Department of Chemistry, Princeton University, Princeton, NJ, USA.
ExxonMobil Chemical Company, Baytown, TX, USA.
Nat Chem. 2021 Feb;13(2):156-162. doi: 10.1038/s41557-020-00614-w. Epub 2021 Jan 25.
Closed-loop recycling offers the opportunity to mitigate plastic waste through reversible polymer construction and deconstruction. Although examples of chemical recycling of polymers are known, few have been applied to materials derived from abundant commodity olefinic monomers, which are the building blocks of ubiquitous plastic resins. Here we describe a [2+2] cycloaddition/oligomerization of 1,3-butadiene to yield a previously unrealized telechelic microstructure of (1,n'-divinyl)oligocyclobutane. This material is thermally stable, has stereoregular segments arising from chain-end control, and exhibits high crystallinity even at low molecular weight. Exposure of the oligocyclobutane to vacuum in the presence of the pyridine(diimine) iron precatalyst used to synthesize it resulted in deoligomerization to generate pristine butadiene, demonstrating a rare example of closed-loop chemical recycling of an oligomeric material derived from a commodity hydrocarbon feedstock.
闭环回收提供了通过可逆聚合物构建和解构来减轻塑料废物的机会。虽然聚合物的化学回收的例子是已知的，但很少有应用于来源于丰富的商品烯烃单体的材料，这些单体是无处不在的塑料树脂的构建块。在这里，我们描述了 1,3-丁二烯的[2+2]环加成/齐聚反应，得到了以前未实现的（1，n'-二乙烯基）齐聚环丁烷的远程微观结构。这种材料热稳定，具有源自链端控制的立构规整段，并且即使在低分子量下也表现出高结晶度。将齐聚环丁烷暴露于真空下，并使用用于合成它的吡啶（二亚胺）铁前催化剂，导致解齐聚生成原始丁二烯，证明了一种来自商品碳氢化合物原料的寡聚材料的闭环化学回收的罕见例子。
