Photodegradable branched polyethylenes from carbon monoxide copolymerization under benign conditions

Abstract

Small amounts of in-chain keto groups render polyethylene (PE) photodegradable, a desirable feature in view of environmental plastics pollution. Free-radical copolymerization of CO and ethylene is challenging due to the formation of stable acyl radicals which hinders further chain growth. Here, we report that copolymerization to polyethylenes with desirable low ketone content is enabled in dimethyl carbonate organic solvent or under aqueous conditions at comparatively moderate pressures <350 atm that compare favorable to typical ethylene polymerization at 2000 atm. Hereby, thermoplastic processable materials can be obtained as demonstrated by injection molding and tensile testing. Colloidally stable dipersions from aqueous polymerizations form continuous thin films upon drying at ambient conditions. Extensive spectroscopic investigation including 13 C labeling provides an understanding of the branching microstructures associated with keto groups. Exposure of injection molded materials or thin films to simulated sunlight under sea-like conditions results in photodegradation.

Extending Alkenes’ Value Chain to Functionalized Polyolefins

“…The other perspective is incorporating a low amount of in-chain keto groups to render photodegradable polyethylene as an environmentally friendly sustainable thermoplastic while retaining its characteristic properties [53,54].…”

Polyethylene Materials with In-Chain Ketones from Catalytic Copolymerization

“…Their composition was calculated from the van-der-Waals equation for CO and the equation of state for ethylene. 10,11 Figure S2. Flow diagram (left) and photo of the reactor setup (right) used for the copolymerization of ethylene with carbon monoxide.…”

“…Non-labeled ketones in spatial proximity shift their IR resonance frequencies gradually from 1716 cm -1 for isolated C=O groups embedded in polyethylene to 1690 cm -1 for alternating polyketones. 10 This corresponds to resonances of isolated 13 C=O groups at 1678 cm -1 whereas 13 C-labeled alternating polyketones give rise to a resonance at 1652 cm -1 according to equation S3. These predicted ATR-IR shifts correlate with those found experimentally for copolymers prepared with 13 CO comonomer (cf.…”

A one‐step method to manufacture biodegradable poly (butylene adipate‐co‐terephthalate) bead foam parts

“…Global environmental pollution caused by waste plastic is getting worse rapidly 1 . The exponential growth of global waste plastics, who are resistant to decomposition and maintain nondegradation for a long time due to inactive hydrocarbon chains, 2 has been made pollution widespread distribution, not only land 3 but also the atmosphere, 4 forest, 5 and even the ocean 6 . Hundreds of millions of tons of waste plastics not only occupy a large number of lands, 7 destroy landform, 8 and vegetation 9 but also produce plastic particles, fibers, and films 10 which seriously harm human health, 11 induce cytotoxicity, 12 damage organs 13 and tissues, 14 and cause multiple health hazard effects 15 .…”