Kampangsat Sirasit, Kajornprai Todsapol, Tangjatuporn Warakarn, Suppakarn Nitinat, Trongsatitkul Tatiya
School of Biomedical Innovation Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
School of Polymer Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Polymers (Basel). 2024 Jul 7;16(13):1941. doi: 10.3390/polym16131941.
Thermo-responsive, biocompatible polyurethane (PU) with shape memory properties is highly desirable for biomedical applications. An innovative approach to producing wound closure strips using shape memory polymers (SMPs) is of significant interest. In this work, PU composed of polycaprolactone (PCL) and 1,4-butanediol (BDO) was synthesized using two-step polymerization. Palm oil (PO) was added to PU for enhancing the Young's modulus of the PU beyond the set criterion of 130 MPa. It was found that PU had the ability to crystallize at room temperature and the segments of individual PCL and BDO polyurethanes crystallized separately. The crystalline domains and hard segment of PU greatly affected the tensile properties. The reduction of crystalline domains by the addition of PO and deformation at the higher melting temperature of the crystalline PCL polyurethane phase improved the shape fixity and shape recovery ratios. The new irreversible phase, raised from the permanent deformation upon stretching at the between melting temperature of the crystalline PCL and BDO polyurethanes of 70 °C, resulted in a decrease in shape fixity ratio after the first thermomechanical stretching-recovering cycles. The demonstration of PU as a wound closure strip showed its efficiency and potential until the surgical wound healed.
具有形状记忆特性的热响应性生物相容性聚氨酯（PU）在生物医学应用中极具吸引力。一种使用形状记忆聚合物（SMP）生产伤口闭合条的创新方法备受关注。在这项工作中，采用两步聚合法合成了由聚己内酯（PCL）和1,4 - 丁二醇（BDO）组成的PU。向PU中添加棕榈油（PO）以将PU的杨氏模量提高到超过130 MPa的设定标准。研究发现，PU在室温下具有结晶能力，且各个PCL和BDO聚氨酯链段分别结晶。PU的结晶域和硬段对拉伸性能有很大影响。通过添加PO减少结晶域以及在结晶PCL聚氨酯相的较高熔点温度下进行变形，提高了形状固定率和形状回复率。在70°C的结晶PCL和BDO聚氨酯的熔点之间拉伸时，由永久变形产生的新的不可逆相导致在第一次热机械拉伸 - 恢复循环后形状固定率降低。PU作为伤口闭合条的演示表明，在手术伤口愈合之前，它具有有效性和潜力。
