| Nylon 10T(PA10T)is a new type of high temperature resistant polyamide material,which has excellent performance and achieves certain advantages in environmental protection.So it has wide application prospect.The glass fibers are cheap and acquiring easily,and glass fiber reinforced nylon thermoplastic resin has rich theoretical basis and technical support.At the same time,with the demand of the performance for engineering plastics boost in electronics,automotive and other industries,glass fiber reinforced PA10 T composites has good prospect for development in the future.However,nylon 10 T is sensitive to temperature and easy to be affected by heating and oxygen,there are little reports on the aging of glass fiber reinforced PA10 T composites in the domestic and overseas.In this paper,PA10 T was used as matrix material,short glass fiber reinforced PA10T(SGF/PA10T)and long glass fiber reinforced PA10T(LGF/PA10T)composites were prepared by two different processing methods,correspondingly.The effects of thermal-oxidative aging on the structure and properties of this two glass fiber reinforced PA10 T composites were systematically studied by artificial accelerated aging method at the temperatures of 160,200 and 240°C.The mechanical properties,crystallization behavior,morphology,dynamic mechanical properties,thermal stability and other aspects of the SGF/PA10 T and LGF/PA10 T composites were discussed roundly,and the service life of the two kinds of composites were predicted by an easy and quick method.In the thermal-oxidative aging condition,the mechanical properties of SGF/PA10 T and LGF/PA10 T composites decreased,which were affected by temperature and aging time,the retention rates of mechanical properties of this two kinds of composites at low aging temperature and short aging time were higher than that of composites aged at a long aging time and high temperature.And the debonding between glass fiber and matrix was the main reason that reduced the mechanical properties of composite materials.The study on crystallization properties showed that with the increase of aging time,the crystallinity of SGF/PA10 T and LGF/PA10 T composites decreased and the initial crystallization temperature(Toneset)and the crystallization peak temperature(Tc)increased,indicating that PA10 T molecular chains were broken under the condition of heating and oxygen,the molecular weight distribution would become wide.The analysis on the dynamic mechanical properties showed that with thermal-oxidative aging intensifies,whether long or short glass fiber reinforced PA10 T composites,the damping properties reduced and the adhesion between glass fiber and PA10 T matrix was weakened.However,during the whole thermal-oxidative aging process,both the storage modulus and the glass transition temperature(Tg)will increase in SGF/PA10 T and LGF/PA10 T samples,indicating that the thermal-oxidative aging also resulted in the cross-linking between PA10 T molecules and improved the rigidity of the sample.Overall,in the thermal-oxidative aging process of samples,there existed two phenomena,included the degradation of PA10 T molecular chain and crosslinking between molecules,but the molecular chain fracture,and the interface adhesion properties between glass fiber and PA10 T matrix reduced were the dominant factors to effect the thermal-oxidative aging properties of specimens.The tensile strength was carried out as the index to predict the lifetime of SGF/PA10 T and LGF/PA10 T composites.At 150°C,the calculated life of the two kind of samples were 86 days and 101 days respectively,and found that there existed a characteristic of aging temperature,when the aging temperature was lower the characteristic temperature,anti-aging ability of LGF/PA10 T was better than that of SGF/PA10 T specimen sample,and above this characteristic temperature,SGF/PA10 T,will get a better anti-aging ability. |
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