| abstract |
Oxygen-permeable moulding comprises a block copolymer of formula A-B, A-B-A, or B-A-B contg. 30-70 wt.% of segment B. Segments A and B show small microdomains in wavelengths of visible light. Also if VA and Pa stand resp. for vol. ratio and oxygen permeability coefft. of segment A and VB and PB the corresponding values for segment B, oxygen permeability of the moulding is 0.5-1 times VAPA+VBPB. Segment A comprises at least 80wt.% of alkyl methacrylate units with 1-4C alkyl, and B comprises at least 80wt.% units pref. from a monomer of formula CH2=C(CH3) COOCmH2mSiX3, M=2-5 X=indep. methyl or a gp. of formula (I9 n=0-30. |