Rigid Polyurethane Foam Particles Enhanced Recovery, And The Physical

In the past decades, in order to strengthen rigid polyurethane foam (PUF), various particles and fibers enhanced rigid polyurethane foam composites were synthesized and studied. Traditionally, organic modification is necessary to inorganic particles in order to improve compatibility between inorganic particles and polyurethane. In this paper, a kind of inorganic carbon sphere with a mount of hydroxyl groups on the surface, colloidal carbon sphere (CCSs), was synthesized and firstly incorporated into rigid polyurethane foam, with rigid polyurethane foam/colloidal carbon spheres (PUF/CCSs) composites prepared. Additionally, cell structures, mechanical and thermal properties of the composites were studied; what's more, strengthening mechanism was discussed.Wider applications and increasing consumption of rigid polyurethane foam result in more polyurethane waste and post-consumer polyurethane foam. Traditional disposal methods such as landfill and incineration have been restricted because of increasing landfill costs, decreasing landfill space and more and more attentions on environment issues. In this paper, polyurethane waste and post-consumer polyurethane foam were mechanically grounded into particles, and firstly incorporated into phenolic foam. Pulverized rigid polyurethane foam scraps (PPU) filled rigid polyurethane foam (PUF/PPU) and phenolic foam (PF/PPU) were prepared, and their cell structures, mechanical and thermal properties were studied. In addition, strengthening mechanism of both PUF/PPU and PF/PPU at the loading of 5wt% PPU was revealed firstly.The results show that the main component of CCSs prepared under hydrothermal conditions is disordered carbon with massive hydroxyl groups on the surface.The addition of CCSs results in sharp growth of the viscosity of polyol. Good compatibility between CCSs and PUF as well as good dispersion of CCSs in PUF are observed. Compared with neat PUF, CCSs/PUF composite exhibits finer cell structure, improved mechanical properties;exactly, the compressive strength and modulus increase by 35.5% and 15.2% respectively at the CCSs loading of 4.6wt%. The effects of CCSs on the thermal stability of the composites are slight.Post-consumer rigid polyurethane foam was grounded into particles with the size of 80-150μm. PPU swelled and well dispersed in polyol and phenolic resin; what's more, the addition of PPU induced a sharp increase of viscosities of both polyol and phenolic resin. In comparison with neat foam, both PUF/PPU and PF/PPU exhibit finer cell structure but more macro defects. What's more, improved mechanical properties are obtained for both PUF/PPU and PF/PPU at the PPU loading of 5wt%. Two degradation stages at 330℃-430℃and at 500℃-600℃were observed for PF/PPU composite, corresponding to the degradation of PPU and PF respectively, while for rigid PUF influence of PPU was very slight.