Choi Soon Mo, Lee Soo Young, Lee Sunhee, Han Sung Soo, Shin Eun Joo
Research Institute of Cell Culture, Yeungnam University, 280 Daehak-ro, Gyeongsan 38541, Republic of Korea.
Department of Polymer Science & Engineering, Pusan National University, Busandaehak-ro 63 Beon-gil 2, Busan 46241, Republic of Korea.
Polymers (Basel). 2023 Mar 20;15(6):1541. doi: 10.3390/polym15061541.
The development of waterborne polyurethane (WPU) has been stimulated as an alternative to solvent-based polyurethanes due to low-VOC alternatives and reduced exposure to solvents. However, their relatively low mechanical performance and degradation have presented challenges in their wide application. Here, we developed environmentally-friendly bio polyol-based WPU nanocomposite dispersions and films, and presented the optimal process conditions for their manufacture. Additionally, the condition was established without using harmful catalysts or ethyl methyl ketone (MEK) during the polymerization. Moreover, regenerated cellulose nanoparticles (RCNs) were employed as natural chain-extenders in order to improve the biodegradability and mechanical performances of the nanocomposite films. The RCNs have a lower crystallinity compared to cellulose nanocrystals (CNCs), allowing them to possess high toughness without interfering with the elastomeric properties of polyurethane. The prepared CWPU/RCNs nanocomposite films exhibited high toughness of 58.8 ± 3 kgf∙mm and elongation at break of 240 ± 20%. In addition, depending on the molar ratio of NCO/OH, the polyurethane particle size is variously controlled from 70 to 230 nm, enabling to fabricate their dispersions with various transmittances. We believe that our findings not only open a meaningful path toward green elastomers with biodegradability but provides the design concept for bio-elastomers in order to develop industrial elastomers with mechanical and thermal properties.
由于低挥发性有机化合物替代物以及减少了对溶剂的接触，水性聚氨酯（WPU）的发展受到推动，成为溶剂型聚氨酯的替代品。然而，它们相对较低的机械性能和降解性在其广泛应用中带来了挑战。在此，我们开发了基于生物多元醇的环保型WPU纳米复合分散体和薄膜，并给出了其制造的最佳工艺条件。此外，在聚合过程中不使用有害催化剂或甲乙酮（MEK）的条件也已确立。而且，采用再生纤维素纳米颗粒（RCNs）作为天然扩链剂，以提高纳米复合薄膜的生物降解性和机械性能。与纤维素纳米晶体（CNCs）相比，RCNs具有较低的结晶度，使其在不干扰聚氨酯弹性性能的情况下具有高韧性。制备的CWPU/RCNs纳米复合薄膜表现出58.8±3千克力·毫米的高韧性和240±20%的断裂伸长率。此外，根据NCO/OH的摩尔比，聚氨酯粒径可在70至230纳米之间进行不同控制，从而能够制备具有不同透光率的分散体。我们相信，我们的研究结果不仅为具有生物降解性的绿色弹性体开辟了一条有意义的道路，而且为生物弹性体提供了设计理念，以便开发具有机械和热性能的工业弹性体。
