J.T.P. Derksen

Renewable resources in coatings technology: a review

In recent years an increasing interest is observed in the development of more environment friendly paints and coatings. This paper discusses advances in the use of renewable resources in formulations for various types of coatings. In particular, current research on the application of plant proteins and vegetable oils in coatings systems is addressed. In ongoing plant protein research at ATO-DLO corn, but particularly wheat gluten, was modified chemically to obtain aqueous protein dispersions that have excellent film-forming characteristics and strong adhesion to various surfaces. In particular, wheat gluten films have very interesting mechanical properties, such as an extensibility over 600%. Gas and moisture permeabilities were found to be easily adjustable by changing the exact formulation of the protein dispersion. Durability and water resistance of the coatings can be tailored by, for example, varying the degree of crosslinking of the protein binder. Based on the observed characteristics of the modified protein binders the development of novel, organic solvent-free paints and coatings appears to be well within reach. Regarding vegetable oil-based binders, research at ATO-DLO and elsewhere includes the application of oils from conventional as well as new oilseed crops. A very interesting new vegetable oil originates from such crops as Euphorbia lagascae and Vernonia galamensis, which have high contents (>60%) of an epoxy fatty acid (9c,12,13 epoxy-octadecenoic acid or vernolic acid) that can be used as a reactive diluent. Another interesting new oil is derived from Calendula officinalis, or ‘marigold’. This oil contains >63% of a Cl8 conjugated triene fatty acid (8t,lOt,l2c-octadecatrienoic acid or calendic acid) like that in tung oil. Current research is focused on the film-forming abilities of these oils and of chemical derivatives of these oils, in particular in emulsion systems.

Paints and coatings from renewable resources

Abstract In recent years an increasing interest is observed in the development of more environment-friendly paints and coatings. This paper discusses advances in the use of renewable resources in formulations for various types of coatings. In particular, recent developments in the application of (new) vegetable oils and plant proteins in coating systems are addressed. Regarding vegetable-oil-based binders, current research is focussed on an increased application of oils from conventional as well as new oilseed crops. A very interesting new vegetable oil, for example, originates from such crops as Euphorbia lagascae and Vernonia galamensis, which have high contents (>60%) of an epoxy fatty acid (9c,12,13 epoxy-octadecenoic acid or vernolic acid) that can be used as a reactive diluent. Another interesting new oil is derived from Calendula officinalis, or “Marigold”. This oil contains >63% of a C18 conjugated tri-ene fatty acid (8t,10t,12c-octadecatrienoic acid or calendic acid), analogous to the major fatty acid in tung oil. Presently, research aims at evaluating film-forming abilities of these oils and of chemical derivatives of these oils, both in solvent-borne and water-based emulsion systems. In research on industrial applications of plant proteins, corn, but particularly wheat gluten has been modified chemically to obtain protein dispersions that have excellent film-forming characteristics and strong adhesion to various surfaces. Especially wheat gluten films have very interesting mechanical properties, such as an extensibility of over 600%. Gas and moisture permeabilities were found to be easily adjustable by changing the exact formulation of the protein dispersion. Durability and water-resistance of the coatings can be tailored by e.g., varying the degree of cross-linking of the protein binder.

New seed oils for oleochemical industry: evaluation and enzyme-bioreactor mediated processing

Abstract The introduction of new oilseed crops for the production of vegetable oils for oleochemical uses is currently under investigation. Crops like Crambe abyssinica, Limnanthes alba, Dimorphotheca pluvialis and Euphorbia lagascae contain oils with high proportions of industrially interesting, and sometimes unusual fatty acids, such as erucic or other very long-chain fatty acids, hydroxy fatty acids or epoxy fatty acids. In this paper we present an overview of our investigation of aspects of the processing of the new oilseeds and their oils. The optimal oil quality and content from the new seeds was studied with respect to sowing date and harvest time. Oil from the harvested seeds was recovered with both mechanical expelling and solvent extraction techniques. It was found that for Euphorbia and Crambe seeds cold-pressing resulted in acceptable oil yields and qualities. Cold-pressing was found to be unsatisfactory for oil recovery from Dimorphotheca and Limnanthes seeds. For the latter, optimal conditions for solvent extraction are presently explored. The recovered oils were subjected to enzymatic hydrolysis to isolate the fatty acids of interest. We were particularly successful in isolating the highly reactive hydroxy and epoxy fatty acids. This is especially relevant since these fatty acids can be isolated by conventional chemical techniques only with great difficulty, due to their thermal instability. When 1,3-positional specific lipases were employed, erucic acid could be recovered at high purity from the highly symmetric Crambe oil triglycerides, thus facilitating the down-stream processing of the erucic acid. New developments in membrane technology lead to highly efficient enzyme supports to permit a continuous enzymatic oil hydrolysis.

Extraction and characterization ofDimorphotheca pluvialis seed oil

Dimorphotheca pluvialis is increasingly recognized as an interesting industrial new oilseed crop because it contains up to 60% of the unusual fatty acid dimorphecolic acid (9-hydroxy,10t,12t-18∶2) (DA) for which new applications are being developed. In this paper, the yield, composition and quality are evaluated for dimorphotheca oils (DMO) which were recovered by pressing, conventional solvent extraction and supercritical carbon dioxide extraction (SCE). Mechanical pressing of the seeds required high temperatures and resulted in an oil recovery of only 40%, whereas the extraction protocols yielded more than 95%. Oil recovery by pressing of winged seed was even more difficult than that of unwinged seeds; hence, solvent extraction of winged seeds was preferred. The dark-colored DMO, recovered by expelling or by extraction with organic solvents, needed further refining to remove pigments and gums, whereas the light yellow-colored SCE DMO did not require further refining. SCE oil had a low phospholipid content (11 mg P/kg). Pressed oil (95 mg P/kg) and hexaneor pentane-extracted DMO (200 mgP/kg) had much higher phospholipid contents. Peroxide andp-anisidine values were low for freshly recovered oils, but increased after storage, especially in the SCE oil, due to the low concentration of natural antioxidants in SCE DMO, such as tocopherols. The DA content of the oils recovered by the various techniques showed only minor differences, except that supercritical carbon dioxide had slightly decreased solubilizing power for tri- and di-dimorphecolin as compared to hexane and pentane.

The processing of new oilseed crops -an economic evaluation

The economics of pilot- to large-scale processing of the new oilssed cropsCrambe abyssinica, Euphorbia lagascae, andDimorphotheca pluvialis into oil, fatty acids, or esters were estimated. It was found that the processing costs forCrambe seed to oil is in the same range as that for rapeseed (≈0.5 U.S.

Enzymatic peroxycarboxylic acid formation in a hollow-fibre membrane reactor: kinetics and mass transfer

/kg). Production of fatty acid esters from vernolic and dimorphecolic acids requires some special downstream processing operations that result in processing costs of about 1 U.S.

Lipases Used for the Production of Peroxycarboxylic Acids

/kg ester. Good-qualityDimorphotheca oil is much more difficult to obtain and requires supercritical carbon dioxide extraction. Processing costs can be as high as 4 U.S.

Supercritical carbon dioxide extraction ofDimorphotheca pluvialis oil seeds

/kg oil.

Lipase-catalyzed hydrolysis of Crambe oil in AOT-isooctane reversed micelles

Abstract Peroxycarboxylic acids were produced enzymatically in a hollow-fibre membrane reactor, using R. javanicus and C. antarctica lipase as the biocatalysts. The peroxycarboxylic acids are commercially used to synthesize epoxides from unsaturated olefins. Here, oleic acid was converted to 9,10-epoxy stearic acid. A mass-transfer model, similar to heterogeneous catalysis was applied to the enzymatic reaction in a membrane reactor. The model enables the evaluation of the most important factors limiting the conversion rate in the reactor and the effect of the membrane material on mass transfer. It was found that the conversion is diffusion limited at a high concentration of the organic substrate. To illustrate the versatility of the model, it was applied to two situations performed under completely different circumstances.

Activity of immobilized lipoxygenase used for the formation of perhydroxyacids

Stabilization of Upases by immobilization on different polymer materials has been shown. The Upases were used for triglyceride hydrolysis and the synthesis of the chemically very reactive peroxycarboxylic acids. Using in-situ produced peracids, epoxides were formed from oleic acid. Inactivation of the enzymes is probably due the substrate hydrogen peroxide.