Synthesis And Applications Of Visible-Light-Degradable Picolinium-Contained Polymers

Polymeric materials have been extensively used in our daily life,but numerous of non-degradable waste has brought serious pollution.Therefore,designing photo-or bio-degradable polymers is considered as apromising strategy to resolve this problem.As for photodegradable polymers,the degrading process mainly depends on the photocleavage of special groups in polymer chains.Compared with high energy-contained triggers,e.g.,UV light and?ray,visible light is more harmless to biological samples and shows better tissue penetration ability.N-Alkyl Picolinium Esters?NPEs?are a kind of visible-light-labile group,and the C-O bond can be efficiently cleaved via a photoinduced electron transfer process with the catalysis of the ruthenium complex and ascorbic acid?Ru?II?/ASC?upon visible light irradiation.With these advantages,two novel visible-light-degradable polymers were for the first time designed:?1?Synthesis of a visible-light-degradable polymer with NPEs located in main-chain and its applications A main chain visible light labile linear polymer?MCPP?is synthesized via condensation polymerization.And it has a high photodegradable efficiency?95%?upon visible light irradiation,which can be tuned by adjusting the concentration of Ru?II?or ASC,irradiation intensity and time.Furthermore,the results of MALDI-TOF indicate that the molecular weight has significant changes after photodegradation and decrease to⁶50 g mol^-1.Unlike forming a helix structure of pure polyethylene glycol,MCPP is in a linear conformation in water because of the introduction of rigid NPEs group.Moreover,nanopore-based single-molecule analysis shows that both the MCPP and degraded products can easily pass through a biomimetic lipid membrane with a tunable passing speed by varying the applied bias voltage.Cell cytotoxicity and proliferation experiments demonstrate that both the MCPP and degraded products have low toxicity.Moreover,the MCPP can enhance cell proliferation effectively.These results indicate the MCPP can be used in the fields of materials,chemistry and biology.?2?Synthesis of a visible-light-degradable polymer ionic liquid with NPEs located in side chain and its applications A novel visible-light-labile polymer ionic liquid?VP-PIL?is synthesized via the method of classic free radical polymerization that contains NPEs in side chain.The result of TG and DSC indicate that the as-prepared VP-PIL features low glass transition temperature?Tg=47??and high thermal stability?Td=284??.The structure and visible light degradable property have been characterized by NMR and FT-IR.The VP-PIL,a visible light degradable polycation,is used to fabricate visible light degradable lay-by-lay films.Furthermore,it is also a conductive dispersant of carbon materials for the preparation of high-quality conductive ink and electrode materials.