oup consisting of C1-C6-alkyl; cyclohexyl, phenyl and ???(CHR???CHR???O???)pR12, wherein p is an integer less than about 50; R12 is selected from the group consisting of hydrogen and C1-C6 alkyl; L2 is selected from the group consisting of C2-C6-alkylene, ???(CH2CH2O)p???CH2CH2??? and ???CH2-cyclohexane-1,4-diyl-CH2???, wherein p is an integer less than about 50; and L3 is selected from the group