Polyamide resins Aramid

Electrospinning is applicable to a wide range of polymers like those used in conventional spinning, that is, polyolefine, polyamides, polyester, aramide, and acrylic, as well as biopolymers like proteins, DNA, and polypeptides, or others like electrically conducting, photonic and other polymers such as poly(ethylene oxide] (PEO], DNA, poly(acrylic acid] (PAA], polyQactic acid] (PEA], and also collagen, organics such as nylon, polyester, and acryl resin, and poly(vinyl alcohol] (PVA], polystyrene (PS], polyacrylonitrile (PAN], peptide, cellulose, etc. 

Aramid fibre dipped in liquid phenolic, polyester or polyamide resin to form a paper can be used to form a honeycomb (NOMEX). Properties are dependent on paper thickness, cell geometry and size. Advantages of non-metallic honeycomb cores are absence of internal corrosion and impact resilience. 

It has been known since the early days that behavior of the aromatic polyamides (aramids or PARA) critically depends on the type of isomeric substitutions — para resulted in crystalline, while meta in amorphous resins [Kwolek et al, 1962]. 

Aramid belongs to the family of polyamides, but the bonding of matrix (resin) appears to be more difficult than on PA6 (nylon). In order to improve the behavior of the fiber, it is treated with finishing substances. Nevertheless, the compressive strength reaches only 25 % of the tensile strength. 

Aramid fibers are highly oriented fibers derived from aromatic polyamides, with Kevlar and Nomex as two prominent examples. The woven fabric of aramids combined with phenolic resins produces high-performance composites for ballistic applications, where the projectile energy is mainly absorbed by the fiber with a high strength and modulus (Gardziella et al, 2000). 

The tire cord fabric is pulled of woven fabric and passes through an impregnating bath with a resorcinol-formaldehyde-latex solution that improves the adhesiveness on the rubber. This impregnating is sufficient for viscose and polyamide, but polyester and aramid have to be pretreated additionally with bonding agents based on epoxy resin. 

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