Synthesis and Thermal Properties of Polyamide 6-block-Poly(cyclohexylmaleimide)

Abstract

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 ...

Nude and Modified Electrospun Nanofibers, Application to Air Purification

“…PA-6 is a versatile thermoplastic polymer, very popular for the excellent mechanical properties such as impact strength, stiffness and high thermal degradation temperature, due the strong interchain attraction derived from the polarity of amide groups [ 132 ]. Among the different types of polyamides, nylon 6,6 is one of the most well known and commercialized aliphatic polyamides [ 133 ].…”

“…Among the different types of polyamides, nylon 6,6 is one of the most well known and commercialized aliphatic polyamides [ 133 ]. Several methods of polymerization have been used to synthetize PA-6, among them the transesterification by combination [ 134 ], direct polycondensation with triphenylphosphine melt-polymerization of block copolymers consisting of PA6 and Poly(N-cyclohexylmaleimide) (PCHMI) [ 132 ] and anionic ring-opening and condensation reactions ( Figure 14 ) [ 135 ]. In the same way, different monomers can be used, such as poly(4,4′-diphenylsulfone terephthalamide) (PSA), poly( p -diphenyl oxide terephthalamide) (POA), poly( p -diphenylmethane terephthalamide) (PMA), and isophthaloyl chloride (IPC) to obtain nylon 6,6 copolymers [ 136 ].…”