TY - JOUR A1 - Schmid, Markus A1 - Sängerlaub, Sven A1 - Miesbauer, Oliver A1 - Jost, Verena A1 - Werthan, Johannes A1 - Stinga, Camelia A1 - Samain, Daniel A1 - Stramm, Cornelia A1 - Noller, Klaus A1 - Müller, Kajetan T1 - Water Repellence and Oxygen and Water Vapor Barrier of PVOH-Coated Substrates before and after Surface Esterification T2 - Polymers N2 - This study investigates chemical grafting with fatty acid chlorides as a method for the surface modification of hydrophilic web materials. The resulting changes in the water repellence and barrier properties were studied. For this purpose, different grades of polyvinyl alcohol (PVOH) were coated on regenerated cellulose films (“cellophane”) and paper and then grafted with fatty acid chlorides. The PVOH grades varied in their degree of hydrolysis and average molecular weight. The surface was esterified with two fatty acid chlorides, palmitoyl (C16) and stearoyl chloride (C18), by chemical grafting. The chemical grafting resulted in water-repellent surfaces and reduced water vapor transmission rates by a factor of almost 19. The impact of the surface modification was greater for a higher degree of hydrolysis of the polyvinyl alcohol and for shorter fatty acid chains. Although the water vapor barrier for palmitoyl-grafted PVOH was higher than for stearoyl-grafted PVOH, the contact angle with water was lower. Additionally, it was shown that a higher degree of hydrolysis led to higher water vapor barrier improvement factors after grafting. Furthermore, the oxygen permeability decreased after grafting significantly, due to the fact that the grafting protects the PVOH against humidity when the humidity is applied on the grafted side. It can be concluded that the carbon chain length of the fatty acid chlorides is the limiting factor for water vapor adsorption, but the grafting density is the bottleneck for water diffusing in the polymer. KW - poly(vinyl alcohol) KW - chemical grafting KW - esterification KW - barrier properties KW - water repellence Y1 - 2014 UR - https://opus4.kobv.de/opus4-hs-kempten/frontdoor/index/index/docId/150 SN - 2073-4360 VL - 6 IS - 11 SP - 2764 EP - 2783 ER -