Gresser J D, Hsu S H, Nagaoka H, Lyons C M, Nieratko D P, Wise D L, Barabino G A, Trantolo D J
Cambridge Scientific, Inc., Belmont, Massachusetts 02178, USA.
J Biomed Mater Res. 1995 Oct;29(10):1241-7. doi: 10.1002/jbm.820291011.
A resorbable bone cement was formulated from N-vinyl-2-pyrrolidinone (VP), the unsaturated polyester poly(propylene fumarate) (PPF), and the inorganic filler tribasic calcium phosphate (hydroxy apatite). Cure, initiated by benzoyl peroxide and accelerated by N,N-dimethyl-p-toluidine, resulted in the formation of VP crosslinks between polyester chains. During cure the cement hardened from a viscous moldable putty to a rigid structure with a shore D hardness of 50-60. The purpose of this study was to determine the fractions of PPF and VP incorporated into the crosslinked structure. Dissolution of the cured cement in water followed by extraction of the residue in tetrahydrofuran indicated that over 90% of the PPF was crosslinked over the range of PPF/VP ratios explored, but that the fraction of VP used in formation of crosslinks depended linearly on the PPF/VP ratio. Kinetic analysis of these data suggests that k'pp/kpf (the reactivity ratio) was approximately 2.0 where k'pp is the rate constant for the addition of VP radical to VP monomer leading to formation of poly(vinyl pyrrolidone), and kpf is for the addition of VP radical to PPF unsaturation.
一种可吸收骨水泥由N-乙烯基-2-吡咯烷酮（VP）、不饱和聚酯聚富马酸丙二醇酯（PPF）和无机填料磷酸三钙（羟基磷灰石）配制而成。由过氧化苯甲酰引发并由N，N-二甲基对甲苯胺加速的固化过程导致聚酯链之间形成VP交联。在固化过程中，骨水泥从粘性可模塑油灰硬化为肖氏D硬度为50-60的刚性结构。本研究的目的是确定掺入交联结构中的PPF和VP的比例。将固化后的骨水泥溶解于水中，然后用四氢呋喃萃取残留物，结果表明，在所研究的PPF/VP比例范围内，超过90%的PPF发生了交联，但用于形成交联的VP比例与PPF/VP比例呈线性关系。对这些数据的动力学分析表明，k'pp/kpf（反应活性比）约为2.0，其中k'pp是VP自由基加成到VP单体上形成聚乙烯基吡咯烷酮的速率常数，kpf是VP自由基加成到PPF不饱和键上的速率常数。
