4. The cross-linking reaction of polyvinyl alcohol forms four water molecules for every B(OH)4 that cross-
links two polymer chains. Given the sections of polyvinyl alcohol chains below, sketch how B(OH)4
cross-links the chains. Through what atom chain linkages are the C-C polymer backbones connected?
CH
CH₂
H
O-H
O-H
H
H
CH₂
H-O.
+B (OH)4
H
H
CH₂
