A New Approach to Making Bio-Synthetic Latexes

Collaborator: Dr. Marc A. Dubé, University of Ottawa

Industry Partner: EcoSynthetix Corp.

Starch nanoparticles (SNP) produced from gelatinized starch are receiving increasing attention in both academia and industry. SNP are attractive materials because of their relatively low cost, biocompatibility and biodegradability. Starch solutions typically give very high viscosity, thereby limiting the solids content of starch solutions, while SNP dispersions can have much lower viscosity, facilitating their use at significantly higher loadings. Incorporating of SNP into petroleum-derived synthetic polymers could not offer unique and valuable performance enhancing properties for the hybrid material, but would also give a more sustainable product because of the renewable content.

However because starch is quite hydrophilic, SNP are not compatible with most synthetic polymers (which are usually hydrophobic) and are therefore difficult or impossible to incorporate or blend with other polymers.  A solution to this problem is to graft (chemically attach) a small amount of synthetic polymer to the SNP to make them compatible with synthetic polymers. We are using a type of controlled radical polymerization (nitroxide-mediated polymerization, NMP) to graft various synthetic polymers onto the surface of SNP to yield a core-shell particle structure consisting of a starch core, and a shell of any polymer deemed suitable for a particular application.

Schematic representation of the grafting from reactions, illustrating the grafting of synthetic polymers to starch nanoparticles (SNP) using nitroxide-mediated polymerization.