Preparation And Characterizatiovn Of Polyurethane UV-curable Coatings Embedded With Imidazolium/QPS Antibacterial Unit

Environmentally friendly functional coatings with efficient antibacterial activity have an important application value.At present,some coatings are still facing several problems:Firstly,volatile solvents would release during the formation of the coatings,which can easily lead to environmental pollution.Secondly,a large percentage of coatings are lack of antibacterial properties,or have a poor antibacterial property due to the bacteria resistance.In order to solve these problems,here,three series of polyurethane UV-curable antibacterial coatings were prepared by introducing cross-linked antibacterial ingredients into the UV-curable coating.The corresponding antibacterial activity against E coli and S aureus was also explored.The main results are as follows.(1)Preparation of serial UV-curable antibacterial polyurethane coating carrying imidazolium groups.1-Allyl-3-alkylimidazolium bromide(ATM)was synthesized by allyl imidazole with antibacterial structure and alkylbromide,and then the corresponding UV-curable antibacterial polyurethane coatings were prepared through the formation of chemical bonds between AIM and PUA under the UV-curable technology.The corresponding structural and performance characterization were also carried out.When the weight percentage of AIMC14 was 5%,the prepared PAIMC14-5wt%film have a high embedded rate of 95%.This film also has good heat-resistance,low water uptake of 2.5%and pencil hardness of HB.Besides,the antibacterial rate of PAIMC14-5wt%film against E coli and S aureus can reach 99.0%within 3h.(2)Preparation of serial UV-curable antibacterial polyurethane coating embedded with monomeric quaternary phosphonium salt(mono QPS),gemini QPS and tetra-QPS.Firstly,mono QPS(4-(2,3-dihydroxypropoxy)phenyl)triphenylphosphonium bromide(MQPS)was synthesized by using triphenylphosphine,acetone glycerin and p-bromophenol as raw materials through four steps reaction.Secondly,starting from 1,6-bis(diphenylphosphino)hexane,three kinds of gemini QPS with dihydroxy were synthesized,namely hexane-1,6-diylbis((4-hydroxyphenyl)diphenylphosphonium)bromide(GQPS1),hexane-1,6-diylbis((4-((6-hydroxyhexyl)oxy)phenyl)-diphenyl-phosphonium)bromide(GQPS2),hexane-1,6-diylbis((4-((10-hydroxydecyl)oxy)phenyl)diphenylphosphonium)bromide(GQPS3).Thirdly,GQPS4 was synthesized by using GQPS1 and 1,6-dibromohexane as raw materials.Subsequently,the five kinds of QPS were embedded into PUA backbone by reacting with isophorone diisocyanate,and the corresponding films were prepared under UV irradiation.Then the corresponding structural and performance characterization were also carried out,respectively.The prepared PGQPS4-1wt%film have a high embedded rate of 92%,low water uptake of 3.2%and pencil hardness of 3H.(3)The test of antibacterial properties of all polyurethane UV-curable coatings embedding QPS.After bearing different cationic units mono QPS,gemini QPS and tetra-QPS,respectively,the antibacterial properties of corresponding UV-curable coatings increased under the same conditions.Especially for PGQPS4-1 wt%film,the antibacterial rate reached 99.9%in 3h at a low weight percentage of 1%.It indicates that the antibacterial effect can enhance with the increase of cationic charge density,which provided a new clue for further design of new antibacterial unit.