Vinylcyclopropane, monomer composition, polymer, polymer composition, and article

A vinylcyclopropane represented by general formula (I) shown below

• where, in general formula (I):
• R1 represents —H, —OH, —NH2, —NO2, —COOR, —CN, ═O, —OCOCH═CH2, —OCO(CH3)C═CH2, a halogen, an alkylene group having a carbon number of 1-20, a cycloalkylene group having a carbon number of 3-20, an arylene group having a carbon number of 6-14, or any one of an alkylene group having a carbon number of 1-20, a cycloalkylene group having a carbon number of 3-20, or an arylene group having a carbon number of 6-14 interrupted by O, S, N, or NH;
• X1 represents CO, CO—O, O—CO, CO—S, S—CO, CO—NR, NR—CO, O, S, SO2, or a single bond;
• X2 represents CO, CO—O, O—CO, CO—S, S—CO, CO—NR, NR—CO, O, S, SO2, or a single bond;
• for R1, X1, and X2, R represents H, an alkyl group having a carbon number of 1-6, a cycloalkylene group having a carbon number of 3-6, an aryl group having a carbon number of 6-14, or a heterocyclic group having a carbon number of 6-14;
• k represents an integer of 2-4;
• l represents an integer of 1-9;
• m represents an integer of 1-8;
• and
• Ad represents an adamantyl group.