Covalent Adaptable Networks with Associative Siloxane Exchange Enabled by Amide‐Based Internal Catalysis: Designing for Reprocessability and Extrudability by Increasing the Cross‐Link Density DOI Creative Commons
Nathan S. Purwanto, Tong Wang, Xiaoyang Liu

и другие.

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 9, 2025

Abstract Replacing non‐recyclable thermosets with covalent adaptable networks (CANs) that recover cross‐link density after reprocessing will reduce waste and contribute to a circular polymer economy. Many CANs undergoing associative dynamic exchange require catalysis. External catalysis often leads harmful effects, e.g., increased creep, accelerated material aging, catalyst leaching. Herein, internally catalyzed siloxane chemistry is demonstrated resulting from amides covalently linked through alkyl chains siloxanes. Small‐molecule studies show the formation of products reaction two amide‐containing molecules. From rubbery plateau modulus, each siloxane‐exchange‐based CAN exhibits temperature‐invariant, or nearly so, characteristic CANs. The length in siloxane‐containing monomer tunes network density. Cross‐link recovery achieved, required time temperature decreasing increasing Stress relaxation also faster dynamics reprocessability arise because second order (i.e., cross‐linker) concentration. Capitalizing on this, melt extrusion highest demonstrated, achieving same extruded compression‐molded Using identical conditions, next‐highest not extrudable.

Язык: Английский

Polypropylene Covalent Adaptable Networks with Full Cross-Link Density Recovery after Reprocessing: Development by Free-Radical Reactive Processing with Resonance-Stabilized, Aromatic Disulfide Cross-Linkers DOI
Yen-Wen Huang, Mathew Suazo, Stephanie M. Barbon

и другие.

ACS Macro Letters, Год журнала: 2025, Номер unknown, С. 341 - 348

Опубликована: Март 5, 2025

A single-step method that produces percolated, dynamic covalent cross-links integrated into the PP homopolymer has not been previously demonstrated. Here, we synthesized adaptable networks (CANs) from polypropylene (PP) homopolymers using 180 °C, radical-based, reactive processing with a free-radical initiator, dicumyl peroxide (DCP), and resonance-stabilized, aromatic disulfide cross-linkers, one methacrylate-based another phenyl acrylate-based. Both cross-linkers yielded when reactively processed at 4 wt % relatively high molecular weight (MW) (melt flow index (MFI) = 12) DCP. The acrylate-based cross-linker also other studied DCP/cross-linker concentrations low MW (MFI 35). Notably, our highest cross-link density CAN exhibited full recovery of after three reprocessing steps by compression molding; within experimental uncertainty melt extrusion.

Язык: Английский

Процитировано

2
Next-generation vitrimer composites for future mobility: Balancing sustainability and functionality – A perspective DOI

Jinhyeok Kang,

Changwoo Nam

European Polymer Journal, Год журнала: 2025, Номер unknown, С. 113967 - 113967

Опубликована: Май 1, 2025

Язык: Английский

Процитировано

0
Reprocessable Polypropylene Covalent Adaptable Networks via Free-Radical Reactive Processing with Vinyl Aromatic Additives DOI
Yen-Wen Huang, Mathew Suazo, John M. Torkelson

и другие.

Macromolecules, Год журнала: 2025, Номер unknown

Опубликована: Апрель 23, 2025

Язык: Английский

Процитировано

0
Covalent Adaptable Networks with Associative Siloxane Exchange Enabled by Amide‐Based Internal Catalysis: Designing for Reprocessability and Extrudability by Increasing the Cross‐Link Density DOI Creative Commons
Nathan S. Purwanto, Tong Wang, Xiaoyang Liu

и другие.

Advanced Functional Materials, Год журнала: 2025, Номер unknown

Опубликована: Май 9, 2025

Abstract Replacing non‐recyclable thermosets with covalent adaptable networks (CANs) that recover cross‐link density after reprocessing will reduce waste and contribute to a circular polymer economy. Many CANs undergoing associative dynamic exchange require catalysis. External catalysis often leads harmful effects, e.g., increased creep, accelerated material aging, catalyst leaching. Herein, internally catalyzed siloxane chemistry is demonstrated resulting from amides covalently linked through alkyl chains siloxanes. Small‐molecule studies show the formation of products reaction two amide‐containing molecules. From rubbery plateau modulus, each siloxane‐exchange‐based CAN exhibits temperature‐invariant, or nearly so, characteristic CANs. The length in siloxane‐containing monomer tunes network density. Cross‐link recovery achieved, required time temperature decreasing increasing Stress relaxation also faster dynamics reprocessability arise because second order (i.e., cross‐linker) concentration. Capitalizing on this, melt extrusion highest demonstrated, achieving same extruded compression‐molded Using identical conditions, next‐highest not extrudable.

Язык: Английский

Процитировано

0