羟基磷灰石晶种对α-磷酸钙骨水泥水化的影响

EFFECTS OF HYDROXYAPATITE SEEDS ON THE HYDRATION OF α-CALCIUM PHOSPHATE CEMENT

在α -磷酸钙骨水泥体系中分别添加用沉淀法合成的结晶完整的羟基磷灰石晶种 (HAp)和由机械 -化学法制备的结晶程度较差的羟基磷灰石晶种 (HAm)。研究两种晶种对骨水泥固化时间、抗压强度和产物微观结构的影响。结果表明 :添加晶种可以降低产物成核所需克服的势垒、促进成核、大幅度缩短骨水泥的固化时间。未加晶种的骨水泥的固化时间为 30min ,加入质量分数 4%HAm 和质量分数 4%HAp 晶种的骨水泥 ,其固化时间分别为 11min和 15min。同时 ,添加晶种能有效抑制晶粒生长 ,有利于抗压强度的提高。添加HAm 和HAp 晶种的骨水泥 。

Calcium phosphate bone cement (CPC) based on α_tricalcium phosphate (α-TCP) was seeded with perfect crystalline hydroxyapatite (HA_p) synthesized by precipitate method, or with poor crystalline hydroxyapatite (HA_m) prepared by mechanical-chemical method. The effects of seeding on the setting time, the compressive strength and the microstructure of the CPC were studied. The results show that the seeds appear to reduce the setting time and increase the compressive strength. The HA seeds can decrease the potential barrier for nucleation and therefore accelerate nucleation in the product since it is structurally similar to the hydration production. The setting time of the unseeded CPC is 30 min, while the setting time of the CPC containing 4% (in mass)HA_m and 4%(in mass) HA_p is 11 min and 15 min, respectively. Addition of HA seeds can inhibit the overgrowth of the plate_like particles to form a structure with fine particles or network configuration distributed in dense matrix, which led to a higher compressive strength.