Mechanism Confirmation of Organofunctional Silanes Modified Water Glass/Polyurethane-Urea Composites for Remarkably Enhanced Mechanical Properties

Abstract

Hybrid reinforced water glass/polyurethane-urea (WG/PU) composites mainly derived from low-cost WG and polyisocyanate are produced in the presence of 3-chloropropyltrimethoxysilane (CTS). The wettability of WG on PU substrate surface is significantly improved as CTS content increases from 0.0 wt% to 3.5 wt%. Furthermore, with 2.5 wt% of CTS optimal addition, the fracture surface morphology and elemental composition of the resulting WG/PU composites are characterized, as well as mechanical properties, chemical structure and thermal properties. The results indicate that the CTS forms multiple physical and chemical interactions with the WG/PU composites to induce an optimized organic-inorganic hybrid network structure thus achieving simultaneous improvement of compressive strength, flexural strength, flexural modulus and fracture toughness of the WG/PU composites, with the improvement of 12.9%, 6.6%, 17.5% and 9.7%, respectively. Moreover, the CTS in the WG/PU composites has a significant influence on the curing process of the WG/PU composites by accelerating the rate of mass and heat transfer. Additionally, a reasonable mechanism explanation for CTS modified WG/PU composites is confirmed.