Stability and Mechanical Properties of Hard/Soft Latex Blends

Abstract

In this contribution, hard/soft latex blends were prepared by mixing proportionable non-crosslinkable hard and self-crosslinkable soft latices. The stability and mechanical properties of latex blends were comparatively studied with the neat latex with high glass transition temperature (Tg). It was found that the calcium ion stability of the latex blends is better than neat hard latex. In addition, the stress at break decreased with the increasing of φs (mass fraction of soft particle in latex blends) and the break elongation increased when φs below 0.8. Meanwhile, the value of tensile stress and break elongation of the hard latex film with coalescing agent, DPnB, additive is between that of the latex blends film with 60% and 70% soft particle. The study on viscoelasticity of the latex films demonstrated that this composite latex can be considered as phase separation blend involving a soft phase filled with hard spheres. The results indicate that the soft latex can serve as the substitution of coalescing agents in water-based ink industry to obtain low or zero VOC ink, without compromise on properties.