A polycaprolactone-based compatibilization treatment to improve dispersion and interphase structure of silica polyurethane composites

LEONEL CHIACCHIARELLI; LEANDRO MONSALVE; ANALIA VAZQUEZ; JOSE KENNY; LUIGI TORRRES

POLYMER ENGINEERING AND SCIENCE

SPE

Año: 2014 vol. 54 p. 1817 - 1826

1548-2634

Silica nanoparticles (SN) were grafted with e-caprolactone using an environmentally friendly approach. By using tartaric acid as a catalyst and the silanol groups as initiators, grafted nanoparticles (GN) with organic weight fractions (wof) in the range 0-46 wt.% were synthesized. Thermogravimetric weight loss (TGA) and infrared analysis were used to measure the wof and to corroborate the covalent bond between the silica nanoparticle and the caprolactone monomer. The GNs were used to prepare polyurethane (PU) nanocomposites. Transmission Electron Micrographs (TEM) corroborated that the GNs interfacial area with the PU increased by the reduction of agglomerate dimensions from 10mm to around 100nm. Dynamic Mechanical Analysis, Differential Scanning Calorimetry (DSC), X-Ray Diffraction, TGA and Tensile tests were used to evaluate the effect of changing wof and filler concentration on the nanocomposite properties. At low wof (<15%), the GNs improved Elastic Modulus (), Strength () and Ductility (). At higher wof (<15%), the properties of the nanocomposite tended to change. The thermal stability of the GN based PU nanocomposites was improved, mainly by increasing the stability of the castor oil based soft segments