現行的壓克力系骨水泥大多以PMMA/MMA為粉、液體的主要材料，而此配方的聚合硬化過程的高放熱量會使整個系統反應溫度高於人體所能承受的溫度，進而破壞周圍的組織以及影響骨水泥尺寸安定性。本實驗室將液體中MMA單體成份以不同比例置換成BMA單體，BMA單體因其有較低的聚合熱(BMA：398J/g、MMA：544J/g)，所以能減少聚合時的放熱量並降低聚合溫度。本研究紀錄溫度對時間變化，並以DSC測量其放熱量，並進行機械測試，探討將單體由MMA換成BMA的影響，並在理想的轉化率下找到一個最佳配方。結果顯示，BMA的添加確實能降低骨水泥的放熱量，而且也能有效降低骨水泥的最大聚合溫度以及提升骨水泥硬化時間，但是會降低儲存模數的值。在不嚴重影響機械性質且又能降低聚合反應溫度的考量下，從實驗結果判斷，在BMA置換MMA的比例方面建議以不超過50％為準。 The main material of solid and liquid of most acrylic bone cement is PMMA and MMA. The great heat of polymerization of this formula cause a high temperature. This temperature is too high to human. It might contribute to the trauma, and consequently lead to prosthesis loosening. Our laboratory replace MMA in the liquid with BMA in variably proportions. Because BMA has a lower heat of polymerization (BMA is 398 J/g, MMA is 544 J/g), it decreases the heat that generate during polymerizing and the max temperature. This study recorded the variation of temperature with time. Besides, we measured the heat of polymerization and mechanical properties. We discussed the effect upon replace MMA with BMA. Furthermore, found out the optimum formula with ideal conversion.The results indicated that replace MMA in the liquid with BMA in variably proportions could reduce exothermic amount. Also, it could reduce the Tmax and raise setting time. But the store modulus was decreased. Under not influencing mechanical properties and can reduce the temperature of polymerization made decision form the results. BMA proportion of replacing MMA is proposed for not exceeding 50%.
