Soy protein isolate instead of petrochemicals
In a recent study, researchers have achieved highly efficient self-initiated UV curing of waterborne coatings. Instead of petrochemicals, they used soy protein isolate as a co-initiator.
Using the emulsion polymerization method, the photoinitiator 4-hydroxybenzophenone (HBP) and the co-initiator soy protein isolate (SPI) were simultaneously grafted onto a polyacrylate molecular chain, and an innovative UV-curable polyacrylate resin based on the biomass macromolecular photoinitiator system SPI-HBP was created produced. It has been successfully developed into a type of waterborne coating with excellent mechanical properties for wood products.
Test results showed that the PA-SPI-HBP composite emulsion has good UV absorption performance. With an increase in HBP content, the UV curing time of the coating decreased from 10,68 s to 5,18 s. With an increase in HBP loading from 0% to 4%, the tensile strength of the films increased from 1,85 MPa 16,39 MPa, the tensile modulus of elasticity increased from 2,88 MPa to 374,81 MPa, and the elongation at break decreased from 559,03% to 38,46%. According to the researchers, their study offers a new method for the production of macromolecular photoinitiators from biomass and highly efficient self-initiating UV-curable wood coatings.
Source: Paint & Varnish and Progress in Organic Coatings, Volume 174, January 2023