Esters are organic compounds that figure critically in the creation of polyesters. While the manufacture of esters and polyesters can be hard on the environment, new processes being developed by assistant professor of science Thomas DeRosa offer hope for a cleaner and more sustainable approach.
“What we’re doing is looking to make but polyester fibers using ‘green’ catalysts,” DeRosa says. Current manufacturing processes are anything but green, he adds, and typically rely on sulfuric or hydrochloric acid as the catalyst. “Once you use that kind of material, it has to be thrown out,” he says. “The catalysts we’re experimenting with are not only reusable, but if they dull with time, they can be easily reactivated, so nothing is wasted or thrown away. That’s what makes them ecologically superior.”
From three years to 20 minutes
In addition to lessening environmental impact, DeRosa’s process is potentially faster and more efficient, and that has important implications for industry. “When esters are made commercially, they’re typically heated to 130 degrees for at least three years,” he says. “We made one in the lab in less than 20 minutes.”
For DeRosa, the catalyst of choice is polyvinyl chloride, which is relatively easy to obtain and inexpensive. Whether it will enable the efficient production of polyesters remains to be seen. “If it works,” he says, “we’ll have the basis for applying for two U.S. patents.”
DeRosa, who arrived at BMCC this semester, has spent most of his professional career in industry—at Pfizer Pharmaceuticals, Allied Chemical Corporation and, most recently, Texaco, where he retired seven years ago as a senior scientific investigator. He has written 12 peer-reviewed scientific articles, holds 47 patents and has authored three books; a fourth will be published this summer.
Working with DeRosa as a research assistant is Samuel Adediji, a second-semester science major who plans to go on to Stony Brook University in the fall to study pharmacy. Born in Nigeria, Adediji moved to New York six years ago and learned about DeRosa’s work through the Louis Stokes Alliance for Minority Participation.
“Apart from the excitement of searching for ways to create new catalysts, it’s been very helpful and rewarding to learn how to maintain a scientific notebook and monitor experiments,” he says.
Keeping good notes
“Keeping an active notebook may sound unimportant, but it’s a key part of the scientific process,” says DeRosa. “Samuel is good at it—and an extremely bright and enthusiastic student who has been of enormous help.”
While DeRosa has high hopes for his “green catalyst,” he is realistic about its chances of acceptance. “There’s little likelihood that it will come into widespread industrial use immediately,” he says. “Companies have a lot of money tied up in existing processes and switching can be very expensive.” But if industries become convinced over time that his process is indeed more cost-effective, “it could become a very attractive alternative.”
