Selective Reactivity of Myrcene for Vat Photopolymerization 3D Printing and Postfabrication Surface Modification.

Biosourced materials are gaining interest industrially, but there are still limitations on the library of available materials suitable for advanced manufacturing, especially using photopolymerization-based processing techniques. Terpenes, such as myrcene, are naturally produced materials possessing structural features, specifically alkenes, that avail themselves for such techniques. Free-radical and anionic polymerization techniques were used to explore molecular architecture, such as branching, as well as molecular weight and dispersity on physical properties prior to the production of 3D printing photopolymer resins. The polymyrcene resins were printed into dogbones and mold templates for soft materials. Model reactions with monofunctional thiols were used to demonstrate the potential for postpolymerization and fabrication functionalization, accompanying a physical demonstration where the surface hydrophobicity of polymyrcene could be tuned from superhydrophobic when using an alkyl chain monothiol (greater than 100° water contact angle) to a hydrophilic surface displaying a water contact angle of less than 45° compared with that of the unmodified surface (∼60°). Tunable bulk and surface properties are a unique feature for 3D printing materials and demonstrate the potential of polymyrcene and other biosourced photopolymers to a wide range of research applications.