Silicone polyoxamide copolymers with amine-based end groups

A method of making a copolymeric material comprising at least two repeat units of formula I′:

• wherein:
• each R1 is independently an alkyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo;
• each Y is independently an alkylene, aralkylene, or a combination thereof;
• each G is a bond or alkyl (CH2)n, alkyl-aryl (CH2-Ar—CH2), aryl, heteroaryl, heterocycle, or carbocycle;
• each R3 is independently hydrogen or alkyl;
• each n is independently an integer of 0 to 300;
• each p is independently an integer of 1 to 25;
• and
• each q is independently an integer of 1 to 2, and the average of q is no greater than 1.05
• the method comprising:
• (a) adding an oxalate ester of formula II to a solvent
• wherein:
• each R2 is independently an alkyl, haloalkyl, aryl, or aryl substituted with an alkyl, alkoxy, halo, alkyoxycarbonyl, or
• bound through the N, wherein each R4 is independently hydrogen, alkyl, or aryl or R4 taken together form a ring;
• (b) reacting the oxalate ester with a polydiorganosiloxane diamine of formula III until essentially no polydiorganosiloxane diamine or oxalate ester remains
• to form the reaction product of formula IV
• (c) adding one or more diamines of formula V to the reaction product of formula IV to form the repeat unit of formula I′
• and
• (d) adding one or more amine-based capping agents of formula VI to halt polymerization and modify end groups of formula I′
• wherein R4 is hydrogen or methyl, haloalkyl, aralkyl, alkenyl, aryl, or aryl substituted with an alkyl, alkoxy, or halo;
• and R5 is hydrogen (as part of alkyl chain or aryl group), aryl, heteroaryl, amide, carbamate, or urea.