سال انتشار: ۱۳۹۰

محل انتشار: کنفرانس بین المللی فرآورش پلیمرها

تعداد صفحات: ۴

نویسنده(ها):

Hesam Askari – Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O. Box 14965/115, Tehran, Iran.
Sayed Amin Mirmohammadii –
Mohammad Imani –
Moahammad Ataei –

چکیده:

Thermoset hybrid organic/inorganic nanocomposites were fabricated using multifunctional methacrylated polyhedral oligomeric silsesquioxane (POSS-MA) nanofiller dispersed in a matrice made of poly(-caprolactone diacrylate) (PCLA). To this end, PCLA was synthesized by acylation reaction of poly(-caprolactone diol) (PCLO) using acryloyl chloride. The macromer was thoroughly characterized. Nanocomposites were prepared via visible light-crosslinking of uniform mixtures of POSS-MA (0, 2, 5, 10, 20, 30, 40, 50 and 100%w/w) and PCLA using camphorquinone (QC) as a photo-initiator and 2-(dimethylamino)ethyl methacrylate (DMAEMA) as an accelerator (both of them 0.5%w/w relative to total PCLA and POSS-MA content in samples). Thermal stability of the initial macromer and final nanocomposite specimens was investigated by thermogravimetric analysis (TGA). Using POSS as reactive nanofiller and its consequent reaction with PCLA significantly increased thermal stability of the composite samples depending on POSS content. For example the initiation temperature of thermal degradation (Ti) and temperature of final degradation (Tf) increased from 395.57 to 409.77 and 448.19 to 473.80, respectively. This increase in thermal stability was attributed to formation of hybrid layer and the resulting physicochemical interactions between nanoparticles and polymer matrix. Thermal-mechanical properties of nanocomposites, including storage modulus, moduli at glassy and rubbery regions, Tg and tan  were evaluated by dynamic mechanical thermal analysis (DMTA) in compression mode for samples with 0 to 30% w/w POSS-MA. The difference between moduli at glassy and rubbery regions for nanocomposite with 30% w/w POSS-MA was 63.33 MPa. Brittle behavior was observed for nanocomposites at higher contents of POSS nanoparticles.