The present invention relates to a method for making a polymer wherein during ring opening polymerisation is incorporated into the polymer chain at least one cyclic (alkyl) carbonate monomer having the formula (1) wherein Y is optional and represents the residue of a sulfhydryl reacted group, X represents a functional group reactive with a sulfhydryl group, L=—[CH2]n with n=0-10, or L=−[CH2]p-S—S—[CH2]q with p and q are 0-5 or L=-[PEG]- with PEG is a group that comprises a —[CH2CH2O]m-group with m=1-200, and R2 is hydrogen, methyl or ethyl. Optionally a cyclic (alkyl) acryloyl carbonate, or other additional monomer A may be used as comonomer. The polymer may be formed into a polymer article, such as a polymer film, such as a coating and modified and/or cross linked, to a polymer or polymer article obtainable, and to a biodevice, their use, and to the cyclic (alkyl)carbonates.
