Bland M H, Peppas N A
Biomedical Materials Laboratory, School of Chemical Engineering, Purdue University, West Lafayette, IN 47907-1283, USA.
Biomaterials. 1996 Jun;17(11):1109-14. doi: 10.1016/0142-9612(96)85912-6.
Polymer networks that can serve as model systems for dental applications were prepared by photopolymerizations of 1,1,1-trimethylolpropane triacrylate, 1,1,1-trimethylolpropane trimethacrylate, 1,1,1-trimethylolethane trimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, Photomer 2028 and Photomer 3015. The UV polymerizations were initiated by 2,2-dimethoxy-2-phenyl-acetophenone. Volume shrinkage was followed over the course of polymerization using a dilatometric technique. Incident light intensities ranged from 1 mW cm-2 to 20 mW cm-2. The effects of monomer structure on % volume shrinkage, including pendant group size, molecular weight between reactive double bonds, and acrylate versus methacrylate monomers were investigated. In addition, the effect of incident light intensity on % volume shrinkage was studied. Typical volume shrinkage varied from 3.5% to 13.5%. The volume shrinkage decreased with increasing monomer rank and increased pendant group size; the shrinkage for methacrylates was less than that for acrylates. Increased incident light intensity resulted in increased shrinkage rate, but not in statistically significant increases of the volume shrinkage. Conversion was calculated from shrinkage data and compared to data from monomer extraction experiments. Results indicate that although double bond conversion is low, conversion of monomer units is significantly higher.
通过1,1,1-三羟甲基丙烷三丙烯酸酯、1,1,1-三羟甲基丙烷三甲基丙烯酸酯、1,1,1-三羟甲基乙烷三甲基丙烯酸酯、乙二醇二甲基丙烯酸酯、三乙二醇二甲基丙烯酸酯、Photomer 2028和Photomer 3015的光聚合反应制备了可作为牙科应用模型系统的聚合物网络。紫外光聚合反应由2,2-二甲氧基-2-苯基苯乙酮引发。使用膨胀计技术在聚合过程中跟踪体积收缩。入射光强度范围为1 mW cm-2至20 mW cm-2。研究了单体结构对体积收缩率的影响，包括侧基大小、反应性双键之间的分子量以及丙烯酸酯与甲基丙烯酸酯单体的影响。此外，还研究了入射光强度对体积收缩率的影响。典型的体积收缩率在3.5%至13.5%之间变化。体积收缩率随着单体等级的增加和侧基大小的增加而降低；甲基丙烯酸酯的收缩率小于丙烯酸酯的收缩率。入射光强度的增加导致收缩率增加，但体积收缩率没有统计学上的显著增加。根据收缩数据计算转化率，并与单体萃取实验的数据进行比较。结果表明，虽然双键转化率较低，但单体单元的转化率明显较高。
