Fundamental Research On The Application Of 200 ? Winding Polytriazole Composites

The case,a critical component for the Solid Rocket Motor(SRM),bears such complex loads as force and heat while the SRM working.And the weight of case should be light.Carbon fiber reinforced epoxy resin composites by winding process has been widely used as the case of SRM with high performance due to the properties of high strength and lightweight for the carbon fiber reinforced epoxy resin composites and the advantages of high specific strength,high specific stiffness,designability,fatigue resistance,impact resistance,etc for the advanced ploymer composite materials.However,it is difficult for epoxy resin composites to be used as the novel SRM case working at higher temperature for the reason of poor heat resistant of epoxy resin.The composites,which use the traditional heat resistant resin such as cyanate ester resin,bismaleimide resin and other resins as matrix,are hard to be manufactured by winding processing because the matrix resin is generally cured at high temperature.The properties of heat resistant PTA5 polytriazole resin and its composites are studied in this paper to meet the need of high-temperature resistant composites by winding process for SRM case.And the possibility of the PTA5 polytriazole resin composites by winding process which are used at the temperature of 200^oC is discussed.Firstly,the chemical structure of the PTA5 polytriazole resin was characterized and the properties were analyzed.The chemical structure of the PTA5 polytriazole resin was characterized by molecular weight test and infrared spectroscopy analysis.The curing reaction mechanism of the PTA5 polytriazole resin was investigated by the results of rheological test,DSC tests and in-situ infrared spectroscopy.The heat resistance of the PTA5polytriazole resin was studied by TG test of cured PTA5 polytriazole resin.The curing process of PTA5 polytriazole resin was initially determined.Secondly,the manufacture processing of carbon fiber reinforced polytriazole resin composite was optimized.The infiltration between carbon fiber and polytriazole resin was characterized by contact angle test and the result was explained by infrared spectroscopy analysis of the carbon fiber sizing agent.The T800/PTA5prepreg and T300 carbon fiber cloth/PTA5 prepreg were prepared and the properties were analyzed.The effects of curing process on the glass transition temperature T_g,thermophysical constant,interlaminar shear strength,flexural strength and other properties of T800/PTA5composite laminates and T300 carbon fiber cloth/PTA5 composite laminates were investigated.According to the correlation between the high temperature performance of PTA5polytriazole resin composite and the curing temperature,the curing process of the composite was optimized.Finally,the NOL rings and?150mm vessels of T800/PTA5 composite by winding process were prepared and the properties were tested and analyzed.The results indicated that the molecular weight of PTA5 polytriazole resin is small with the number average molecular weight of 501.There are two functional groups,azide and alkynyl,in the molecular chain.There are also benzene ring and silicon atoms which contribute to heat resistance.The curing reaction of PTA5 polytriazole resin can be divided into two steps.The first step is mainly 1,3-dipolar cycloaddition reaction of terminal alkynyl and azide at40?130 ^oC,and the next step is mainly 1,3-dipolar cycloaddition reaction of internal alkynyl and azide and the self-polymerization of excess internal alkynyl at 180?230 ^oC.When the maximum curing temperature is 200 ^oC,the T_d5of cured resin is 333 ^oC,and it presents a good heat resistance.The infiltration of carbon fiber and polytriazole resin is good because there are functional groups—OH and C=C in the carbon fiber sizing agent,which can form a good interface with PTA5 polytriazole resin.The breaking strength of T800 carbon fiber reinforced PTA5 polytriazole resin prepreg is 5250 MPa,which meets the requirements of winding process.For unidirectional T800/PTA5 composite laminate prepared by winding process,the high temperature performance of interlaminar shear strength is increased with the increase of maximum curing temperature.T_gof the composite laminate is 282.4 ^oC,showing a higher thermal stability and good mechanical property when the maximum curing temperature is 200 ^oC.For T300 carbon fiber cloth/PTA5 composite laminate prepared by laying process,the interlaminar shear strength is increased with the increase of maximum curing temperature,but the flexural strength is not increased greatly.The heat insulation performance of composite laminate is good with the thermal conductivity of 0.577 W·m^-1·K^-1and mechanical properties are better,when the maximum curing temperature is 200 ^oC.At 200 ^oC,the interlaminar shear strength and tensile strength of T800/PTA5 composite NOL ring are29.8 MPa and 2010 MPa with the high-temperature performance retention rate more than70%and heat resistance is good,when the maximum curing temperature is 200 ^oC.The burst pressure and PV/W,the vessel characteristic coefficient,of?150 mm vessels for the T800/PTA5 composite are 46.67 MPa and 53.4 km respectively,showing excellent performances of the?150mm vessel.