Yang J M, You J W, Chen H L, Shih C H
Department of Chemical Engineering, Chang Gung College of Medicine and Technology, Taoyuan, Taiwan, Republic of China.
J Biomed Mater Res. 1996 Summer;33(2):83-8. doi: 10.1002/(SICI)1097-4636(199622)33:2<83::AID-JBM4>3.0.CO;2-H.
The formation of acrylic bone cements upon heating was investigated by differential scanning calorimetry (DSC). The effects of the contents of initiators, accelerator, biocompatibilizer, and crosslinking agents on the rate and the heat of polymerization during DSC heating were studied. The rate and the heat of polymerization (delta H) were characterized by the peak temperature and the area of the DSC exotherm, respectively. It was found that both the rate and heat of polymerization decreased with increasing heating rate. The delta H was increased considerably with increasing benzoyl peroxide (BPO) initiator concentration from 1 to 10% (w/v), whereas the rate of polymerization was reduced significantly. An increase in azobisisobutyronitrile (AIBN) initiator concentration also induced an increase in delta H, but the rate of reaction was not affected considerably. The addition of accelerator promoted the rate of reaction but resulted in a drop in delta H. The rate of polymerization for the system containing BPO initiator was increased quite significantly with the addition of hydroxyethyl methacrylate (HEMA) biocompatibilizer, while the delta H was slightly increased. For the system using AIBN as the initiator, the rate of polymerization was decreased slightly and the delta H dropped significantly with the addition of HEMA. The effect of ethylene glycol dimethacrylate (EGDMA) crosslinking agent was also examined. Polymerization became more rapid with the addition of EGDMA in the bone cement using BPO initiator, while it remained approximately constant for the system using AIBN as the initiator. No systematic change in delta H was observed with the addition of EGDMA in both systems. This study demonstrated that DSC is a potential tool to measure the amount of heat released and also the rate of polymerization for bone cements.
通过差示扫描量热法（DSC）研究了加热时丙烯酸骨水泥的形成。研究了引发剂、促进剂、生物相容性剂和交联剂的含量对DSC加热过程中聚合速率和聚合热的影响。聚合速率和聚合热（ΔH）分别通过DSC放热峰的峰值温度和面积来表征。发现聚合速率和聚合热均随加热速率的增加而降低。随着过氧化苯甲酰（BPO）引发剂浓度从1%（w/v）增加到10%（w/v），ΔH显著增加，而聚合速率显著降低。偶氮二异丁腈（AIBN）引发剂浓度的增加也导致ΔH增加，但反应速率没有受到显著影响。促进剂的加入促进了反应速率，但导致ΔH下降。对于含有BPO引发剂的体系，加入甲基丙烯酸羟乙酯（HEMA）生物相容性剂后，聚合速率显著增加，而ΔH略有增加。对于使用AIBN作为引发剂的体系，加入HEMA后，聚合速率略有下降，ΔH显著下降。还研究了二甲基丙烯酸乙二醇酯（EGDMA）交联剂的作用。在使用BPO引发剂的骨水泥中加入EGDMA后，聚合反应变得更快，而对于使用AIBN作为引发剂的体系，聚合反应速率大致保持不变。在两个体系中加入EGDMA后，未观察到ΔH的系统性变化。本研究表明，DSC是一种测量骨水泥释放热量和聚合速率的潜在工具。
