Reprocessing And Performance Of Composite Panels Of SAN Foam With Thermoplastic Polyurethane

In this thesis, hot-pressing moulding was used for recycling waste thermosettingplastic styrene acrylonitrile copolymer (SAN) power. Composite regenerated panelsof waste thermosetting SAN with thermoplastic polyurethane (TPU) which hadsandwich structure were prepared. The processing conditions of regenerated panelswere optimized. And one kind of TPU film was selected according to the propertiesand cost. Moreover, TGA, DSC, XRD, FTIR, SEM and AFM were conducted toinvestigate the relationship between the performance and the structure of the panels.Results showed that the best processing condition of hot-pressing moulding wasthat the density was1.3-1.5g/cm~3. The upper die temperature was187℃, and thebottom die temperature was185℃. Hot-pressing pressure was18MPa, andprocessing time was15min. For composite regenerated panels,0.2mm of TPU filmwas chosen. The upper die temperature was172℃, and the bottom die temperaturewas170℃. Hot-pressing pressure was18MPa, and processing time was15min. Theabsorbing water rate of the products was all under1%. The absorbent thicknessexpansion rate was under0.5%. Resistance to solvent and fire resistance of the panelsboth met national standards.TGA showed the decomposition temperature of SAN regenerated panels wasincreased, while the decomposition temperature of composite regenerated panels wasreduced due to TPU. The DSC curves of the panels appeared split bimodality becauseof the formation of crystal or crosslinking structure. And XRD accounted for theincrease of crystallinity of panels by hot-pressing. FTIR proved that a newcrosslinking structure might be formed in intermolecular. Furthermore, SEM showedthe morphology of high density of regenerated panels was uniform, and TPU could bewell combined with the matrix. AFM displayed that the higher density was, the moreuniform morphology and phase of the panels were.