熱塑性聚氨酯彈性體(Thermoplastic Polyurethane,簡稱TPU)具有高強度、高伸長率、高彈性以及優異的耐磨、耐油、耐低溫等…..特性。同其他的高分子材料一樣,TPU市場與應用領域不斷擴大,發展迅速。由於其耐熱與耐候性較差,容易造成使用上的困擾與限制。TPU的耐熱、耐候老化性,可透過添加穩定劑如:紫外光吸收劑、光穩定劑、抗氧化劑、鈦白粉來改善,從而滿足不同的應用要求。TPU産品(特別是芳香族TPU)在自然環境中長期使用,在受到光(特別是紫外光)、熱、氧和水分的影響下,其外觀和機械性能會有大幅度的降低,甚至失去實用價值。改善TPU耐候性的方法主要有下列兩種。一、添加助劑:在TPU中添加合適的光穩定劑、抗氧化劑和熱穩定劑來達到改善黃變之目的。然而在添加這些穩定劑時要有適當的選擇與搭配。以避免添加劑彼此間所産生的抵銷作用。二、遮蔽作用:在TPU中添加碳黑、鈦白粉、碳酸鈣或色料,不僅對其色變和老化裂解有遮蔽作用,還可以降低成本,達到TPU耐候之效果。本次研究主題為TPU添加紫外線吸收劑、光穩定劑與抗氧化劑,利用射出成型技術與耐候性之探討,尋求適用於TPU之耐黃變劑。
Thermoplastic polyurethane elastomers (Thermoplastic Polyurethane, TPU) have high strength, good elongation ratio, and high elasticity, outstanding wearing resistant, oil resistant, bearing the low temperature and etc. TPU markets and applications expand dramatically. However, worse heat resistant and weathering resistance limited the use. To improve heat resistant and weathering resistant of TPU, stabilizers are the best choice, such as UV absorbers, hindered amine light stabilizers (HALS), antioxidants, and titanium oxide. TPU (especially aromatic TPU) could decrease mechanical property and lose commercial value under natural environment for long period of time, for example light (especially ultraviolet light), heat, oxygen, and moisture. There are two major ways to improve TPU weathering resistance. First, you can add different kinds of additives for TPU such as light stabilizers, antioxidants, and heat stabilizers to prevent discoloration or yellowing. However, these stabilizers must have some concerns to prevent conflicting performance. Beside, you can also use color materials for shielding. You can add carbon black, titanium oxide, calcium carbonate, or other pigment in TPU. This way can provide shielding effect, prevent discoloration and the ageing effect, and reduce the cost. This research subject is to seeking suitable UV absorbers, HALS, and antioxidants for TPU to improve weathering resistant by injection molding applications.