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A series of sulfonated polyimides (SPIs) were synthesized from a sulfonated diamine of 4,4′‐bis(4‐aminophenoxy) biphenyl‐3,3′‐disulfonic acid (BAPBDS), common nonsulfonated diamines, and various tetracarboxylic dianhydrides including 1,4,5,8‐naphthalene tetracarboxylic dianhydride (NTDA), 3,4,9,10‐perylene tetracarboxylic dianhydride (PTDA), 4,4′‐binaphthyl‐1,1′,8,8′‐tetracarboxylic dianhydride (BTDA), 4,4′‐ketone dinaphthalene 1,1′,8,8′‐tetracarboxylic dianhydride (KDNTDA), and isophthatic dinaphthalene 1,1′,8,8′‐tetracarboxylic dianhydride (IPNTDA). Their membrane properties were investigated to clarify the effects of the dianhydrides. They displayed reasonably high mechanical properties, thermal stability, and proton conductivity. The dianhydrides with flexible and non‐coplanar structure (IPNTDA > KDNTDA > BTDA) led to the better solubility of the SPIs than those with rigid and coplanar one (NTDA, PTDA). The dianhydride with the smaller molecular weight led to the larger value of the number of sorbed water molecules per sulfonic acid group (λ) in membrane, that is, NTDA (λ: 17) > PTDA (15) > BTDA (14) > KDNTDA (12) > IPNTDA (10), and as a result let to the larger proton conductivity in water. All of the BAPBDS‐based SPIs showed the anisotropy in membrane swelling and in proton conductivity, of which the degree hardly depended on the dianhydride moieties. The water stability of SPI membranes against the aging in water at 130 °C for 192 h was in the order, PTDA = NTDA ≧ BTDA > KDNTDA > IPNTDA. The hydrolysis stability of polymer chain was similar between the BTDA‐ and KDNTDA‐based SPIs. These results are discussed. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 905–915, 2010

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ABSTRACT:Two polyamide 6 (PA6) radical initiators (PA6ini), AI and AlA types (A: PA6 segment, I: azo group), were prepared from 4,4'-azobis-2-cyanopentanoyl chloride and PA6 prepolymers having controlled average molecular weights. Various PA6-hlock-vinyl polymers were synthesized by radical polymerizations of vinyl monomers, such as styrene, methyl methacrylate (MMA), butyl methacrylate, hydroxyethyl methacrylate and vinyl acetate (VAc) using PA6inis. The polymerizations of MMA proceeded homogeneously in phenol/methanol (4,01/1,01), formic acid and 2,2,2-trifluoroethanol. The overall initiation efficiency of PA6ini (AI type) was 0.11 for the polymerization of MMA in formic acid at 60oC for 24h. Poly(MMA) in the polymer synthesized using PA6ini was dependent on concentration, molecular weight and type of PA6ini. PA6-block-poly(VAc) was synthesized in 2,2,2-trifluoroethanol (TFE), but not in phenol/methanol (4,01/1,01).KEY WORDS Polyamide 6 Radical Initiator / Macroazoinitiator / Block Copolymer / RadicalPolymerization I Vinyl Monomers I Polyamide 6 (PA6) has many industrial applications. Block copolymers from P A6 and other polymers, such as vinyl polymers, polyethers, polyimides and polyesters, were synthesized, expecting new properties.

ABSTRACT:Block copolymers consisting of poly( cyclohexylmaleimide) (PCHMI) and polyamide 6 (PA6) were synthesized and thermal properties were measured. Carboxyl group-terminated PCHMis initiated by 4,4'-azobis-4-cyanopentanonic acid (ACPA) under several conditions had different r.s, depending on the molecular weight of PCHMI. Copolymers consisting of PA6 and PCHMI were prepared by melt-polymerization of 6-aminocapronic acid and PCHMI. The copolymers contained ABA and ABjudging from 1 H NMR and reduced viscosity measurements. T.s of the copolymers were independent of T• of the original PCHMI, and increased with PCHMI content in the copolymers.KEY WORDS Polyamide 6 I Poly(cyclohexylmaleimide) I Block Copolymer I Melt-Polymerization I Thermal Properties I Polyamide 6 (PA6) has many industrial applications, and block copolymers from PA6 and other polymers, such as vinyl polymers, polyethers, polyimides, and polyesters, were synthesized to expect new properties. 1 However, major vinyl polymers copolymerized with PA6 are poly(styrene) 2 -7 and rubbers such as poly(butadiene-acrylonitrile ), 8 -11 poly( styrenebutadiene), 12 • 13 poly(butadiene ) 6 · 14 -16 and poly(isobutylene).17 There have been few studies on the synthesis and characterization of block copolymers of PA6 with vinyl polymers, except poly(styrene) and rubbers.The polymerization of s-caprolactam (CL) has been initiated with end groups of prepolymers consisting of other polymers for prepolymers having amino or carboxyl end groups. 1 In the preparation of block copolymers, initiators such as dicarboxylic acids, waminocarboxylic acids, or water were often added to the system to increase the rate of copolymerization. 1 In general, however, the preparations were carried out above the melting points ( T m) of copolymers. 1 Thus, thermal stability of the prepolymers is required.Poly(N-substituted maleimide)s (poly(RMI)s) have usually good thermal stability and various properties depending on the N-substituents. 18 Since homopolymers are brittle, copolymers with other vinyl monomers were usually used. The unique thermal and optical properties, and characteristic of separation of the copolymers have been reported. 18Poly(N-cyclohexylmaleimide) (PCHMI) has a high softening point 19 and thermal decomposition temperature. 20 Block copolymers from P A6 and PCHMI are of great interest from the point of synthesis and thermal properties. The present paper describes the synthesis of PA6-block-PCHMI from CL, 6-aminocapronic acid (ACA) and carboxyl group-terminated PCHMI obtained from the radical polymerization of CHMI with 4,4'-azobis-4-cyanopentanonic acid (ACPA). Thermal properties of the copolymers were investigated by differential scanning calorimetry (DSC) and dynamic mechant To whom all correspondence should be addressed. 500 ical spectrometry. EXPERIMENTAL MaterialsCL (Ube Ind., Ltd.) was commercial-grade. CHMI (melting point; 89oC) was prepared as described earlier. 19 ACA, m-cresol, methanol, tetrahydrofuran (THF), 1,4-dioxane (DOX) and 1-methyl-2-pyrrolidinone ...