Morphology and viscoelastic properties of UV cured-polyurethane acrylate/silicon carbide nanocomposites
- PDF / 2,045,780 Bytes
- 11 Pages / 595.276 x 790.866 pts Page_size
- 23 Downloads / 211 Views
ORIGINAL RESEARCH
Morphology and viscoelastic properties of UV cured‑polyurethane acrylate/silicon carbide nanocomposites Davood Ghanbari1 · Behzad Shirkavand Hadavand1 · Malihe Pishvaei1 Received: 22 April 2020 / Accepted: 26 September 2020 © Iran Polymer and Petrochemical Institute 2020
Abstract The viscoelastic properties of semi-conductive UV cured urethane acrylate/silicon carbide nanocomposites (UV-PUA/SiC) containing 0.1, 0.3, 0.6, 1, 3, and 5% (wt) of SiC are studied. Scanning electron microscopy (SEM) was employed to examine the state of the spatial distribution of SiC particles in the matrix. In conjunction with the electron microscopy technique, dynamic mechanical thermal analysis (DMTA) was employed as an indirect tool for the microstructure characterization and evaluation of the network heterogeneity and cross-link density of the nanocomposites. The influence of SiC nanoparticles on the storage modulus, loss modulus, cross-link density, glass transition temperature, and activation energy for glass transition of the UV-PUA matrix are investigated. The effect of SiC content on the network structures and degree of curing of the nanocomposites was evaluated by William-Landel-Ferry (WLF) constants. The breadth of the glass transition in the tanδ curve and shape parameter (β) in the Kolrausch-Williams-Watts (KWW) equation were used to investigate the network heterogeneity of the samples. All these referred parameters increased with SiC nanoparticles loading up to 0.6% (wt). In contrast, upon introducing SiC at higher concentrations, the viscoelastic properties of the nanocomposites reduced significantly. SEM analysis was used to evaluate the DMTA results regarding the dispersion state of the nanoparticles in the matrix. Keywords UV-cured urethane acrylate · Nanocomposite · DMTA · Viscoelastic properties · Cross-link density
Introduction Polymeric products are usually comprised of two or more distinct materials with the ultimate performance that cannot be attained by any of the constitutive components alone. Improving mechanical properties is one of the purposes that reinforcing particles are introduced to polymer matrices. Effective mechanical reinforcement in polymer nanocomposites is governed by many factors such as aspect ratio, dispersion, and distribution state of the particles within the matrix and the strength of the interfacial area [1–3]. In nanocomposites, it is imperative that the applied external stresses are efficiently transferred to the nanoparticles and Electronic supplementary material The online version of this article (https://doi.org/10.1007/s13726-020-00871-z) contains supplementary material, which is available to authorized users. * Malihe Pishvaei [email protected] 1
Department of Resin and Additives, Institute for Color Science and Technology, P. O. Box 16765‑654, Tehran, Iran
the reinforcing particles take a disproportionate share of the load. Although one may expect that the mechanical properties of nanocomposites are dominated by exceptionally high strength and modu
Data Loading...
