3D-Printed, Ultrastretchable Polychloroprene Elastomers via Thiol-ene Photopolymerization

Area of Science:

• Polymer Chemistry
• Materials Science
• Additive Manufacturing

Background:

• Polychloroprene is a versatile synthetic elastomer valued for chemical stability and mechanical strength.
• Current processing relies heavily on thermal curing agents, limiting advanced manufacturing techniques.
• Developing alternative curing methods is crucial for expanding polychloroprene applications.

Purpose of the Study:

• To report the first successful ultraviolet (UV) curing of polychloroprene networks.
• To investigate the potential of UV-cured polychloroprene for three-dimensional (3D) printing.
• To characterize the mechanical and thermal properties of the novel polychloroprene materials.

Main Methods:

• Utilized thiol-ene click chemistry for UV-initiated cross-linking of dissolved polychloroprene.
• Varied concentrations and architectures of thiol cross-linkers during UV curing.
• Characterized material properties using photorheology, tensile testing, and differential scanning calorimetry.
• Demonstrated 3D printing feasibility using a digital light processing (DLP) system.

Main Results:

• Achieved ultrahigh extensibility in cross-linked polychloroprene networks, with strains at break approaching 2000%.
• UV-cured materials retained thermal properties similar to uncured polychloroprene.
• Successfully 3D printed complex objects with mechanical properties comparable to conventionally processed rubber (2.4 MPa tensile stress, 1200% strain at break).

Conclusions:

• UV curing via thiol-ene chemistry offers a viable alternative to thermal processing for polychloroprene.
• This advancement enables additive manufacturing of high-performance polychloroprene components.
• The developed material platform provides exceptional mechanical resilience and preserves intrinsic polychloroprene characteristics.