Preparation and performance of the modified high-strength/high-modulus polyvinyl alcohol fiber/polyurethane grouting materials

In this study, modified polyvinyl alcohol fiber (MPVA) filled polyurethane (MPVA/PU) grouting materials with high interfacial bonding strength were prepared. Firstly, the high-strength/high-modulus PVA fibers were modified by γ-aminopropyl triethoxysilane (APTES) and diphenyl-methane-diisocyanate (MDI) respectively. The chemical structure, surface morphology and hydrophilicity were characterized by FT-IR, XPS, SEM and contact angle analysis. Second, the performance of PU mixed with different dosages of modified PVA fibers as the grouting material was studied. The results showed that mechanical properties and hot air aging resistance of the MPVA/PU composite were significantly increased compared with pure PU. In particular, it also can be found that modified PVA fiber bring better interface adhesion, especially, when the dosage is 0.1%, the best overall performance of MPVA/PU can be achieved. SEM analysis demonstrated that the interface adhesion between modified PVA fiber and PU was obviously improved.