HTPE弹性体玻璃化温度研究

Study on glass transition temperature of HTPE elastomer

针对BDNPF/A增塑的HTPE推进剂玻璃化转变温度高、低温性能不足,难以满足宽温使用要求的问题,研究了HTPE预聚物中结构单元比例(EO/THF)、相对分子质量、交联点间平均相对分子质量以及增塑剂种类对HTPE弹性体玻璃化转变温度(Tg)的影响。结果表明,HTPE预聚物中结构单元比例(EO/THF)和相对分子质量对其Tg值均存在影响,随着EO含量的升高或预聚物相对分子质量的增大,Tg值移向高温;网络交联密度对HTPE弹性体玻璃化温度影响较大,交联点间平均相对分子质量与玻璃化转变温度呈二次函数关系,即Tg=AM^2r-BMr,-C,固化参数(Rt)较交联度(ρ)对玻璃化转变温度的影响更显著;DNPH增塑剂对HTPE弹性体的增塑效率优于BDNPF/A增塑剂,采用BDNPF/A增塑剂和DNPH增塑剂复配可改善HTPE弹性体的综合性能。

Aiming at problems of high glass transition temperature and poor low temperature performance of HTPE propellantwith BDNPF/A plasticizer,which are hard to meet wide temperature range requirements,the influence of HTPE prepolymer struc-tural unit(EO/THF)ratio,HTPE relative molecular mass,cross-link average relative molecular mass and plasticizer variety onHTPE elastomer glass transition temperature(Tg)were studied in this paper.Results show that:(1)The ratio of structural units(EO/THF)and relative molecular mass of HTPE prepolymer have influence on theTgvalue.With the increase of EO content orrelative molecular mass of prepolymer,theTgvalue moves towards high temperature;(2)The network crosslinking density has agreat influence on the glass transition temperature of HTPE elastomer,and the relationship between the average relative molecularmass and the glass transition temperature is quadratic function:Tg=AM^2r-BMr,-C.The effect of curing parameters(Rt)onTgisgreater than that of crosslinking degree(ρ);(3)The plasticizing efficiency of DNPH plasticizer to HTPE elastomer is better than thatof BDNPF/A plasticizer.The comprehensive properties of HTPE elastomer can be improved by using compound plasticizer com-posed of BDNPF/A plasticizer and DNPH plasticizer.