Date of Last Revision

2023-05-03 12:50:05


Chemical Engineering - Cooperative Education

Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2019


The most common method of polyurethanes involves a reaction between various petroleum-based isocyanates and a polyol along with a catalyst; all of which have a negative impact on environmental and human health. The objective of this research project is to eliminate or mitigate the risks and hazards associated with the production and degradation of polyurethane. Hexamethylene diisocyanate isocyanurates (3HDI) are one of the most common isocyanates used in the polyurethane processing industry. 3HDI contains numerous toxins, and it has a negative impact on the environment and human health1. It has been found that there are other compounds that can be used as alternatives to 3HDI. One of these alternatives is a bio-based compound known as 2-heptyl-3,4-bis(9-isocyanatononyl)-1-pentylcyclohexane, or DDI. In this project 3HDI, DDI, and linseed oil were tested as coatings on samples of sheet metal to determine their effectiveness as a coating. Linseed oil was used as an organic and unprocessed control. The coatings of each substance were tested in numerous ways including mechanical methods and chemical methods. Mechanical testing including pendulum hardness, cross-hatch adhesion, pencil hardness, and thickness. Chemical testing included chemical resistance, and electrostatic impedance spectroscopy (EIS). The results for each test were analyzed and compared amongst all three coatings. The linseed oil coating performed the worst with significantly lower protection of the metal substrate compared to DDI and 3HDI. DDI performed significantly better than the control coating, but it did not compare to 3HDI. 3HDI had much superior mechanical and chemical integrity results than DDI. The only test that DDI had similar outcomes with 3HDI was the pendulum test. This study shows that replacing 3HDI with DDI would most likely not be successful due to DDI being significantly inferior to 3HDI in mechanical and chemical aspects. DDI would be a viable option if the use of the polyurethane would not be affected by a significant decrease in integrity.

Research Sponsor

Dr. Qixin Zhou

First Reader

Dr. Hongbo Cong

Second Reader

Dr. Roya Gitiafroz



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