快速成型自由基光固化树脂的研究

Study on free-radical resins used in stereolithography

对以光引发剂IHT-PI910和TPO与丙烯酸酯树脂组成的紫外光固化树脂体系的固化特性进行了研究,测定了不同光引发剂树脂体系的临界曝光量和透射深度系数,抽提测定了树脂体系曝光时间与凝胶含量的关系,并用FTIR分析了体系中C=C双键的转化率.结果表明:对光引发剂IHT-PI910的树脂体系,曝光量对数与固化厚度的线性相关性差,透射深度系数非常数,随曝强度增加而变大;对光引发剂TPO的树脂体系,曝光量对数与固化厚度有好的线性相关性,测得体系的临界曝光量和透射深度系数分别为2.65mJ/cm2和0.24mm;光引发剂IHT-PI910比TPO对紫外辐射更敏感,但TPO可得到高的凝胶率和C=C转化率.

A epoxy-acrylate resin was incorporated with photoinitiator IHT-PI 910 or TPO and the curing features of two UV-curable resins were investigated. The critical exposure energy and UV penetrating coefficients of the resins were measured; the gel contents and the conversion of the C=C double bonds were monitored. For IHT-PI 910 system,there is no linear relationship between exposure lnE and cured thickness; the coefficient of UV penetration is not constant and increases with increasing exposure energy. For photoinitiator TPO system,the cured thickness is linearly proportional to exposure lnE,the critical exposure energy and the UV penetrating coefficient were calculated to be 2.65 mJ/cm2,and 0.24mm,respectively.Though IHT-PI 910 is more UV sensitive for initiation it achieved lower gel content and C=C conversion at high exposure.