Aromatic polyamides Poly

Introduced in 1972, the whoUy aromatic polyamide, poly i ra-phenylene teraphthalamide), termed aramid, was the subject of extensive evaluation as a tire cord in all types of tires (8,14). As of the late 1990s, however, only specialized appHcations have emerged for aramid tire cord that draw on their high strength-to-weight ratio to produce tires with lower weight (16). 

Nylon 6 is the homopolymer of caprolactam, and Kevlar is an aromatic polyamide, poly-p-phenylene terephthalamide. 

M. Arpin and C. Strazielle, Characterization and conformation of aromatic polyamides poly(l,4-phenylene terephthalamide) and poly(p-benzamide) in sulphuric acid. Polymer, 18 (1977) 591-598. 

In this chapter, therefore, some examples of the structural and dynamic analyses performed for polyamides such as nylon 4, 6, 7, 11 and 66, will be described including the oriented fibers of aromatic polyamides, poly(m-phenylene isophthalamide) (PMIA) and poly(4-methyl-m-phenylene tereph-thalamide) (P4-MPTA). 

A crystalline, partially aromatic polyamide, poly-m-xylylene-adipamide, (also known as MXD-6) with repeat units of... 

OOPar Park, W., Mark, J. E. Reinforcement of the aromatic polyamide poly (trimethyhexamethy-lene terephthalate) Comparisons among blended ex situ silica with and without a bonding agent and in situ generated siUca. Polym.-PlasL Technol. Eng. 39 (2000) 5, 783-792. 

Quite early solution blend work by Takayanagi et al. [83] of rigid aromatic polyamides (poly(p-phenylene terephthalate)) (PPTA) and flexible aliphatic polyamides, nylon 66 and nylon 6 (the latter will be discussed here) has been instrumental in developing the concept of molecular composites and although this lies more in the realm of lyotropic blends, it is often cited in the literature with regard to the effect of the PLC on the crystallization of other components in blends. PPTA has the structure... 

Lin and co-workers [47] reinforced PU elastomers with an entirely rigid aromatic polyamide, poly(w-phenyleneisophthalamide). The block copolymers formed exhibited glass transition temperatures (Tg) under 0 °C. Such block copolymers have improved reinforcing affect as shown by both their tensile strength and elongation when compared with the virgin PU. 

The combination of photoscission, photo-oxidation, and photorearrangement means that even very high performance polymers, such as epoxy resins, aromatic polyethers polyketones, and polysulfones, and the aromatic polyamides poly(l,3-phenylene isophthalamide) and poly(l,4-phenylene terephthalamide) (Nomex and Kevlar respectively) will degrade significantly on solar exposure. For example, it has been shown (108) that poly(phenylene oxide) and polysulfone both lose about 50% of their initial tensile strength after 2 years of outdoor exposure in Queensland. 

Among the aromatic polyamides, poly(l,4-benzamide) (PBA) and poly(/)-phenylene terephthalamide) (PPTA) were the first cotmnerdal aramid fibers spinned from lyptropic LC solutions (Chapter 5.19). 

High modulus fibers from lyotropic aromatic polyamides, poly(p-phenylene terephthalamide) (PPTA), were first conunercialized imder the Kevlar trademark by DuPont [414]. The aromatic polyamides, or aramids, are produced by a dry jet-wet spinning process where the nematic structure in solution is responsible for the high modulus fiber performance [415-419]. Another class of lyotropic fibers, also produced by dry jet-wet spinning, are the rigid rod polymers developed as part of the U.S. Air Force Ordered Polymers Program [420-424]. The most conunon of these ordered polymers, poly(p-phenylene benzobisthiazole) (PBZT), is difficult to process, but it exhibits the highest tensile properties of all the LCP fibers produced to date. 

Other recent studies which involve and illustrate the power of the FTIR technique include surface studies of PVC systems with PMMA [192] and poly(e-caprolactone) (PCL) [193, 194] PVC with styrene/acrylonitrile copolymers [195] polyester/nitrocellulose [196] EVA copolymer with PVC and chlorinated polyethylene (CPE) [197] and interactions in blends involving p-sulphonated polystyrene [198, 199]. FTIR techniques have been used to map the phase diagram of an aromatic polyamide-poly(ethylene oxide) blend [200], while microscopy-FTIR has been used to obtain information on intermolecular interactions and conformational changes in specific domains in functionalised polyolefins with PVC or polystyrene [201]. Segmental motions and microstructure studies from combined DSC and FTIR measurements have been used to interpret solid-state transitions in miscible rubber blends [202]. 

Aramid pora-Aramid Aromatic polyamide Poly-paraphenylene terephthalamide Aromatic nylon... 

Sugi, R., Hitaka, Y., SeMno, A. et al. (2003b) Bidirectional propagation of chain-growth polycondensadon Its application to poly(ethylene glycol)-aromatic polyamide-poly(ethylene glycol) triblock copolymer with low polydispersity. Journal of Polymer Science Part A-Polymer Chemistry, 41,1341-1346. 

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