Polyamides surface hydrolysis

Keywords Cutinase Polyacrylonitrile Polyamide Polyethyleneterphthalate Surface hydrolysis... 

Almansa E, Heumann S, Eberl A et al (2008) Surface hydrolysis of polyamide with a new polyamidase from Beauveria brongniartii. Biocatal Biotrans 26 371-377... 

Chapter 5 shows that the application of hydrolytic enzymes is a powerful yet mild strategy to directly improve polymer surface properties (i.e. hydrophilicity) or activate materials for further processing. The surface hydrolysis of polyamides (PA), polyethyleneterphthalates (PET) and polyacrylonitriles (PAN) is discussed, as well as the mechanistic details on the enzymatic surface hydrolysis. The mechanistic data, combined with advances in structural and molecular biology, help to explain different activities of closely related enzymes on polymer surfaces. 

Limited surface hydrolysis ofpoly(alkyleneterephthalate)s (PAT), polyamides (PA) and polyacrylonitriles (PAN) by enzymes increases their hydrophilicity which is... 

In theory PU should be very active towards bonding, with an activated N-H and a carbonyl group, as described for polyamides. However PUs are never that easy to bond and could be due to surface oxidation and/or surface hydrolysis, it is normal to remove the surface, degrease and prime before the surface is too old. 

Although the hydrophobic surface of nylon membranes may be improved by hydrolysis or chemical modification, composite polyamide membranes are preferred in chromatographic applications. Klein et al. [42] prepared polyamide microporous membranes by modification of terminal amino groups. Covalent binding of a polyhydroxyl-containing material to the polyamide membrane increases the density... 

Recently, a new approach using enzymes to modify material (or nanomaterial) surfaces has been developed. This approach utilizes enzymatic hydrolysis or degradation to mildly etch the material surfaces and thus CTeate desirable surface structures or properties [45]. Many polymers, including polyvinyl chloride (PVC), polyaayloni-trile, polyethylene terephthalate, and polyamides, have been modified by this method. In a recent study, PVC tubes were soaked in Rhizopus arrhizus lipase to create nanometer surface features that exhibited antibacterial properties [60]. Enzymatic modification demonstrates great potential and promise for biomedical and nanomedicine applications due to its biocompatible, environmentally friendly, and simple process. 

Due to the presence of moisture on the surface or environment, NO forms HNOj and HNO. Hydrolysis of polyamide-6 may occur in acidic conditions. Water protonates amide and hydroxyl functionalities and results in chain scission. The attack might have occurred in the amorphous region of the crystal structure, where the water diffusion occurs in a limited manner by the dispersed clay platelets. 

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