Aldehyde End-Capped Degradable Polyethylenes From Hydrogen-Controlled Ethylene/CO Copolymerization.

Area of Science:

• Polymer Chemistry
• Materials Science
• Catalysis

Background:

• Polyolefin plastics lack inherent degradability.
• Introducing in-chain functional groups, like ketones, can enhance polymer degradability.
• Controlling molecular weight and chain ends in copolymerization remains challenging.

Purpose of the Study:

• To develop a method for producing degradable polyethylene with in-chain ketones.
• To achieve hydrogen-controlled copolymerization of ethylene and carbon monoxide.
• To enable tunable molecular weights and specific chain endgroups.

Main Methods:

• Utilized late transition metal catalysts for ethylene/carbon monoxide copolymerization.
• Employed hydrogen as a chain transfer agent to control molecular weight.
• Analyzed polymer structure and endgroups to confirm non-alternating insertion and functionalization.

Main Results:

• Successfully synthesized linear polyethylene with 1.0-9.3 mol% in-chain keto groups.
• Achieved tunable molecular weights ranging from 43 to 195 kDa using hydrogen.
• Demonstrated strictly non-alternating (>99%) copolymer structure with aldehyde endgroups.
• Incorporated keto groups retained bulk properties while enabling photodegradation.

Conclusions:

• Hydrogen-controlled non-alternating copolymerization of ethylene and carbon monoxide is feasible.
• This method yields degradable polyethylene with tailored molecular weights and functional endgroups.
• The resulting keto-polyethylene exhibits enhanced susceptibility to photodegradation.