A random ethylene–butene copolymer was irradiated with high ionizing energy in environments with different oxygen concentration. The non-isothermal crystallization process of the materials was studied by differential scanning calorimetry. When the polymer was exposed to radiation under free oxygen ambient, the temperature and the crystallinity degree decreased almost linearly with dose because chain-linking reaction prevails. On the contrary, those thermal parameters increased in the material obtained by irradiating the copolymer in environments with oxygen availability where chain scission reactions dominate. It was also found that, at equivalent irradiation dose, the crystallization rates decreased with the dose at a given cooling rate and with the reduction in oxygen content. The parameters obtained from different applied models also confirm the tendencies observed for the experimental variables.

在氧浓度不同的环境中，以高电离能辐照了无规乙烯-丁烯共聚物。通过差示扫描量热法研究了材料的非等温结晶过程。当聚合物在自由氧环境下暴露于辐射下时，温度和结晶度几乎随剂量呈线性下降，因为盛行链连接反应。相反，那些热参数在通过链断裂反应占主导的具有氧可利用性的环境中辐照共聚物而获得的材料中增加。还发现在相同的辐照剂量下，结晶速率随着在给定冷却速率下的剂量以及氧含量的降低而降低。