TDI as main isocyanate, IPDI as end-capping reagent, waterborne polyurethane (WPU) surface-sizing agent have been obtained by a pre–polymerization process. WPU were mixed with starch SSA in different proportion and a composite sizing agent obtained. It is indicated the water resistance, gloss and folding resistance of WPU/starch sized papers are much higher than starch sized papers. The ink absorption obviously decreases and the mechanical properties wholly increase. WPU/starch composite emulsions is a new kind of surface sizing agent having broad development prospects.

TDI as main isocyanate, IPDI as end-capping reagent, waterborne polyurethane emulsions (WPUs) surface-sizing agent have been obtained. The properties of WPUs and papers sized by WPUs with different DMPA content, different NCO/OH molar ratio and nNCOTDI/nNCOIPDI are systematically examined. The results show that WPUs are new kinds of surface sizing agents with good properties. The water resistance, surface gloss and smoothness of papers sized by WPUs have dramatically increased. The folding endurance, tearing resistance and tensile strength of WPU sized papers are observed to increase obviously.

PB-1/PP blend was prepared by blending isotactic polybutene-1 and polypropylene with the ratio of 80/20 through Brabender extruder under melted condition, injected into the standard samples. After heat treatment at 75°C, the crystallization, crystal forms, dynamic mechanical properties, mechanical properties of the blends were studied via differential scanning calorimetry (DSC), X-ray Diffraction (XRD), dynamic mechanical analyzer (DMA) and mechanical testing machines, respectively. It was found that after heat treatment: both the melt temperature and the melting enthalpy of crystal form I in PB-1 component increased, the melt peak of crystal form II decreased gradually, while the melt temperature and melting enthalpy of PP as a disperse phase, maintained unchanged basically; the storage modulus of the blend increased and the tan δ decreased a bit; the mechanical properties of the blend were improved noticeable.