Preparation And Applications Of Photobase Generators

Aiming at the development of new photobase generators (PBGs) and photoimageable sacrificial materials for radiation curing and photoresist applications, this thesis research explores the potential of bicyclic guanidine salts as a new class of PBGs and their uses as photocatalysts in photoinitiated base-catalyzed polymerizations, polymer cross-linking and polymer thermal degradation.A strong bicyclic guanidine base, 1,5,7-triaza-bicyclo[4.4.0]dec-5-ene(TBD), with allyl as chromophores are simple synthesized to new photobase generators. Alkyl, phenyl and unsaturated alkyl are selected as different types chromophores to fully represent the nature and application of TBD derivatives. Three types of TBD derivatives all have high yield and purity. This article tested a series of characterization of three types of products include:NMR, IR, solubility, thermal stability, UV absorption and concentration, cation, different solvents influence on the UV absorption, also the product of fluorescence quantum detection production rate, and proven products, light trigger mechanism.After testing, can be shown that this synthesis of the various properties of three new PBGs practical applications are in line with industry needs:The right structure; high yield, purity and solubility; Thermal stability is much higher than the commonly used photo initiator catalysts; UV range meet the requirements of the microelectronics industry, especially for photoresist industry; Quantum yield average of 0.5, significantly higher than the industrial requirements of 0.1, and the existing PBGs quantum yields, indicating that the good efficiency of photolysis; Product decomposition mechanism of the light trigger is simple, light trigger conditions are right, in the exposure of 1Omin, the three types of products can produce alkali catalyst TBD, which applied to the field of microelectronics and coating.A strong bicyclic guanidine base, TBD, is photo-generated from its derivatives and can effectively catalyze the transesterification reaction between the ester and hydroxy groups in polymers. Accordingly, with TBD derivatives as photobase generators, a water-soluble polymer blend, namely poly(1-vinylpyrrolidone-co-2-dimethylaminoethyl methacrylate) and 2-hydroxyethyl cellulose, has been developed as a potential eco-friendly photoresist. This photoresist system uses only water as a solvent and as a developer, rather than organic solvents and aqueous alkaline developers. The effects of the amount of photobase generator, polymer composition and photolithographic conditions on the photo-induced crosslinking and patterning of water-soluble polymers were studied.Accordingly, with TBD derivatives as photobase generators, Photoinduced cross-linking of 2-hydroxyethyl cellulose and poly(methyl methacrylate), photoinduced surface modification of cellulose were also studied.