Hollow latex (HL) particles consisting of poly(methyl methacrylate-co-divinyl benzene-co-acrylic acid) were synthesised and used as an alternative white pigment in paint film.

 

The opacity of the coating film prepared from a mixture of HL or solid particles, poly(styrene-co-acrylic acid) and poly(styrene-co-methyl methacrylate-co-acrylic acid), was determined using the reflectometric method, which measures the hiding power of coatings.

 

Film containing HL showed better hiding efficiency

The film containing HL particles, allowing multiple light scattering, showed better hiding efficiency compared to coatings containing solid particles. The opacity of HL containing coating film linearly increased with the content of HL particles. For the adsorption of formaldehyde, the HL particles were further functionalised with amine containing compounds, i.e., chitosan and polyethyleneimine (PEI). HL-chitosan particles were well dispersed in coating film in contrast to the HL-PEI particles that were present as aggregates.

 

Therefore, HL-chitosan particles with highest coating opacity at 15 wt.% have the potential for utilisation as an opacifying agent or white pigment for special indoor coating applications.