Colloidal lignin particles for weathering protection in wood coatings

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.advisor Leskinen, Timo Smyth, Matt 2017-10-30T07:51:57Z 2017-10-30T07:51:57Z 2017-10-03
dc.description.abstract Earth’s changing climate and the better understanding of harmful impacts caused by humans has increased the demand for more sustainable products. Lignin is a material that offers renewability, is safe for humans and the environment and is already a by-product of industry. This work uses a recently developed technique for preparing colloidal lignin particles (CLPs) and deploying them into water based industrial wood stain as a UV protectant. The initially transparent stains with added CLPs took on the dark brown color of lignin, with concentration of CLPs having only minor effect. The dispersions remained stable after CLP addition however, viscosity was drastically decreased with a strong correlation with CLP concentration. Siberian larch and spruce wood were coated with the standard commercial stains and stains with 1:1, 1:1.5, and 1:2 ratios of commercial UV absorber to CLP concentrations. Coated wood samples were then exposed to simulated sunlight for 92 hours. Changes in color and UV reflectance spectra were recorded, as well as periodic photographs during exposure. The CLP coated samples go through a more drastic magnitude of color change compared to uncoated (NAT) and standard (STD) samples, however the change in relation to initial color is much less. Additionally, the color after 92 hours of exposure is much closer to the initial color in CLP samples due to an almost cyclical change. Reflectance spectroscopy revealed further differences between CLP samples and both the STD and NAT samples. CLP samples showed a large decrease in absorption in the UVA region but little change in the UVB region. NAT samples showed a similar decrease in the UVA region but with a shifted peak, but also had strong decreases in absorption in the UVB region. The STD samples experienced a more uniform decrease in absorption, with some regions having higher and others lower changes in absorption compared to CLP samples. The overall effectiveness of CLPs remains somewhat uncertain due to the inability to remove the coatings from the wood beneath and see the color. This work did reveal however, some positive outcomes that indicate CLPs could be used effectively in industrial wood coatings. There were strong differences in the color and absorption changes between CLP samples and the NAT and STD samples. This indicates that the CLPs were changing instead of the wood beneath. Although the extent of protection is still uncertain, it can be concluded here that CLPs have potential for use as UV protectants in wood coatings. en
dc.format.extent 49 + 5
dc.format.mimetype application/pdf en
dc.language.iso en en
dc.title Colloidal lignin particles for weathering protection in wood coatings en
dc.type G2 Pro gradu, diplomityö fi Kemian tekniikan korkeakoulu fi
dc.subject.keyword lignin en
dc.subject.keyword wood coatings en
dc.subject.keyword wood weathering en
dc.subject.keyword colloidal particles en
dc.identifier.urn URN:NBN:fi:aalto-201710307280
dc.programme.major Fibre and Polymer Engineering fi
dc.programme.mcode CHEM3024 fi
dc.type.ontasot Master's thesis en
dc.type.ontasot Diplomityö fi
dc.contributor.supervisor Österberg, Monika
dc.programme Master's Programme in Chemical, Biochemical and Materials Engineering fi
dc.ethesisid Aalto 9626
dc.location P1 fi

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