Microwave-Assisted Ultrafast RAFT Miniemulsion Polymerization of Biobased Terpenoid Acrylates

Effect of Microwave-Assisted Curing on Properties of Waterborne Silicone Antifouling Coatings

Waterborne silicone coatings are prepared in this paper by using silicone emulsion as a film-forming material, γ-methacryloxypropyltrimethoxysilane, and dibutyltin dilaurate as a curing agent and a catalyst, respectively. The corresponding coatings are obtained by controlling different microwave times to accelerate the coating curing. The surface morphology, roughness, surface properties, mechanical properties, and antifouling properties of the coating are studied by laser confocal microscope, contact angle measurement, tensile test, marine bacterial attachment test, and benthic diatom adhesion test. Additionally, the action mechanism of microwaves in the curing process of the coatings is also discussed. The results show that the microwave can greatly reduce the curing time of waterborne silicone coating. It can improve the painting efficiency, the surface roughness of the coating, and the mechanical properties of the coatings. The change in roughness increases the contact angle of the coating, reduces the apparent surface energy, and then improves the antifouling performance. For the coating cured by microwave, with the increase in microwave curing time, the water and diiodomethane contact angles of the coating gradually increase, and the surface energy gradually decreases from about 20 mJ/m2 to 10.8 mJ/m2. With the increase in microwave time, the attachment amount of Navicular Tenera gradually decreases, the removal rate gradually increases, and the removal rate of Navicular Tenera in the coating increases from 15.36% to 31.78%. The bacterial removal rate of the coating can be increases from 11.05% to 22.28% after microwave curing. Microwave-assisted curing is helpful in improving the antifouling and self-cleaning performance of waterborne silicone coatings, showing promising potential applications.

Bioderived 4D Printable Terpene Photopolymers from Limonene and β-Myrcene

Green manufacturing and reducing our cultural dependency on petrochemicals have been topics of growing interest in the past decade, particularly for three-dimensional (3D) printable photopolymers where often toxic solvents and reagents have been required. Here, a simple solvent-free, free-radical polymerization is utilized to homo- and copolymerize limonene and β-myrcene monomers to produce oligomeric photopolymers (M_n < 11 kDa) displaying Newtonian, low viscosities (∼10 Pa × s) suitable for thiol-ene photo-cross-linking, yielding photoset materials in a digital light processing (DLP)-type 3D printer. The resulting photosets display tunable thermomechanical properties (poly(limonene) displays elastic moduli exceeding 1 GPa) compared with previous works focusing on monomeric terpenes as well as four-dimensional (4D) shape memory behavior. The utility of such photopolymers for biomedical applications is briefly considered on the premise of the hydrophilic nature (measured by contact angle) as well as their cytocompatibility upon seeding films with macrophages. These terpene-derived, green 4D photopolymers are shown to have promising physical behaviors suitable for an array of manufacturing and 3D printing applications.

Polymer Colloids: Synthesis Fundamentals to Applications

This special issue of Biomacromolecules highlights research from The International Polymer Colloid Group (IPCG), which was founded in 1972 as a forum for the exchange of ideas and emerging research activities for scientists and engineers from both academia and industry who study or use polymer colloids. The increasing relevance of polymeric structures with colloidal dimensions to biomacromolecules research provided the impetus for organizing this special issue. The IPCG is composed of over 120 researchers from over 20 countries who are elected to membership. Activities comprise annual symposia including a biennial International Polymer Colloid Group Research Conference and a semiannual newsletter that incorporates a summary of recent (including unpublished) research results from our members.

Non-thermal microwave effects in radical polymerization of bio-based terpenoid (meth)acrylates

Non-thermal microwave effects are operative for terpenoid acrylates but not for methacrylates, provided that a minimum irradiation power is applied.