I am working with triazine based hyperbranched polyamine which does not show any antimicrobial activity. But all the triazine based polymers showed antimicrobial activity in the reported literature.
in case of Triazine, the nitrogen atoms are capable to form hydrogen bondings. this leads to formation of charges on triazine (also known as biocides). the positive charge created on nitrogen attracts negative charge on bacteria and kills them (biocidal activity).
Why should triazine be anti microbial? In our experience we even think triazine based structures enhance microbial growth as it provides a source of nitrogen on seemingly inhospitable surfaces, such as painted things (using resins cross-linked with HMMM).