Hydrophilic graft modification of a commercial crystalline polyolefin

Transition-Metal-Catalyzed Silylation and Borylation of C-H Bonds for the Synthesis and Functionalization of Complex Molecules

The functionalization of C-H bonds in organic molecules containing functional groups has been one of the holy grails of catalysis. One synthetically important approach to the diverse functionalization of C-H bonds is the catalytic silylation or borylation of C-H bonds, which enables a broad array of downstream transformations to afford diverse structures. Advances in both undirected and directed methods for the transition-metal-catalyzed silylation and borylation of C-H bonds have led to their rapid adoption in early-, mid-, and late-stage of the synthesis of complex molecules. In this Review, we review the application of the transition-metal-catalyzed silylation and borylation of C-H bonds to the synthesis of bioactive molecules, organic materials, and ligands. Overall, we aim to provide a picture of the state of art of the silylation and borylation of C-H bonds as applied to the synthesis and modification of diverse architectures that will spur further application and development of these reactions.

100th Anniversary of Macromolecular Science Viewpoint: Toward Catalytic Chemical Recycling of Waste (and Future) Plastics

The current global materials economy has long been inefficient due to unproductive reuse and recycling efforts. Within the wider materials portfolio, plastics have been revolutionary to many industries but they have been treated as disposable commodities leading to their increasing accumulation in the environment as waste. The field of chemistry has had significant bearing in ushering in the current plastics industry and will undoubtedly have a hand in transforming it to become more sustainable. Existing approaches include the development of synthetic biodegradable plastics and turning to renewable raw materials in order to produce plastics similar to our current petrol-based materials or to create new polymers. Additionally, chemists are confronting the environmental crisis by developing alternative recycling methods to deal with the legacy of plastic waste. Important emergent technologies, such as catalytic chemical recycling or upcycling, have the potential to alleviate numerous issues related to our current and future refuse and, in doing so, help pivot our materials economy from linearity to circularity.

The post-modification of polyolefins with emerging synthetic methods

This Perspective highlights the present state of polyolefin post-modification research, especially concerning recently developed C–H functionalization chemistry. Remaining challenges and emerging strategies within the field have also been discussed.

Thermoplastic elastomers derived from menthide and tulipalin A

Renewable ABA triblock copolymers were prepared by sequential polymerization of the plant-based monomers menthide and α-methylene-γ-butyrolactone (MBL or tulipalin A). Ring-opening transesterification polymerization of menthide using diethylene glycol as an initiator gave α,ω-dihydroxy poly(menthide) (HO-PM-OH), which was converted to α,ω-dibromo end-functionalized poly(menthide) (Br-PM-Br) by esterification with excess 2-bromoisobutyryl bromide. The resulting 100 kg mol(-1) Br-PM-Br macroinitiator was used for the atom transfer radical polymerization of MBL. Four poly(α-methylene-γ-butyrolactone)-b-poly(menthide)-b-poly(α-methylene-γ-butyrolactone) (PMBL-PM-PMBL) triblock copolymers were prepared containing 6-20 wt % PMBL, as determined by NMR spectroscopy. Small-angle X-ray scattering, differential scanning calorimetry, and atomic force microscopy experiments supported microphase separation in the four samples. The mechanical behavior of the triblocks was investigated by tensile and elastic recovery experiments. The tensile properties at both ambient and elevated temperature show that these materials are useful candidates for high-performance and renewable thermoplastic elastomer materials.