Technische Biopolymere

Endres, Hans‐Josef; Siebert-Raths, Andrea

doi:10.3139/9783446421042

Cited by 74 publications

(31 citation statements)

References 6 publications

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“…The utilization of biopolymers in packaging applications is increasing, with biopolymers substituting or complementing conventional fossil-based polymers [1][2][3][4][5][6][7][8]. Biopolymers are defined as being based on renewable resources and/or being biodegradable [9]. The most available renewable raw material is cellulose, which is mainly acquired from wood, cotton and annual plants [1].…”

Section: Introductionmentioning

confidence: 99%

Water Repellence and Oxygen and Water Vapor Barrier of PVOH-Coated Substrates before and after Surface Esterification

et al. 2014

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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 OPEN ACCESSPolymers 2014, 6 2765 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.

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Section: Introductionmentioning

confidence: 99%

Water Repellence and Oxygen and Water Vapor Barrier of PVOH-Coated Substrates before and after Surface Esterification

et al. 2014

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“…Significant amounts of wood flour, polymer, and additives (e.g., antioxidants) have been applied in order to enhance the biological durability of WPCs (Chow et al 2002;Verhey et al 2002;Silva Guzman 2003;Klyosov 2007;McDonald et al 2009;Morrell et al 2010). The ratio of wood flour to plastic matrix ratio determines the biological durability of WPCs (Silva Guzman 2003).…”

Section: Introductionmentioning

confidence: 99%

Improvement of Biodegradation of Wood Plastic Composites using Rice-Bran Mixture

Choi¹,

Lee²,

Yoo³

et al. 2016

BioResources

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Wood-plastic composites (WPCs) are currently discarded using incineration treatment, which is very expensive. Hence, this study was performed to improve the biodegradation of WPCs, such that they could potentially be buried after use, and to estimate their bending strength. A biodegradation test (determining the ultimate aerobic biodegradability of plastic materials under controlled composting conditions) was performed according to ISO 14855-1. Two groups of specimens were prepared using rice-bran mixture as the bioresource. One group contained ricebran mixtures of 5, 7.5, and 10 wt.% instead of wood flour contents, and another group contained rice-bran mixtures of 8, 16, and 24 wt.% instead of the talc component. During the 20 days of the biodegradation experiment, the WPC (control) showed 18% biodegradation, and 7.5%-rice-bran-mixture-added specimen showed the highest biodegradation of 32%. Furthermore, the bending strength (MOR) was increased by up to 140% by adding rice-bran mixture as a biodegradable component. Therefore, the rice-bran mixture improved the biodegradation and mechanical properties of WPCs.

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“…NaOCl, an oxidant and leach, oxidizes organic partial structures and causes alkaline hydrolyzes. Like NaOH, it removes proteins and lipids, but no carbohydrates [Endres and Siebert-Raths, 2009]. In addition, alkaline agents such as NaOH and NaOCl split off acetyl groups from chitin and that way convert water-insoluble chitin into watersoluble chitinosan [Nachtigall, 2002].…”

Section: Effect Of Treatments On Organic Mattermentioning

confidence: 99%

Impact of sample pretreatment on the measured element concentrations in the bivalveArctica islandica

Krause-Nehring

Klügel

Nehrke

et al. 2011

Geochem. Geophys. Geosyst.

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[1] Correlating metal to calcium (Me/Ca) ratios of marine biogenic carbonates, such as bivalve shells, to environmental parameters has led to contradictory results. Biogenic carbonates represent complex composites of organic and inorganic phases. Some elements are incorporated preferentially into organic phases, and others are incorporated into inorganic phases. Chemical sample pretreatment to remove the organic matrix prior to trace element analysis may increase the applicability of the investigated proxy relationship, though its efficiency and side effects remain questionable. We treated inorganic calcium carbonate and bivalve shell powder (Arctica islandica) with eight different chemical treatments including H 2 O 2 , NaOH, NaOCl, and acetone and analyzed the effects on (1) Me/Ca ratios (Sr/Ca, Mg/Ca, Ba/Ca, and Mn/Ca), (2) organic matter (≈N) content, and (3) mineralogical composition of the calcium carbonate. The different treatments (1) cause element and treatment specific changes of Me/Ca ratios, (2) vary in their efficiency to remove organic matter, and (3) can even alter the phase composition of the calcium carbonate (e.g., formation of Ca(OH) 2 during NaOH treatment). Among all examined treatments there were none without any side effects. In addition, certain Me/Ca changes we observed upon chemical treatment contradict our expectations that lattice-bound elements (Sr and Ba) should not be affected, whereas non-lattice-bound elements (Mg and Mn) should decrease upon removal of the organic matrix. For instance, we observe that NaOCl treatment did not alter Sr/Ca ratios but caused unexpected changes of the Mg/Ca ratios. The latter demonstrates that the buildup of complex biogenic composites like the shell of Arctica islandica are still poorly understood.

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Technische Biopolymere

Cited by 74 publications

References 6 publications

Water Repellence and Oxygen and Water Vapor Barrier of PVOH-Coated Substrates before and after Surface Esterification

Water Repellence and Oxygen and Water Vapor Barrier of PVOH-Coated Substrates before and after Surface Esterification

Improvement of Biodegradation of Wood Plastic Composites using Rice-Bran Mixture

Impact of sample pretreatment on the measured element concentrations in the bivalveArctica islandica

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