Preparation Of Polyamide6/Polybutylene Terephthalate Alloy And Impact Of Flame Retardant Additive On Its Properties

Polyamide 6?PA6?and Polybutylene terephthalate?PBT?are two kind of excellent engineering plastics,PA6 has excellent resistance to chemical corrosion,wear resistance and self-lubricating with deficiencies like high water absorption and shrinkage of the formation,these weaknesses seriously limit its application.PBT has low water absorption and dimensional stability,but it is easy to break down in high temperature and humidity environment and poor impact resistance.The PA6/PBT alloys are prepared by melt blending and can achieve complementary advantages of the two kinds of polymer,which has wide application prospect in automobile and electronic appliances.However,the poor compatibility of PA6 and PBT result the poor performance of PA6/PBT alloy and the alloy is composed of flammable macroolecule material,and these cause big problems.Based on the above problems,the PA6/PBT alloys are prepared by melt blending,and flame retardant modification of PA6/PBT alloys are carried out by adding additive flame retardant.First,the PA6/PBT alloys are prepared with different PBT contents and effects are investigated.The results show that the mechanical properties and water absorption decreased,and the melt index became smaller with the increase of PBT content.The POE-g-MAH and POE-g-GMA are added to PA6/PBT in a mass ratio of 1:1 as the complex compatibility agent and their properties are evaluated.The results show that the addition of the composite compatibilizer can improve the shortness of the notched impact performance of the alloy,but the tensile strength and the flexural strength decrease.When the amount of the compatibilizer is 15 phr,the notched impact strength of the alloy is 15.5KJ/m²,the water absorption and melt index of the alloy decreased slightly with the addition of the compatibilizer,but the DSC shows that the melting temperature and the crystallization temperature also decrease.On the basis of PA6/PBT alloys,three kinds of flame retardant systems which are composed of DBDPE and Sb₂O₃,MCA and BDP complex system and MPP and carbon forming agent are prepared and studied.The results show that the flame retardant system composed of DBDPE and Sb₂O₃ and MCA and BDP are both effective flame retardants for PA6/PBT alloys,which can significantly improve the flame retardancy,but the amount of DBDPE and Sb₂O₃ produce amount of smoke.And MPP and the composition of the composition of the complex system can not effectively improve the PA6/PBT alloys flame retardant properties.Considering the choice of MCA and BDP complex flame retardant system materials,the overall performance is better.