Shieh L, Tamada J, Chen I, Pang J, Domb A, Langer R
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge 02139.
J Biomed Mater Res. 1994 Dec;28(12):1465-75. doi: 10.1002/jbm.820281212.
Studies investigating the erosion mechanism of the newly developed poly (fatty acid dimer: sebacic acid) polyanhydride (p:[FAD:SA]) are described. The overall erosion of different monomer compositions of p(FAD:SA) copolymers was examined to determine whether and to what extent copolymer properties affected polymer erosion. Increasing the hydrophobic monomer (FAD) content up to 50 wt% in the copolymer resulted in longer erosion, whereas further increases up to 70 wt% decreased the erosion period. Polymer crystallinity depended on copolymer FAD content. Copolymer degradation was studied by examining anhydride bond hydrolysis using infrared spectroscopy. Much faster hydrolysis was found in p(FAD:SA) 70:30 compared with more crystalline copolymers of higher SA content. Light microscopy indicates the presence of an erosion zone, a distinct area where mass loss occurs. This erosion zone moves from the outside toward the interior of the polymer matrix. It plays an important role in erosion because any water or monomer must diffuse through this eroded layer.
本文描述了对新开发的聚（脂肪酸二聚体：癸二酸）聚酐（p:[FAD:SA]）侵蚀机制的研究。研究了不同单体组成的p(FAD:SA)共聚物的整体侵蚀情况，以确定共聚物性能是否以及在何种程度上影响聚合物侵蚀。将共聚物中疏水单体（FAD）的含量提高到50 wt%会导致侵蚀时间延长，而进一步提高到70 wt%则会缩短侵蚀时间。聚合物的结晶度取决于共聚物中FAD的含量。通过红外光谱检查酸酐键水解来研究共聚物的降解。与SA含量较高的结晶性更强的共聚物相比，p(FAD:SA) 70:30的水解速度要快得多。光学显微镜显示存在一个侵蚀区，即发生质量损失的明显区域。这个侵蚀区从聚合物基质的外部向内部移动。它在侵蚀过程中起着重要作用，因为任何水或单体都必须扩散穿过这个侵蚀层。
