Polymer and composition including same, and adhesive composition

A polymer having a weight-average molecular weight of 1,000 to 100,000, comprising a structural unit of Formula (1):

• {where Q is a bivalent group of Formula (2) or Formula (3):
• (where Q1 is a C1-6 alkyl group, an allyl group, a vinyl group, an epoxy group, or a glycidyl group, each of Q2 and Q3 is independently a hydrogen atom, a C1-6 alkyl group, an allyl group, a vinyl group, an epoxy group, or a glycidyl group, and n is 0 or 1);
• when Q is a bivalent group of Formula (2) or Formula (3), and n is 1, a carbonyl group composing a portion of each of Formula (2) and Formula (3) is bonded to a nitrogen atom of Formula (1);
• R1 is a C4-8 alkylene group, or a group of Formula (4) or Formula (5):
• -A1-R2-A2- (4)
• —R3-A3-R4— (5)
• (where each of A1, A2, and A3 is independently a C6-14 arylene group or a C4-10 cyclic alkylene group, R2 is a sulfonyl group, a carbonyl group, or a C1-5 alkylene group, at least one hydrogen atom of the alkylene group is optionally substituted with a halogen atom, and each of R3 and R4 is independently a C1-5 alkylene group)}.