Improving Moisture Retention in Flour-Based Materials Using Propylene Glycol

Water retention is one of important characteristics of paint. To make a natural paint, people use flour as base; however, flour tends to crack easily due to water loss. For this reason, we decided to add propylene glycol which is water absorbent that can prevent water loss. To test our hypothesis, we used 0.1% to 20% propylene glycol (w/w%) and observed over a 5 day period. After successful trials, we found that higher propylene glycol concentrations led to lower mass loss. On day 5, the 0.1% propylene glycol concentration demonstrated the highest mass loss, while the 20% propylene glycol demonstrated the lowest mass loss at 6.98%. The effect of propylene glycol on relative moisture content was also observed over the same 5 day period. Overall, higher propylene glycol concentration resulted in a lower change of moisture content from day 1 to day 5. On day 5, 0.1% propylene glycol concentration demonstrated the highest negative change in moisture content, while 20% demonstrated the lowest negative change in moisture content with a change of only 16.4%. These results suggest that higher concentrations of propylene glycol may overall improve water retention and mass preservation potentially due to the interactions between propylene glycol and water.