A facile one step route that introduces functionality to polymer powders for laser sintering.

Laser Sintering (LS) is a type of Additive Manufacturing (AM) exploiting laser processing of polymeric particles to produce 3D objects. Because of its ease of processability and thermo-physical properties, polyamide-12 (PA-12) represents ~95% of the polymeric materials used in LS. This constrains the functionality of the items produced, including limited available colours.

Synthesis of core-shell polymer particles in supercritical carbon dioxide iterative monomer addition.

A new, robust methodology for the synthesis of polystyrene-poly(methyl methacrylate) (PS-PMMA) core-shell particles using seeded dispersion polymerisation in supercritical carbon dioxide is reported, where the core-shell ratio can be controlled predictably manipulation of reagent stoichiometry. The key development is the application of an iterative addition of the MMA shell monomer to the pre-prepared PS core. Analysis of the materials with differing core-shell ratios indicates that all are isolated as single particle populations with distinct and controllable core-shell morphologies.

Photo-Responsivity Improvement of Photo-Mobile Polymers Actuators Based on a Novel LCs/Azobenzene Copolymer and ZnO Nanoparticles Network.

The efficiency of photomobile polymers (PMP) in the conversion of light into mechanical work plays a fundamental role in achieving cutting-edge innovation in the development of novel applications ranging from energy harvesting to sensor approaches. Because of their photochromic properties, azobenzene monomers have been shown to be an efficient material for the preparation of PMPs with appropriate photoresponsivity. Upon integration of the azobenzene molecules as moieties into a polymer, they act as an engine, allowing fast movements of up to 50 Hz.

Influence of structure and solubility of chain transfer agents on the RAFT control of dispersion polymerisation in scCO.

Reversible addition-fragmentation chain transfer (RAFT) dispersion polymerisation of methyl methacrylate (MMA) is performed in supercritical carbon dioxide (scCO) with 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT) present as chain transfer agent (CTA) and surprisingly shows good control over PMMA molecular weight. Kinetic studies of the polymerisation in scCO also confirm these data. By contrast, only poor control of MMA polymerisation is obtained in toluene solution, as would be expected for this CTA which is better suited for acrylates.