Investigation of the preparation and superior properties of novel propylene-based elastic HMAs

Novel propylene-based elastic hot melt adhesives (HMAs) with improved adhesive and elasticity were prepared by the styrene-assisted melt free-radical grafting of maleic anhydride method. The changes in chemical composition, thermal property, melt viscosity, and adhesive performance were measured by Fourier transform infrared spectroscopy (FTIR), Gel Permeation Chromatography (GPC), Temperature Rising Elution Fractionation (TREF), rheology, Differential Scanning Calorimetry (DSC), Transmission Electron Microscopy (TEM), Thermo Gravimetric Analyzer (TGA), melt flow indexer, and Instron universal testing machine. Compared to the commercial propylene-based HMA products, the prepared propylene-based elastic HMAs exhibited better thermal stability and a lower degree of crystallinity, and a special continuous phase distribution. In addition, a 20% increase in peel strength, and doubled 100% tensile deformation recovery rate were also observed, which showed a consistent of high degree of adhesion and elasticity had been achieved. Meanwhile, the weather resistance test results also indicated that the propylene-based elastic HMAs had excellent ability of weather resistance with high and low temperature shock, which alleviated the interface delamination caused by the different thermal shrinkage between the steel interface and plastic interface, further benefiting and extending the service life of steel composite pipes. The propylene-based elastic HMAs with higher adhesive and elasticity had excellent ability of weather resistance, which alleviated the interface delamination caused by the different thermal shrinkage between the steel and plastic interface.