The patent was from an application that I had filed back in 2012 when I was at Aspen Research. It involves the use of chicken feathers as a base for polymerizations. Chicken feathers are mostly a waste product that is largely ends up being buried. In the US alone, 4 - 5 billion pounds end up underground and so it represents a huge potential feedstock that is biobased and present around the world. That's at least 4 - 5 billion pounds of plastic that could be made, and more if the feathers are combined with other materials. We used to dream big and joke that the first 5 billions pounds would be free. After that:
|"Eat more cowz!"
The Public PAIR website also showed that there was no office action - the patent sailed through unchallenged by the examiner. That's a first for me.
Coincidentally, I was just thinking about that chemistry yesterday before getting the letter. It's been a couple of years since I've worked with the stinky mercaptans, but it all came back when I read the latest installment of the Master Organic Chemistry blog on thiol reactions. James points out that mercaptans are analogous to alcohols in some ways (as would be expected), but not in others, particularly when undergoing oxidations. Alcohols are progressively oxidized to ketones/aldehydes and then carboxylic acids, while thiols are only oxidized to disulfides. I had never really given it much thought. Why aren't there -CSSH groups for instance? Apparently a C=S bond is rather unstable.
Update: As Joe Q. pointed out in the comments, dithiolcarboxylic acids (-CSSH) do in fact exist. A closer rereading of the James's post made it clear that thioketones and thiolaldehydes are what he was discussing, although they can be stabilized with an adjacent nitrogen or other functional groups, which was also mentioned by Joe Q.
[*] The file wrapper is an ancient term for all the paperwork associated with an patent application.