2022-10-13 テキサス大学オースチン校(UT Austin)
A new plastic-like material developed by researchers at The University of Texas at Austin can be manipulated to be soft and stretchy or hard and rigid with only the application of a catalyst and visible light.
12種類の触媒を試した結果、モノマーに添加して可視光を照射すると、既存の合成ゴムに見られるような半結晶性ポリマーになる触媒を発見した。光が当たった部分はより硬く、光が当たらない部分は柔らかく伸びる性質が保たれていた。
この反応は室温で行われ、モノマーと触媒は市販されており、実験では安価な青色LEDを光源として使用した。また、反応にかかる時間は1時間未満で、有害廃棄物の使用も最小限に抑えられているため、迅速かつ安価で、エネルギー効率も高く、環境にも優しいプロセスである。
<関連情報>
- https://news.utexas.edu/2022/10/13/smart-plastic-material-is-step-forward-toward-soft-flexible-robotics-and-electronics/
- https://www.science.org/doi/10.1126/science.add6975
光化学的結晶性パターニングによる高分子マルチマテリアル Polymeric multimaterials by photochemical patterning of crystallinity
Adrian K. Rylski,Henry L. Cater,Keldy S. Mason,Marshall J. Allen,Anthony J. Arrowood,Benny D. Freeman,Gabriel E. Sanoja,Zachariah A. Page
Science Published:13 Oct 2022
DOI: 10.1126/science.add6975
A reactive way to make a composite
Blending different materials to form a composite is a way to tune properties to achieve something not possible in a single material. However, it can be challenging to mix or pattern dissimilar materials. Rylski et al. developed a way to produce multimaterials by patterning a strong domain within an elastic domain. They used a dual-catalyst system that polymerizes cis-polycyclooctene in the dark but forms trans-polycyclooctene when exposed to light. This approach led to a polyoctenamer with cohesively connected viscoelastic (soft) and semicrystalline (hard) domains and provided the ability to spatially control the properties of the polymer. —MSL
Abstract
An organized combination of stiff and elastic domains within a single material can synergistically tailor bulk mechanical properties. However, synthetic methods to achieve such sophisticated architectures remain elusive. We report a rapid, facile, and environmentally benign method to pattern strong and stiff semicrystalline phases within soft and elastic matrices using stereo-controlled ring-opening metathesis polymerization of an industrial monomer, cis-cyclooctene. Dual polymerization catalysis dictates polyolefin backbone chemistry, which enables patterning of compositionally uniform materials with seamless stiff and elastic interfaces. Visible light–induced activation of a metathesis catalyst results in the formation of semicrystalline trans polyoctenamer rubber, outcompeting the formation of cis polyoctenamer rubber, which occurs at room temperature. This bottom-up approach provides a method for manufacturing polymeric materials with promising applications in soft optoelectronics and robotics.