针对现有环氧类防热涂层韧性差、不耐烧蚀的缺点,设计了一种环氧类防热涂层——TR-48。测试了其基本性能及3-5个批次的典型性能,并与国外现有涂层进行了比较。结果证明:TR-48具有韧性好、强度高、耐烧蚀等特点;其中拉伸强度为8.7-11.2 M...针对现有环氧类防热涂层韧性差、不耐烧蚀的缺点,设计了一种环氧类防热涂层——TR-48。测试了其基本性能及3-5个批次的典型性能,并与国外现有涂层进行了比较。结果证明:TR-48具有韧性好、强度高、耐烧蚀等特点;其中拉伸强度为8.7-11.2 MPa,伸长率为6.8%-12.2%,TG分析800℃残碳率为51%,800℃马弗炉烧蚀5 m in残碳率为38%-47%。利用SEM、DSC表征了涂层的烧蚀过程,发现600-800℃存在烧结反应。利用液氧/煤油发动机和电弧风洞考核试验考核了涂层在高温、高速气流环境下的表现,结果表明该涂层具有较好的抗冲刷及防热性能。展开更多
An epoxy resin based on diglycidyl ether of bisphenol A(epoxy resin E 51)was toughened with a liquid crystalline epoxy resin,4 expoxypropoxy phenyl 4′ epoxypropoxy benzoate(PHBHQ)which presented a Schlieren texture i...An epoxy resin based on diglycidyl ether of bisphenol A(epoxy resin E 51)was toughened with a liquid crystalline epoxy resin,4 expoxypropoxy phenyl 4′ epoxypropoxy benzoate(PHBHQ)which presented a Schlieren texture in the temperature range of 131～94℃ during cooling.A mixed aromatic diamine,4,4′ diaminodiphenylmethane(DDM):4,4′ diaminodiphenylsulfone(DDS):4,4′ diaminodiphenylester(DDE)=5∶2∶1 weight ratio,was used as the curing agent,and the curing conditions were adopted as 100℃/1 h,120℃/2 h,150℃/2 h and 180℃/2 h.The influence of PHBHQ on the properties of final resin systems was investigated.Compared with other toughing agents such as rubbers and thermoplastic resins,PHBHQ can improve the toughness of epoxy resin E 51 greatly without affecting the modulus and thermal resistance.The impact strength of epoxy resin E 51 modified with 50 wt% PHBHQ reached 40.2 kJ/m 2,which was higher than that of pure epoxy resin E 51 system with 23 4 kJ/m 2.The thermal property of toughing epoxy resin systems was tested with dynamic mechanical thermal analysis(DMTA).The results showed that the glass transition temperature increased about 30℃ with only 9 wt% PHBHQ.Wide angle X ray Diffraction(WAXD)was used to characterize the crystalline structure.Two diffraction angles were observed at the 9° and 23°,which showed that the nematic molecular arrangement has been kept during the crosslinking of the toughing system when the reaction was carried out in the thermal stability range of liquid crystalline phase.A two phase structure was observed on the fracture surface by scanning electronic microscopy (SEM).The oriented mesogenic domain which was dispersed in the continuous epoxy matrix can initiate,branch and terminate the cracks and endow toughening epoxy networks with excellent overall properties.展开更多
文摘针对现有环氧类防热涂层韧性差、不耐烧蚀的缺点,设计了一种环氧类防热涂层——TR-48。测试了其基本性能及3-5个批次的典型性能,并与国外现有涂层进行了比较。结果证明:TR-48具有韧性好、强度高、耐烧蚀等特点;其中拉伸强度为8.7-11.2 MPa,伸长率为6.8%-12.2%,TG分析800℃残碳率为51%,800℃马弗炉烧蚀5 m in残碳率为38%-47%。利用SEM、DSC表征了涂层的烧蚀过程,发现600-800℃存在烧结反应。利用液氧/煤油发动机和电弧风洞考核试验考核了涂层在高温、高速气流环境下的表现,结果表明该涂层具有较好的抗冲刷及防热性能。
文摘An epoxy resin based on diglycidyl ether of bisphenol A(epoxy resin E 51)was toughened with a liquid crystalline epoxy resin,4 expoxypropoxy phenyl 4′ epoxypropoxy benzoate(PHBHQ)which presented a Schlieren texture in the temperature range of 131～94℃ during cooling.A mixed aromatic diamine,4,4′ diaminodiphenylmethane(DDM):4,4′ diaminodiphenylsulfone(DDS):4,4′ diaminodiphenylester(DDE)=5∶2∶1 weight ratio,was used as the curing agent,and the curing conditions were adopted as 100℃/1 h,120℃/2 h,150℃/2 h and 180℃/2 h.The influence of PHBHQ on the properties of final resin systems was investigated.Compared with other toughing agents such as rubbers and thermoplastic resins,PHBHQ can improve the toughness of epoxy resin E 51 greatly without affecting the modulus and thermal resistance.The impact strength of epoxy resin E 51 modified with 50 wt% PHBHQ reached 40.2 kJ/m 2,which was higher than that of pure epoxy resin E 51 system with 23 4 kJ/m 2.The thermal property of toughing epoxy resin systems was tested with dynamic mechanical thermal analysis(DMTA).The results showed that the glass transition temperature increased about 30℃ with only 9 wt% PHBHQ.Wide angle X ray Diffraction(WAXD)was used to characterize the crystalline structure.Two diffraction angles were observed at the 9° and 23°,which showed that the nematic molecular arrangement has been kept during the crosslinking of the toughing system when the reaction was carried out in the thermal stability range of liquid crystalline phase.A two phase structure was observed on the fracture surface by scanning electronic microscopy (SEM).The oriented mesogenic domain which was dispersed in the continuous epoxy matrix can initiate,branch and terminate the cracks and endow toughening epoxy networks with excellent overall properties.
