Previous work in this field of research has proven that the intrinsic properties of native starch can be modified to have desirable traits. For example there are two widely researched natural properties of native starch: physically brittle and hydrophilic. Researchers have been successful at mixing native starch with various polyols or water to yield a modified starch with viscoelastic behavior. Furthermore low miscibility of native starch with other polymers has made it the topic of polymer blend studies to help alleviate its hydrophilic nature.

For this study materials were selected based on both previous research and ability to create test samples from corn starch that behave in a viscoelastic and hydrophobic manner. Castor oil is chosen as the polyol because it is naturally abundant, hydrophobic and proven to be reactive with isocyanate. 4,4, methylene diphenyl diisoycanate is chosen on the basis of reactivity with castor oil and corn starch.

The aim of this study is develop and characterize foam materials derived from corn starch and a pre-polymer made from castor oil and 4,4, methylene diphenyl diisocyanate. Castor oil and 4,4, methylene diphenyl diisocyanate polymerize to yield random urethane crosslink’s. When gelatinized starch and the pre-polymer are mixed, secondary interactions between these 2 components are evident. The effect of chemical and physical foaming agents is analyzed, where chemical foaming agents behave both exothermic and endothermic, the physical foaming agent behaved endothermic. In addition the change in starch proportion is also investigated. Results show different mechanical behavior from what is found in literature and can be attributed to direct fraction of gelatinized starch and both type and dispersion of foaming agent.

Library of Congress Subject Headings

Foamed materials--Mechanical properties; Polyurethanes--Mechanical properties; Starch--Mechanical properties

Publication Date


Document Type


Student Type


Degree Name

Packaging Science(MS)

Department, Program, or Center

Packaging Science (CAST)


Changfeng Ge

Advisor/Committee Member

Deanna Jacobs

Advisor/Committee Member

Christopher Lewis


Physical copy available from RIT's Wallace Library at TP1180.P8 L36 2016


RIT – Main Campus

Plan Codes