| abstract |
The present invention relates to thermally expandable microspheres at least partially prepared from biologically-derived monomers and a process for making them. The microspheres comprise a thermoplastic polymer envelope encapsulating a blowing agent, the thermoplastic polymer shell comprising a polymer which is a homopolymer or a copolymer of a lactone according to formula (1): in which each of R 1 , R 2 , R 3 , R 4 , independently of one another, is selected from the group consisting of H and an alkyl group preferably with 1 to 4 carbon atoms. The invention further relates to expanded microspheres, which can be used in a variety of applications. |