Thermal stability and viscoelastic properties of MF/PVAc hybrid resins on the adhesion for engineered flooring in under heating system; ONDOL

The thermal properties of blends of melamine-formaldehyde (MF) resin and poly(vinyl acetate) (PVAc) for engineered flooring used on the Korean traditional ONDOL house floor heating system were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The viscoelastic properties of the blends were also studied. Because MF resin is a thermosetting adhesive, the effect of MF rein was shown across all thermal behaviors. The addition of PVAc reduced the curing temperature. The TGA results showed that the DTGmax temperature and thermal stability of the blends increased with increasing PVAc content. The blends were examined in non-isothermal DSC experiments at a heating rate of 10 °C/min. There was an exothermic peak in all the heating scanning curves, with each blend displaying a single curing peak temperature (Tp), intermediate between those of the two pure components and varying with the blend composition. The DMTA thermogram of MF resin showed that the storage modulus (E′) increased as the temperature was further increased as a result of the cross-linking induced by the curing reaction of the resin. E′ of MF resin increased both as a function of increasing temperature and with increasing heating rate.