Preparation And Properties Of Glass Fiber Reinforced Flame Retardant Semi-aromatic High Temperature Resistant Polyamide PA10T/66

Polyamide has excellent mechanical strength,corrosion resistance and chemical resistance,and can be widely used in automobiles,aerospace,electronic appliances and other fields.Aliphatic polyamide molecular chains are regular,soft,and have high crystallinity,but generally have low melting points;fully aromatic polyamides have high melting points,high strength,and high modulus,but the melting point is higher than the decomposition temperature and it cannot be processed by melting;semi-aromatic polyamide is a combination of the two,and its melting point is higher,above 300°C,the comprehensive performance is also excellent.Semi-aromatic polyamide PA10T is a bio-based semi-aromatic polyamide,the synthetic monomer decanediamine is extracted from castor oil,which is a renewable energy source,and meets the requirements of environmental protection.The melting point of PA10T is very close to the decomposition temperature,which brings difficulties to the late processing modification molding.PA10T/66 is a copolymer modification product based on PA10T,which reduces the melting point and widens the processing window.In order to guarantee the environment and personal safety,the market also has higher and higher requirements on the flame retardant properties of materials,the manufacture of flame retardant polyamide materials is also required by the market.This topic aims at preparing flame retardant and enhanced modified composite materials for PA10T/66.Processing method modified by blending,magnesium hydroxide,glass fiber and zinc borate and PA10T/66 are melt extruded in a twin screw extruder.The composite materials of different systems were obtained,and the mechanical,thermal and flame retardant properties of PA10T/66 are explored,the results show that:（1）Magnesium hydroxide can play a flame-retardant role.Thermogravimetric test results show that the decomposition of the composite material is composed of two steps,the initial decomposition temperature is reduced.The magnesium hydroxide decomposes in advance,which plays a role in protecting the matrix,and the residual carbon rate increases.However,the residual carbon is sparse and its combustion is quite complete.The flame retardant efficiency of magnesium hydroxide is low,and the composite can reach V-0 level when it is added to the 50%,which has a great impact on the mechanical properties of the composite material.（2）After adding glass fiber,the mechanical properties of the composite material are greatly improved,the strength modulus becomes larger,and the plasticity decreases;the flame retardant grade of the composite material with a glass fiber content of 30%can reach V-0,at this point the oxygen index reaches 36%;glass fiber has no effect on the melting temperature and initial decomposition temperature of the composite material.The final decomposition temperature of the composite material increases slightly,the amount of residual carbon continues to increase,and the maximum decomposition rate decreases.The residual carbon is strong and the density is high.（3）The non-crystalline process of the composite material was analyzed by the Mo method,and the F（T）value andαvalue were calculated.It was found that when the glass fiber content is small,the crystallization process can be accelerated,instead,when the glass fiber content is large,especially in the late crystallization,the crystallization rate drops.（4）Partially replacing magnesium hydroxide with zinc borate,the mechanical properties of the composite material have improved,and the comprehensive mechanical properties are optimal at 4%content;the flame retardant performance has not decreased,the initial decomposition temperature has increased,and the final decomposition temperature has little effect.The maximum degradation rate k₁ is increased,and the amount of residual carbon is slightly increased,which indicates that zinc borate and magnesium hydroxide have a synergistic effect on the flame retardant effect of the composite material.