当前位置: X-MOL 学术J. Am. Chem. Soc. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Mechanically Gated Degradable Polymers
Journal of the American Chemical Society ( IF 15.0 ) Pub Date : 2020-01-15 , DOI: 10.1021/jacs.9b13359
Yangju Lin 1 , Tatiana B Kouznetsova 1 , Stephen L Craig 1
Affiliation  

Degradable polymers are desirable for the replacement of con-ventional organic polymers that persist in the environment, but they often suffer from the unintentional scission of the degradable functionalities on the polymer backbone, which diminishes polymer properties during storage and regular use. Herein, we report a strategy that combats unintended degrada-tion in polymers by combining two common degradation stimuli-mechanical and acid triggers-in an "AND gate" fashion. A cyclobutane (CB) mechanophore is used as a me-chanical gate to regulate an acid-sensitive ketal that has been widely employed in acid degradable polymers. This gated ketal is further incorporated into the polymer backbone. In the pres-ence of acid trigger alone, the pristine polymer retains its backbone integrity, and delivering high mechanical forces alone by ultrasonication degrades the polymer to an apparent limiting molecular weight of 28 kDa. The sequential treatment of ultrasonication followed by acid, however, leads to a further 11-fold decrease in molecular weight to 2.5 kDa. Experimental and computational evidence further indicate that the ungated ketal possesses mechanical strength that is commensurate with the conventional polymer backbones. Single molecule force spectroscopy (SMFS) reveals that the force necessary to activate the CB molecular gate on the timescale of 100 ms is approximately 2 nN.

中文翻译:

机械门控可降解聚合物

可降解聚合物是替代在环境中持久存在的传统有机聚合物的理想选择,但它们通常会遭受聚合物主链上可降解官能团的意外断裂,这会降低聚合物在储存和正常使用过程中的性能。在此,我们报告了一种策略,该策略通过以“与门”方式结合两种常见的降解刺激(机械和酸触发)来对抗聚合物中的意外降解。环丁烷 (CB) 机械载体用作机械门来调节已广泛用于酸可降解聚合物的酸敏感缩酮。该门控缩酮进一步结合到聚合物主链中。在单独的酸引发剂存在下,原始聚合物保持其骨架完整性,单独通过超声处理传递高机械力会使聚合物降解到 28 kDa 的表观极限分子量。然而,超声处理和酸处理的顺序处理导致分子量进一步降低 11 倍至 2.5 kDa。实验和计算证据进一步表明,非门控缩酮具有与传统聚合物主链相当的机械强度。单分子力谱 (SMFS) 表明,在 100 ms 的时间尺度上激活 CB 分子门所需的力约为 2 nN。实验和计算证据进一步表明,非门控缩酮具有与传统聚合物主链相当的机械强度。单分子力谱 (SMFS) 表明,在 100 ms 的时间尺度上激活 CB 分子门所需的力约为 2 nN。实验和计算证据进一步表明,非门控缩酮具有与传统聚合物主链相当的机械强度。单分子力谱 (SMFS) 表明,在 100 ms 的时间尺度上激活 CB 分子门所需的力约为 2 nN。
更新日期:2020-01-15
down
wechat
bug