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RESEARCH PRODUCT

Some New Copolymers by Ionic Polymerization

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In the first part the cationic polymerization of a homologous series of cyclic ether–acetals with ring sizes of 11, 14, and 17 atoms is described. During the polymerization of triethylene glycol formal (TGF) an equilibrium is reached and besides high polymers cyclic oligomers are formed. The oligomers and the polymers are built up of a regular sequence of one oxymethylene unit and three oxyethylene units –[–(OCH2) (OC2H4)3–]–x. They are therefore be labelled a “sequenced copolymer.” The equilibrium concentrations of the cyclic oligomers with a polymerization degree from 2 to 15 follow the Jacobson–Stockmayer equation. The 14- and 17-membered monomers POC and HOC forms cyclic oligomers and high polymers of the general formula –[–(OCH2)1 (OC2H4)y–]–x with y=4 and y=5, respectively. The melting points of these sequenced copolymers with y=1—5 are determined. Furthermore, the cationic polymerization of 1,3-dioxacycloundecane (OMF) and 1,3,6,11-tetraoxacyclotridecane (DDF) was studied. 1H and 13C NMR spectra show that again regular copolymers are formed: In the first case an alternating 1:1 copolymer –[–(OCH2) (OC8H16)–]–x, in the latter case a terpolymer with the regular sequence –[–(OCH2) (OC2H4) (OC4H8) (OC2H4)–]–x. The second part deals with the polymerization of 2-isopropenylnaphthalene. With maleic anhydride at room temp a charge-transfer complex is formed; at higher temp a Diels–Alder reaction occurs. Only at low temp with UV initiation or redox initiation a copolymer is formed. With cationic catalysts a mixture of dimer, trimer, and tetramer but no polymer is obtained. The anionic polymerization yields polymers with molecular weight from 10,000 to 300,000 and melting points of 280°C and glass-transition temp of 220°C. By “living polymer” techniques block copolymers are available.