Preparation and Properties of 4-Vinylpyridine Zwitterionic Copolymer Resin

Zwitterionic polymers have been extensively studied in recent years due to their excellent antifouling properties. By radical copolymer with 4-vinylpyridine (4-VP), ethyl acrylate (EA) and butyl acrylate (BA), the zwitterionic copolymers (P(4-VP-co-EA-co-BA)) with different copolymerization ratios were prepared. Then, P(4-VP-co-EA-co-BA) was modified by 1, 3-propanesultone (1, 3-PS) to obtain functional zwitterionic copolymer resin P(4-VPPS-co-EA-co-BA), which had excellent antibacterial and antifouling property. In order to improve the stability in the water and the mechanical properties, P(4-VPPS-co-EA-co-BA) was cross-linked by different amounts of dichloroethane. Finally, P(4-VP-co-EA-co-BA) and P(4-VPPS-co-EA-co-BA) were characterized by H-nuclear magnetic resonance (¹H-NMR) and Fourier transform infrared spectroscopy (FT-IR). Thermal properties, mechanical properties, antibacterial properties and antifouling properties of P(4-VPPS-co-EA-co-BA) were examined by thermal-gravimetric analysis (TG), universal material testing machine, the serial dilution and spread plate technique and microscope, respectively. Results indicated that P(4-VP-co-EA-co-BA) and P(4-VPPS-co-EA-co-BA) were successfully prepared. When the mole fraction of 4-VPPS unit in P(4-VPPS-co-EA-co-BA) (f_4-VPPS) was changed from 14.4% to 28.9%, the tensile strength was improved from 6.51 MPa to 8.93 MPa, while the elongation at break was reduced from 219.00% to 147.60%. When f_4-VPPS was 24.2%, the mechanical properties of P(4-VPPS-co-EA-co-BA) became balanced with tensile strength and elongation at break reaching 7.02 MPa and 195.26%, respectively, meanwhile the thermal decomposition temperature was 299℃. What's more, the tensile strength of P(4-VPPS-co-EA-co-BA) was greatly improved by cross-linking reaction with dichloroethane. When cross-linking degree was 6%, tensile strength and elongation at break reached 9.97 MPa and 152.21%, respectively. And the water absorption of P(4-VPPS-co-EA-co-BA) was reduced by cross-linking reaction with dichloroethane. When f_4-VPPS reached 19.2%, antibacterial and antifouling abilities of P(4-VPPS-co-EA-co-BA) were excellent to Escherichia coli and Staphylococcus aureus.