Synthesis And Applications Of Sunlight-Degradable Pyridinemethanol Ester-Contained Supermolecular Polymers

Photodegradable supramolecular polymers not only have the special properties of traditional photodegradable polymers,but also have dynamic and controllable properties,which are expected to be further developed and applied in the fields of drug deliveries,tissue engineering and"transient"electronic devices.The degradation behavior mainly depends on the chemical bond breaking process in the chain.At present,the research on photo-degradable materials is mainly focused on degradation by ultraviolet light,while the research on visible light and even sunlight is relatively few.Compared with high-energy light source,long-wavelength light?>400 nm?is a relatively safe light source,and about 43%of sunlight is visible light,which is a rich and low-cost energy source,which provides the possibility of large-scale degradation products.N-alkylpyridinium ester?NAPEs?is a typical visible light?452 nm?responsive group.Under light irradiation,the C-O bond of alkylated pyridinium ester is chemically cleaved by photo-induced mediate electron transfer.The photodegradable polymer can be successfully produced by introducing this group into the polymer chain through a special structural design.Yet,how to simply synthesize visible light and even sunlight degradable building blocks is still a challenging task in this field.Based on these,the synthesis and application of NAPEs-based supramolecular polymer materials are explored in this paper.The contents are as follows:?1?A sunlight-degradable autonomous self-healing supramolecular elastomer for flexible electronic devicesA photodegradable self-healing supramolecular elastomer?SDSE?was prepared from NAPEs based on the reversible supramolecular recognition process between amantadane and?-cyclodextrin nanogel??-CD?.Then the mechanical properties,self-repairing properties and mechanism,photodegradable properties and mechanism of SDSE were studied in detail,and its application in self-repairing strain sensor and flexible degradable supercapacitor was explored.It was found that the as-synthesized elastomer possesses merits of high mechanical strength,excellent stretchability?>1500%,strain?,efficient self-healing?>85%@60 min?,ultrastability against electrolytes,photodegradation properties.The self-healable strain and pressure sensors feature exceptionally high sensitivity?e.g.,0.1%in capacitance at 0.2 kPa?and fast response to detect human body motions.The elastomer and this supercapacitor can be degraded upon the exposure to sunlight irradiation in 48 h at very mild conditions.Therefore,it is anticipated that such a novel strategy and the as-prepared supramolecular elastomer can inspire further applications in the multidisciplinary fields of materials science,electronics,etc.?2?Synthesis and exploration of a sunlight-degradable supramolecular polymer precursors for porous materialsPasserini three component reaction can assemble isocyanides,aldehydes,and carboxylic acids into an?-acyloxyamide.It has been found that a rational design of the aldehyde moiety can introduce NAPEs into the material in one step.In this chapter,we designed and synthesized aldehyde containing pyridinium ester group?IPA?,carboxylic acid?RAP?,PEO-NH₂,explored the synthesis of cyanide?PEO-NC?.The product structure was characterized by ¹H NMR and¹³C NMR,and the molecular weight of RPA was characterized by GPC(7768 g moL^-1,polymerization degree was 72,and the dispersion index was 1.21).It is expected that NAPEs based materials and this method can increase the utilization of sunlight,providing ideas for the preparation of porous materials.