This paper utilizes a soap-free emulsion polymerization process to prepare microgel particles that can swell in response to in-situ generated acid in photocurable resin. By controlling the type and concentration of end-capping agents and the content of cross-linking agents, pH-responsive microgel particles with significantly increased particle size in acidic environments are synthesized. The strong protonic acid generated by the photoacid upon exposure to ultraviolet light can reduce the pH of the UV-curable resin, leading to an enlargement of the particle size. This can compensate for the volume shrinkage of the resin, ultimately reducing shrinkage stress. The research findings indicate that the addition of 5 wt% of pH-responsive particless and 2 wt% of photoacid to the UV-curable resin results in a reduction of approximately 40% in shrinkage stress and shrinkage rate.

本文利用无皂乳液聚合工艺制备微凝胶颗粒，该颗粒可以响应光固化树脂中原位产生的酸而膨胀。通过控制封端剂的类型和浓度以及交联剂的含量，合成了在酸性环境下粒径显着增加的pH响应性微凝胶颗粒。光酸在紫外光照射下产生的强质子酸可以降低紫外光固化树脂的pH值，导致粒径增大。这可以补偿树脂的体积收缩，最终减少收缩应力。研究结果表明，在紫外线固化树脂中添加 5 wt% 的 pH 响应颗粒和 2 wt% 的光酸，可使收缩应力和收缩率降低约 40%。