Synthesis and Formulation of Photocurable Resins Possessing Polyethylene Glycol and POSS, and Preparation of Their Related Nanocomposites

Design and synthesis of self-curable solutions containing polyethylene glycol (PEG) and polyhedral oligomeric silsesquioxane (POSS) is a simple and economical method to enhance the physical and mechanical properties of biodegradable PEG.

First POSS nanoparticles were treated with acryloyl chloride (AC) to obtain POSS-AC nano-powder. In another reaction, PEG was copolymerized with fumaryl chloride to prepare polyethylene glycol fumarate (PEGF). POSS-AC was subsequently dispersed in PEGF matrix in 1 and 2% (wt) in the presence and absence of N-vinyl pyrrolidone as a reactive diluent. The obtained slurries were photocured by blue light irradiation using camphorquinone as photoinitiator. The crystal structure, dispersion quality, crosslink ability, mechanical, thermal and thermomechanical characteristics of the prepared nanocomposites as well as crosslinked neat PEGF were studied by XRD, TEM, equilibrium swelling, tensile, TGA and DMTA tests, respectively.

The XRD pattern of nanocomposites did not show any sharp peak related to the aggregation and agglomeration of the nanoparticles. TEM pictures revealed good dispersion of POAA-AC nanoparticles with mean diameter within 10-50 nm range. Furthermore, the presence of POSS-AC and reactive diluent led to an increase in the Tg of cured PEGF (as a blank system) from -16°C to a value in the range of -13 to -3°C, gel content from 45% to 62-84%, storage modulus from 1.6 GPa to 2.2-3.3 GPa, maximum decomposition temperature from 395 °C to 408-432°C, and Young's modulus from 0.46 MPa to 1.2-1.6 MPa. As a result, the nanocomposites designed in this study exhibited good mechanical properties and fast curing which would be considered as potential candidates for tissue engineering and biomedical applications.