Thermomechanical behavior and thermal stability of polyurethane rigid nanocomposite foams containing binary nanoparticle mixtures

BURGAZ E., Kendirlioglu C.

POLYMER TESTING, vol.77, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 77
  • Publication Date: 2019
  • Doi Number: 10.1016/j.polymertesting.2019.105930
  • Journal Name: POLYMER TESTING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: Thermal stability, Thermomechanical behavior, Morphology, Nanocomposite, Polyurethane, Nanoparticle, Rigid foam, MULTIWALL CARBON NANOTUBES, OF-THE-ART, MECHANICAL-PROPERTIES, INSULATION MATERIALS, PHYSICAL-PROPERTIES, FLAME-RETARDANT, MORPHOLOGY, SILICA, POLYMERIZATION, COMPOSITES
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

Polyurethane (PU) rigid nanocomposite foams containing binary nanoparticle mixtures were prepared via reactive foaming process by using the synergy of mixing based on H-bonding interactions between nanofillers and polymer matrix. Using a very high surface area hydrophilic fumed nanosilica with a primary particle size of 7 nm and a concentration of less than 0.2 wt% in addition to carboxylic acid functionalized multiwalled carbon nanotubes (MWCNTs-COOH) in PU rigid foams leads to improved thermal stability, thermomechanical and mechanical properties. Particularly, the system containing both 0.4 wt % CNT and 0.1 wt% nanosilica has a much higher value in terms of T-g, storage modulus value at T-g, reduced compressive strength, thermal stability and cell density compared to the sample containing only 0.5 wt% CNT. Based on FT-IR results, favorable and enhanced H-bonding interactions of N-H and carbonyl functional groups of the urethane linkage in PU chains with surface silanols of hydrophilic nanosilica particles and carboxylic acid functional groups of MWCNT-COOH were shown to be the main reasons for the reinforcement effect in PU rigid foams.