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就自制的稜状和针状两种结晶状态的三聚甲醛进行了固态辐射聚合,制得特性粘数为0.8和K_(222)值力3.4％/分(未酯化的)的聚合物,经酯化后,可压制成膜。 在不同剂量率下研究了聚合转化率与辐照时间的关系,当累积剂量在 2×10~5拉特之前,聚合转化率与剂量呈线性关系,随后转化率出现一极限值(74％以上)。聚合物的特性粘数随剂量的增加而减小。在所研究的剂量范围内(4.1—89拉特/秒)聚合初速率与剂量率呈线性关系。剂量率对聚合物的特性粘数影响不大。 在-78℃到65℃温度范围内进行了温度对聚合速率影响的试验,在0℃以下时不聚合,接近熔点时聚合速率最快,超过熔点(62℃)时,则几乎不聚合。单体的结晶状态及晶体的大小对聚合速率有较大的影响。
Solid-state radial polymerization of trimellitic acid in both prismatic and needle-like crystalline states was carried out to prepare a polymer having an intrinsic viscosity of 0.8 and a K 222 force of 3.4% / min (unesterified) After esterification, can be pressed into a film. The relationship between polymerization conversion and irradiation time was studied at different dose rates. When the cumulative dose was 2 × 10 ~ 5 LAT, there was a linear relationship between the polymerization conversion and the dose, and then a limit of the conversion (above 74% ). The intrinsic viscosity of the polymer decreased with increasing dose. The initial rate of polymerization was linearly proportional to the dose rate over the range of doses studied (4.1-89 lash / sec). The dose rate has little effect on the intrinsic viscosity of the polymer. The effect of temperature on the rate of polymerization was tested at a temperature in the range of -78 ° C to 65 ° C without polymerization at or below 0 ° C. The rate of polymerization approached melting point at the melting point was fastest and beyond the melting point (62 ° C). The crystalline state of the monomer and the size of the crystal have a greater impact on the polymerization rate.