Institute for Biomedical Technology and Technical Medicine and Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
Acta Biomater. 2012 Oct;8(10):3576-85. doi: 10.1016/j.actbio.2012.06.004. Epub 2012 Jun 9.
Poly(trimethylene carbonate) (PTMC) macromers with molecular weights (M(n)) between 1000 and 41,000 g mol(-1) were prepared by ring opening polymerization and subsequent functionalization with methacrylate end groups. Flexible networks were obtained by radical photo-crosslinking reactions of these macromers. With increasing molecular weight of the macromer the networks obtained showed increasing swelling ratios in chloroform and decreasing glass transition temperatures, reaching a constant value of approximately -18°C, which is close to that of linear high molecular weight PTMC. For all prepared networks the creep resistance was high. However, the molecular weight of the macromer strongly influenced the tensile properties of the networks. With increasing molecular weight of the macromer the E-modulus of the networks decreased from 314 MPa (lowest M(n)) to 5 MPa (highest M(n)), while their elongation at break continuously increased, reaching a very high value of 1200%. The maximum tensile strength values of the networks were found to first decrease with increasing M(n), but to increase again at values above approximately 10,000gmol(-1), at which the networks started to show rubber-like behavior. The toughness (area under the stress-strain curves, W) determined in tensile testing experiments, in tear propagation experiments, and in suture retention strength measurements showed that PTMC networks prepared from the higher molecular weight macromers (M(n)>10,000 g mol(-1)) were tenacious materials. The mechanical properties of these networks compare favorably with those of linear high molecular weight PTMC and well-known elastomeric materials like silicone rubber (poly(dimethylsiloxane)) and natural latex rubber. Additionally they also compare well with those of native blood vessels, which may be of importance in the use of these materials for the tissue engineering of small diameter blood vessels.
聚(三亚甲基碳酸酯)(PTMC)大分子单体的分子量(M(n))在 1000 到 41000gmol(-1)之间，是通过开环聚合和随后的甲基丙烯酸酯端基官能化制得的。这些大分子单体的自由基光交联反应得到了柔性网络。随着大分子单体分子量的增加，在氯仿中得到的网络的溶胀比增加，玻璃化转变温度降低，达到约-18°C 的恒定值，接近线性高分子量 PTMC 的玻璃化转变温度。所有制备的网络都具有较高的抗蠕变性。然而，大分子单体的分子量强烈影响网络的拉伸性能。随着大分子单体分子量的增加，网络的 E 模量从 314MPa(最低 M(n))降低到 5MPa(最高 M(n))，而其断裂伸长率不断增加，达到 1200%的非常高的值。网络的最大拉伸强度值最初随 M(n)的增加而降低，但在约 10000gmol(-1)以上的值再次增加，此时网络开始表现出橡胶状行为。在拉伸试验、撕裂传播试验和缝线保持强度测量中确定的韧性(应力-应变曲线下的面积，W)表明，由较高分子量大分子单体(M(n)>10000gmol(-1))制备的 PTMC 网络是坚韧的材料。这些网络的力学性能与线性高分子量 PTMC 以及硅橡胶(聚二甲基硅氧烷)和天然乳胶橡胶等知名弹性体材料相当。此外，它们也与天然血管相当，这可能对这些材料在小直径血管组织工程中的应用很重要。
