http://www.synbioproject.tech/cpi/applications/1-4-butanediol/
The major uses of bio-based 1,4-butanediol are in the production of THF and polybutylene terephthalate, or PBT. THF is used to produce spandex fibers and other performance polymers, resins, solvents and printing inks for plastics. PBT is an engineering-grade thermoplastic that combines excellent mechanical and electrical properties with robust chemical resistance. Source
In 2010, BioAmber licensed DuPont’s hydrogenation catalyst technology to make bio-based 1,4-butanediol, GBL and bio-based THF from its bio-based succinic acid. Source