This work describes the synthesis and properties of new oligmeric, polymeric and macrocyclic ether sulphones bearing carboxylic groups in the side chains.
Linear ether sulphones
Several oligo(ether-sulphones) with carboxylic groups in the side chains and either chlorophenyl-endgroups (4a-h) or phenolic endgroups (5a, 5b) were synthesized by polycondensation of different relative amounts of bis(4-chlorophenyl)sulphone (2) and 4,4-bis(4-hydroxyphenyl)pentanoic acid (1). The molecular weight distributions of the oligo(ether-sulphone)-fractions of 4a-h were estimated by GPC, elementary analysis and NMR-spectroscopy. The glass transition temperatures of the oligo(ether-sulphones) increase with the molecular weight of the oligomers.
New macrocyclic arylene ether sulphones bearing one or two carboxylic groups (8 and 9 respectively) were prepared by use of pseudo high dilution technique. In a first step, 4,4-bis(4(4-chlorophenylsulphonyl)-phenoxy -4-phenyl)pentanoic acid (7) was prepared from 4,4-bis(4-hydroxyphenyl)pentanoic acid (1) and an excess of bis(4-chlorophenyl)sulphone (3). Then, the purified trimer 7 was cyclocondensed with 4,4-bis(4-hydroxyphenyl)pentanoic acid (1), yielding the bifunctionalized macrocycle (8), and with 2,2-bis-(4-hydroxyphenyl)propan (2) to get the monofunctionalized mocrocycle (9). The existence of the ring shaped molecule was proved by use of MALDI-TOF, NMR- and IR-spectroscopy.
The free carboxylic groups of 8 were used to build up a polyamide (under the conditions of Yamazaki) that contain the macrocycle in the main chain and 4,4´-diaminodiphenylmethane as an aromatic diamine-component.
The nucleophilic telechelic oligo(ether sulphone)s with free carboxylic groups in the side chains and phenolic endgroups (5a, 5b) have been uesd for building block copolymers. The carboxylic groups were esterified with methanol (16a, 16b). As electrophilic prepolymers the OH-endgroups of several poly(ethylene glycol)s and poly(butylene glycol)s were mesylated to incorporate good leaving endgroups. For coupling of these two prepolymers a nucleophilic aliphatic condensation reaction was carried out. The resulting block copolymers contain both, the hydrophilic polyethers as soft segments and the relatively rigid and hydrophobic oligo(ether sulphone)s as hard segments. GPC-, NMR-, FTIR- measurements and the data from thermal investigations of the block copolymers (19a-19h) are discussed. Additionally, the block copolymer 19h was fractionated and characterized by use of GPC-FTIR spectroscopy.
The poly(ether-sulphone)s with carboxylic groups in the side chains can also be applied as polyanions. Therefore this poly(ether-sulphone)s and some modified oligo(ether-sulphone)s with carboxylic groups and additionaly sulfonated acid gropus have been used for building multilayers. The method for the multilayer build-up is based on physisorption of the polyelectrolytes. The multilayers obtained are characterized by UV-Vis spectrometry. In dependence of the used polyanions multilayers with more than 30 double layers have been realized.
Another part of this work describes the building of graft and hyperbranched polymers. Using the reactivity of the carboxylic groups in the side chains, the oligo(ether-suphone)s have been condensed with different aromatic carbonic acids. Reacting with 4-aminobenzoic acid graft polyamide in the side chains were obtained. Condensation of trifunctional 5-aminoisophthalic acid onto the polysulphon yielded a polymer with hyperbranched side chains. By using NMR-, FT-IR and GPC-measurements we prooved the successful condensation reactions.