Herstellung definierter Polymerstrukturen durch 'Atom transfer radical polymerisation'
The present thesis deals with the preparation of well-defined polymer structures based on styrene by means of atom transfer radical polymerisation (ATRP). The focus is placed on the synthesis of novel block copolymers, synthesis and coupling of telechelic polymers as well as on the preparation of soluble styrene copolymers that can be cross-linked thermally and photochemically.Two new classes of block copolymers containing polystyrene segments were developed: block copolymers with polystyrene and polycarbonate segments (PS/PC) and block copolymers with PS and poly(phenylene oxide) segments (PS/PPO). For this purpose, hydroxy telechelic PC or PPO were converted into ATRP macroinitiators. These macroinitiators were used for the ATRP of styrene.Atom transfer radical coupling (ATRC) was investigated as a coupling method. ATRC was not only used for chain extension of PS, but was employed for the first time to the coupling of diblock and triblock copolymers to form multiblock copolymers. Whereas chain degradation of block copolymers containing PC segments was observed, PPO/PS block copolymers were converted successfully into multiblock copolymers under ATRC conditions. Two concepts were used for the synthesis of mono- and bifunctional telechelic PSs with unsaturated end groups: the combination of ATRP with an addition-fragmentation-chain-transfer reagent (AFCT) and the chain analogous reaction of PS prepared by ATRP with methacrylic acid. In general, the main disadvantage of the reaction of telechelic polymers is the low concentration of end groups in the reaction mixture. To improve the suitability for cross-linking, polymers carrying reactive double bonds in their side groups as cross-linkable materials should therefore be an alternative. It was shown that AMA can be homopolymerised to soluble polymers via ATRP under suitable conditions. Copolymerisation of AMA and styrene yields soluble copolymers which were cross-linked both thermally and photochemically and therefore offer a potential for applications such as coating and lithography. Thin films of these copolymers on silicon and titanium/nickel alloy surfaces were microstructured by application of photolithography.Using ATRP of AMA and the aforementioned bifunctional macroinitiators based on PC and PPO, these high performance thermoplasts were analogously transformed into cross-linkable triblock copolymers.
info:eu-repo/classification/ddc/540, Chemie, vernetzbare Präpolymere, Allylmethacrylat, Atom-Transfer-Polymerisation, Blockcopolymere, Telechele Polymere, Polystyrol, Polycarbonate, Atom Transfer Radical Polymerisation (ATRP), block copolymers, telechelic polymers, cross-linkable prepolymers, allyl methacrylate
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