School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, P. R. China.
College of Chemistry, Zhengzhou University, Zhengzhou 450001, P. R. China.
ACS Appl Mater Interfaces. 2023 Apr 12;15(14):18300-18310. doi: 10.1021/acsami.2c23317. Epub 2023 Mar 29.
Polyurethane (PU) is a widely used polymer material that will age under prolonged exposure to ultraviolet (UV) light, shortening the service life. Several methods have been used to prepare the anti-UV PU, including adding nonreactive anti-UV additives, functional fillers, and biological antioxidant molecules. However, the nonreactive anti-UV additives may migrate during long-term use, the functional fillers may damage the mechanical properties and seriously reduce the light transmittance of the sample, and the biological antioxidant molecules will inevitably color the sample. To solve these problems, in this work, a benzotriazole UV absorber (Chiguard R-455) was introduced into the PU molecular chains by in situ polymerization to prepare the nonmigrating intrinsic anti-UV PU sample with high performance and colorless transparency. The anti-UV PU samples exhibit light transmittance of over 88% in the visible range and superior mechanical properties with tensile strength higher than 65 MPa and elongation at break higher than 900%. After 24 h UV irradiation (200 W, 365 nm), the tensile strength and elongation at break of pure PU sample are significantly reduced to only 8.9 and 15.8% of the original one, respectively. On the contrary, the addition of Chiguard R-455 will endow the PU sample with excellent anti-UV performance. After 24 h UV irradiation, the tensile strength (67.2 ± 1.6 MPa) and elongation at break (917.4 ± 30.0%) of PU-0.5% (the content of Chiguard R-455 is only 0.5 wt %) have changed little compared with the sample without irradiation (67.4 ± 3.5 MPa and 919.4 ± 26.5%). Additionally, the anti-UV mechanism of the PU sample is systematically studied. This work provides a feasible method for preparing colorless, transparent, high-performance, nonmigrating intrinsic UV-shielding PU samples, which can be used as a UV light-shielding material in various fields with visible and aesthetic requirements, such as protection fields and wearable products.
聚氨基甲酸酯（PU）是一种广泛使用的聚合物材料，在长时间暴露于紫外（UV）光下会老化，从而缩短其使用寿命。为了制备抗 UV 的 PU，人们已经采用了几种方法，包括添加非反应性抗 UV 添加剂、功能性填料和生物抗氧化分子。然而，非反应性抗 UV 添加剂在长期使用过程中可能会迁移，功能性填料可能会破坏样品的机械性能，并严重降低其透光率，而生物抗氧化分子不可避免地会使样品着色。为了解决这些问题，在这项工作中，作者通过原位聚合将苯并三唑型 UV 吸收剂（Chiguard R-455）引入到 PU 分子链中，制备出高性能、无色透明的不可迁移的本征抗 UV PU 样品。该抗 UV PU 样品在可见光范围内的透光率超过 88%，具有优异的机械性能，拉伸强度高于 65 MPa，断裂伸长率高于 900%。经过 24 h 的 UV 照射（200 W，365 nm）后，纯 PU 样品的拉伸强度和断裂伸长率分别显著降低至原始值的 8.9%和 15.8%。相比之下，添加 Chiguard R-455 会赋予 PU 样品优异的抗 UV 性能。经过 24 h 的 UV 照射后，PU-0.5%（Chiguard R-455 的含量仅为 0.5 wt%）的拉伸强度（67.2 ± 1.6 MPa）和断裂伸长率（917.4 ± 30.0%）与未辐照的样品（67.4 ± 3.5 MPa 和 919.4 ± 26.5%）相比几乎没有变化。此外，作者还系统地研究了 PU 样品的抗 UV 机制。这项工作为制备无色透明、高性能、不可迁移的本征 UV 屏蔽 PU 样品提供了一种可行的方法，可将其用作具有可见和美学要求的各个领域的 UV 遮光材料，例如防护领域和可穿戴产品。
