Renowned chemist speaks at Viterbi lecture Thursday


The Mork Chemical Engineering Department hosted a distinguished lecture by Megan L. Robertson from the University of Houston on biorenewable polymers for energy and the environment on Thursday afternoon at Zumberge Hall.

Robertson discussed her research on polymers synthesized from sustainable sources. These polymers are more environmentally friendly than polymers synthesized from fossil fuels.

“Our goal is to make polymers with reduced impact derived from sustainable resources,” Robertson said. “We want to find an alternative to using petroleum.”

Professor Malancha Gupta invited Robertson to speak at USC after meeting her at a chemical engineering conference.

The talk started with Robertson’s description of life cycle analysis, which examines key factors that have environmental and sustainable impact. These factors include energy, water, chemicals, raw materials, end-of-life fate and byproducts. She said chemical companies are working to make their practices more sustainable.

“There has been a large resurgence in sustainability,” Robertson said. “Oil will be around for a long time, but it will become harder to get. There are environmental consequences to obtaining oil in new ways.”

In Robertson’s research, she chose to synthesize these polymers with vegetable oils. The goal is to get these sustainable polymers to act similarly to typical elastomers — plastics that display elasticity.

Elastomers are created in a general sense by melting a polymer so that it can take on any shape. Once the polymers are cooled down, they harden by locking in their structure.

The vegetable oil-based polymer would have to be created through triblock copolymers, polymers with different properties that automatically segregate and create a structural framework. Fatty acid acrylates are the basis for this design.

Robertson explained that there are additional materials other than vegetable oils that can be used, including biomass, vegetable products, plants, polysaccharides and terpenes (a natural form of rubber). For example, cellulose has also been used as an additive to plastic in Dasani water bottles.

Throughout the rest of the presentation, Robertson explained in detail how she compared the properties of plant-based polymers to the properties of petroleum-based polymers. These tests compared structure, mechanical properties and tensile strength.

One of these tests looked at the structure of the newly created polymers by shearing the polymers.

These tests yielded results that showed that work still needs to be done to create applicable plant-based polymers.

“Part of the issue stems from the fact that the molecular weight of the polymer has to reach at least 170 kg per mole to see actual mechanical properties,” Robertson said.

The rest of the event was yielded to questions, during which time audience members asked about the specifics of handling these polymers and how the topics discussed could be applied to their own research projects.

Students studying all facets of chemical engineering and material sciences sat in on the lecture.

Robert Frank-Finney, a Ph.D. student working with Gupta on making polymers from the vapor phase, said he sees the real-world benefits of using plant-based polymers.

“We want to be able to do the same things that petroleum can do and possibly new things,” Frank-Finney said.