Green Chemistry of Poly(l-lactides)
As part of a series of studies on the green chemistry of poly(l-lactides), we have performed a theoretical study of the mechanism of ring-opening polymerization. We have investigated two alternative mechanisms for the ring-opening polymerization of l-lactide using a guanidine-based catalyst, the first involving acetyl transfer to the catalyst, and the second involving only hydrogen bonding to the catalyst. Using computational chemistry methods, we show that the hydrogen bonding pathway shown above is preferred over the acetyl transfer pathway and that this is consistent with experimental information.
Closing the Loop on Recycling: Can We Stop the oil-to-Landfill Treadmill?
Poly(ethylene terephthalate) (PET), a widely used engineering thermoplastic for carpet, clothing (fibers), tire cords, soda bottles and other containers, film, automotive, electronics, displays etc., will contribute several billion pounds of waste to landfills this year alone! According to the American Plastics Council, PET packaging was originally used for soft drinks, but packing applications today include other beverages such as water, juice, beer, in addition to other foods such as peanut butter and ketchup and a variety of other household products.
Simulations of Polyphenylacetylene (PPA) “Foldamers”
Vijay Pande, Stanford University.
What are PPA “foldamers”
nonbiological polymers that fold
model systems for self-assembling nano structures
challenge for simulation: long timescale and complex dynamics
longer chains considerably are more complex: multiple traps and remarkable complexity
new methods used to predicted long timescale behavior: Markovian model and Folding@Home grid computing
Folding@Home: a new paradigm […]