形状记忆聚合物特性及在生物医学领域应用中的优势

Properties and biomedical applications of shape memory polymers

背景:形状记忆聚合物是一类新型功能材料,在生物医疗领域的潜在应用前景逐步受到人们的重视。目的:综述形状记忆聚合物的特性及其应用现状。方法:通过Springer Link数据库、中国期刊全文数据库等检索数据库搜索近年来有关形状记忆聚合物的研究内容。结果与结论:形状记忆聚合物是一种新型的智能材料,与形状记忆合金及形状记忆陶瓷相比,它具有密度低、质量轻、成本低、形状回复率高、形状记忆温度易于调节、易于着色、形变量大、赋形容易且易于在预定温度下被激发等优点。特别是形状记忆聚氨酯,具有结构-性能易于控制、形状记忆温度选择范围宽(-30-70℃)、生物相容性良好等优点,因而在生物医学领域具有广阔的应用前景。但目前已开发的形状记忆聚合物普遍综合性能不够理想,如聚降冰片烯虽然形变回复力大、形变速度快、回复精度高,但形状回复温度可调节范围小,相对分子质量太大,分子链较长,成型加工较为困难等。另外,多数形状记忆聚合物形状回复力小,回复速度较慢,回复精度低,重复记忆效果不够理想,机械强度和化学耐久性还不够好。因此,利用分子设计和材料改性技术优化其形状记忆功能,努力提高其综合性能,是今后形状记忆聚合物研究和发展的关键。

BACKGROUND：Shape memory polymer is a new type of functional material. The applications of shape memory polymers in the biomedical field have increasingly been paid close attention. OBJECTIVE： To summarize the characteristics and applications of shape memory polymers. METHODS： SpringerLink and China Journal Ful text Database were searched for articles related to shape memory polymers. RESULTS AND CONCLUSION： As a new type of inteligence material, shape memory polymers have lots of advantages compared with shape memory aloy and shape memory ceramics, such as low density, light weight, low cost, high shape-recovery rate, easy to regulate the shape memory temperature, to dye, to shape and to be stimulated under expected switch temperature. Especialy for polyurethane, the structure-property relationships are extremely easy to control, the shape memory temperature can be set in a wide range from-30℃ to 70℃, and it has the biocompatibility. Due to these, shape memory polymers have great potentials in applications of biomedical engineering. But the comprehensive properties of the developed shape memory polymers are not satisfactory. For example, the polynorbornene has big recovery stress, fast recovery velocity and high recovery precision, but its relative molecular mass is very big, the molecularchain is long, and processing is difficult.Furthermore, most of shape memory polymers have smal recovery stress, slow recovery velocity, low recovery precision and unsatisfied repeat memory effect. The key problems for shape memory polymers include optimization of the function of shape memory and improvement of the comprehensive properties based on the technologies of molecular design and material modification.