摘要 |
A process for making a polysiloxane block copolymer which is built up from units of the formula [A] [B], in which A is a polymeric block built up from radically polymerisable monomer, and B is a polysiloxane block, the process comprising the steps of polymerising a radically polymerisable monomer in the presence of an atom transfer radical initiator to form an polymer which is end-functionalized with a leaving group capable of nucleophilic substitution by nucleophilic end-groups on a polysiloxane, and reacting the polymer with a polysiloxane having nucleophilic end-groups so that a polysiloxane block copolymer is formed via a nucleophilic displacement reaction between the end-groups on the polysiloxane and leaving groups on the polymer respectively. Also provided is a cosmetic and personal care composition, such as a hair styling composition, comprising the polysiloxane block copolymer as described above. |