloy is 54.1 k J/m~2,and the impact property up to the peaking;when the addition improved to 35%,the elongation at break of the alloy is 65.4%.In addition,the toughening effect of ASA-3(containing 10 wt%KH570)on PMMA/ASA alloy is second only to ASA-2.A series of PBT/ASA alloy materials were prepared via extrusion injection of the blends which composed of the Si-ASA and polybutylene terephthalate(PBT).The toughening effect of the novel Si-ASA grafted polymer on PBT/ASA alloy was further studied on the basis of the effective toughening effect of the novel Si-ASA grafted polymer on PMMA/ASA alloy.The implication of these results is that ASA-2 and ASA-3 can effectively improve the impact properties of PBT/ASA alloy.The properties of the alloy are related to the addition of ASA-2:when the addition is 20%,the impact property of PBT/ASA alloy is the excellent,and the impact strength is 94.7 k J/m~2;when the addition is 20%,the elongation at break of the alloy reaches the maximum,which is 29.6%,and the toughening effect is the most outstanding.Furthermore,the toughening effect of ASA-3 on PBT/ASA alloy is second only to ASA-2.It is an important segment to further verified the toughening effect of ASA-2 and ASA-3.In summary,Si-ASA grafted polymer with excellent comprehensive properties was successfully prepared in this study,which played an obvious toughening role in the plastic alloy.It is expected to become a kind of impact modifier with excellent properties,and provides a new idea and feasible scheme for the modification of ASA.