Co-polyamides

Notes EVA, ethylene vinyl acetate LLDPE-MAH, maleic anhydride grafted linear low-density polyethylene COPA, co-polyamide. 

The EVA and co-polyamide (COPA) layers are resolved quite well by FTIR transmission imaging (Figure 12), but the 5 pm linear low-density polyethylene/ maleic anhydride grafted (LLDPE-MAH) layers cannot be detected in this mode. 

The earlier example of the formation of a poly(urethane-co-urea) showed the change in properties made possible by including a comonomer (in that case a difunctional amine) together with the usual diol for reaction with a di-isocyanate. This can be extended to a wide range of step polymerizations where an additional reactant is added. Examples could be the use of two AB-type monomers (e.g. amino acids) or two AA (e.g. diacids) to react with one BB (a diamine) to form co-polyamides. Seveml features of step polymerization help in understanding the resultant copolymer. For example, since high-molar-mass polymer is formed only late in the reaction, the composition of the copolymer will be that of the feed ratio of the monomers. 

Polyamide the abbreviation PA is normally followed by a number, a combination of numbers, a letter, or a combination of letters and numbers. A single number refers to the polyamide from an a,co-amino acid or its lactam. A combination of two numbers is often separated by a comma. The first number following the symbol PA indicates the number of methylene groups of aliphatic diamines and the second number the number of carbon atoms of aliphatic dicarboxylic acids. An I stands for isophthalic acid and a T for terephthalic acid. For example, co-polyamide from caprolactam, hexamethyle-nediamine condensed with isophthalic and terephthalic acids... 

There are three types of major commercial aramid fibres in the market para-aramid (or p-aramid, poly-(p-phenylene terephthalamide), PPTA), meta-aramid (or m-aramid, poly-(meta-phenylene isophthalamides), MPIA) and co-polyamides fibres. 

In 1975, Russo reported that when N,N -diphenylbenzidine or N,N -diphenyl-l,4-phenylene diamine were interfacially polymerized with a mixture of 1,2,5-thiadiazole and 3,4-furan dicarbonyl chloride, co-polyamides were obtained having good heat resistance, dielectric properties, and mechanical properties, "comparable to those of other construction materials."... 

Co-polyamides have been prepared from bis(4-aminocyclohexyl) methane and various other diamines and diacids or diacid chlorides. Little has been reported in the open literature on the use of 2,2-bis(4-aminocyclohexyl) propane in polymerization probably because it is a relatively new monomer. Both monomers find use in the preparation of copolyamides which are amorphous and therefore transparent. 

Carbon-13 n.m.r. sequence analysis on aliphatic homo and co polyamides the nylon 6,6 type have been reported. ... 

Grilon BA 140 (produced by EMS) is another new development in bicomponent fiber made of a PA core, sheathed with co-polyamide, and these fusible adhesive fibers are used for the reinforcement and bond nonwovens, spun yams, and textiles. The sheath layer melts at 135°C, while the core remains solid until a temperature of 220°C. Through use of bicomponent fibers, fusible adhesive can be distributed very finely throughout the supporting fibers. The solid core provides support for the nonwovens both during and after bonding [43]. 

Centeno TA, Fuertes AB (2000) Carbon molecular sieve gas separation membranes based on poly(vinylidene chloride-co-vinyl chloride). Carbon 38 (7) 1067-1073 Xiao Y Chung T-S, Guan HM, Guiver MD (2007) Synthesis, cross-linking and carbonization of co-polyamides containing internal acetylene units for gas separation. J Membr Sei 302 (1-2) 254-264... 

The Radici Group, Italy, produces a full range of products including polyamide 6 and 66 (sold under the brand name Radilon), co-polyamides and blends. Radici also owns the PA6 and 66 Heramid brands following its takeover of the Franz Rauscher company. 

Bi-component fibres can be made from two variants of the same generic fibre (two types of polyester (PES), polyethylene terephthalate (PET), copolyester (coPES), polyacrylonitrile (PAN), polyamide (PA), polyethylene (PE) and polypropylene (PP)). The fibres can also be made from two different polymer compositions, e.g. PET/PA, PA/Spandex, etc. Different types of polymers, such as polyester, polyamides, polystyrene, polyurethane, polyolefines, polylactic acid, co-polyamides and soluble co-polyesters, have been used to spin bi-component fibres. 

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