Development of surface coating materials of wax esters and epoxides for coating industries
There has been an increasing interest and strong demand for fine quality coating materials that can be applied to various substrates. Coating materials contained high proportion of acrylate based products which affect human health related toxicity, primarily on carcinogenicity. Researchers make effo...
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| Format: | Thesis |
| Language: | English |
| Published: |
2012
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/66292/1/FS%202012%20104%20IR.pdf |
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| Summary: | There has been an increasing interest and strong demand for fine quality coating materials that can be applied to various substrates. Coating materials contained high proportion of acrylate based products which affect human health related toxicity, primarily on carcinogenicity. Researchers make efforts to eliminate this substrate by replacing with other materials such as wax esters and epoxides from renewable raw materials especially oil crops. A major problem with this kind of application is, coating characteristics features are very low, thus ingredient of coating formulation was developed to improve coating characteristics.
In this research, two different model reactions and an end application of coating formulation were studied. Firstly, esters were produced as reactive diluents in coating component through enzymatic esterification of fatty acids, and secondly, chemo-enzymatic epoxidations were carried out to produce epoxidized fatty acids. Finally, both products were formulated to be used in coating formulation.
Enzymatic syntheses of esters from oleochemicals and petrochemicals were studied using Novozyme 435 as biocatalyst. Immobilized enzyme was utilized due to their considerable advantages over enzymes in bulk solution such as high thermal and operational stability as well as easy recovery. Results showed that Novozyme 435 is a good biocatalyst in esterification of esters with high percentage of yield of more than 95.0%. The optimum conditions for esterification of adipate esters were 30 minutes incubation period, while it was carried out at 50°C, and hexane as a solvent.
Chemo-enzymatic epoxidation of fatty acids which are oleic acid, linoleic acid and ricinoleic acid was also catalyzed by Novozyme 435 and hydrogen peroxide; in a solvent-free medium. Immobilized enzyme was used to catalyze the formation of peracid from fatty acid, meanwhile hydrogen peroxide was utilized for the epoxidation of the vinyl group of fatty acids to form the desired epoxide. Synthesis of epoxidized oleyl oleate by oleic acid and oleyl alcohol gave 3.7 oxirane number and 94% yield. Reaction of linoleic acid and oleyl alcohol produced 92% of epoxidized linoleyl oleate with 2.7 iii oxirane number. Yield (89%) of epoxidized ricinoleyl oleate was produced by the reaction of ricinoleic acid and oleyl alcohol with 1.8 oxirane number.
Wax esters and epoxides were applied as surface coating formulation containing adipate esters, fatty acid epoxides, epoxy acrylate, Brij 30, PETIA and photoinitiator and dried by UV radiation curing. Coated film from this formulation gave good performance during Soxhlet extraction and hardness test. In this study, gel content exhibited more than 90.0% polymerization, while the pendulum hardness gave 55.3% of hardness. Both analyses were significant to determine the effect of irradiation passes. Scratch test was carried out to verify the resistant of coating. The highest weight loaded can be resisted by the wax esters formulation was 4.5 N.
In order to produce high quality coating formulation, screening of compositions of epoxy acrylate was done to reduce the toxicity percentage. Samples were formulated containing epoxy acrylates and epoxides from epoxidized soybean oil (ESBO) and fatty esters. Both formulations were used to improvise the properties of coating by replacing acrylate with epoxides and wax esters. In evaluation of coating performance, epoxy acrylate was reduced until 75% composition with high quality coatings formulation (Formulation 23-24). |
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