Performance of polyurethane coatings on acetylated and benzoylated rubberwood

Pandey, Krishna K.; Srinivas, Kavyashree

doi:10.1007/s00107-014-0860-2

Cited by 19 publications

(8 citation statements)

References 29 publications

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“…Acetylation of rubber wood for 8 h and 48 h resulted in an average WPG of around 7% and 10%. The WPG obtained in this study is at the lower limit of what has been reported in previous studies (Pandey andPitman 2002, Pandey andSrinivas 2015;Rafidah et al 2006). In those studies temperatures of 100°C and above were used, whereas modification was performed at 70°C in the present study.…”

Section: Weight Gain Of Acetylated Rubber Woodsupporting

confidence: 46%

“…It is not known, if the presence of tension wood alters the influence of acetylation and weathering on the mechanical properties of rubber wood. Rubber wood has previously been acetylated with different WPGs, depending on treatment temperature and reaction times (Chauhan et al 2001;Pandey and Pitman 2002;Pandey and Srinivas 2015;Rafidah et al 2006). Many of these studies report on using high temperature and long treatment times to achieve high WPGs.…”

Section: Introductionmentioning

confidence: 99%

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Mechanical behaviour of acetylated rubber wood subjected to artificial weathering

et al. 2019

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Rubber wood utilization in Nigeria has become a viable alternative because of over-exploitation of more durable species. The use of rubber wood in its native form has some disadvantages including dimensional instability, low durability and susceptibility to weathering in outdoor uses. However, it may be improved through chemical modification such as acetylation. In this study, we revealed the effectiveness of acetylation on the protection of rubber wood against weathering in terms of weight loss (WL), colour change, lignin degradation, and mechanical properties. Acetylation was carried out using two different reaction times to achieve weight percent gains (WPG) of around 7% and 10%. Understanding of the effect of acetylation and subsequent weathering on mechanical properties was enabled by analysing wood chemistry with Fourier transform infrared (FTIR) analysis and Raman spectroscopy. The mechanical tests of weathered unmodified and acetylated rubber wood revealed a decrease of tensile stiffness of the unmodified samples as a function of weathering time, while stiffness was retained for the acetylated samples. Weathered unmodified samples showed a bi-phasic stress-strain pattern with a high strain at breakage indicating a slippage of fibres under stress due to degradation of the middle lamella. This was hardly visible for acetylated samples. Thus, acetylation was shown to be effective for protecting rubber wood used in outdoor conditions.

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Section: Weight Gain Of Acetylated Rubber Woodsupporting

confidence: 46%

Section: Introductionmentioning

confidence: 99%

Mechanical behaviour of acetylated rubber wood subjected to artificial weathering

et al. 2019

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“…Because of these disappointing findings, the California Redwood Association stopped recommending clear finishes for redwood used outdoors. Subsequent testing in several countries have confirmed the poor performance of clear coatings on wood exposed outdoors-most fail within 2 years in temperate climates, and failure within a year is common in tropical climates [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

“…Hence, the most obvious way to improve the performance of clear coatings on wood is to photostabilize the wood surface before applying clear coats. Numerous studies using a variety of photostabilizers have confirmed the veracity of such an approach [11,12,15,[17][18][19]. Indeed, the best photoprotective systems can easily double the lifetime of clear coatings on wood, but such an increase falls short of what is needed.…”

Section: Introductionmentioning

confidence: 99%

Improving the Performance of Clear Coatings on Wood through the Aggregation of Marginal Gains

et al. 2016

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Remarkable increases in the performance of complex systems can be achieved by a collective approach to optimizing individual factors that influence performance. This approach, termed the aggregation of marginal gains, is tested here as a means of improving the performance of exterior clear-coatings. We focused on five factors that influence clear-coating performance: dimensional stability of wood; photostability of the wood surface; moisture ingress via end-grain; coating flexibility and photostability; and finally coating thickness. We performed preliminary research to select effective wood pre-treatments and durable clear-coatings, and then tested coating systems with good solutions to each of the aforementioned issues (factors). Red oak and radiata pine panels were modified with PF-resin, end-sealed, and thick acrylic, alkyd or spar varnishes were applied to the panels. Panels were exposed to the weather and the level of coating defects was assessed every year over a 4-year period. All of the coatings are performing well on PF-modified pine after 4 years' outdoor exposure. In contrast, coatings failed after 2 years on unmodified pine and they are failing on PF-modified oak. We conclude that our approach shows promise. Future research will build on the current work by developing solutions to additional factors that influence clear-coating performance.

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“…Resistance to impact is one of these test methods. It is used for determining the damages caused by the impacts during the use of impact test with various application methods, it is important to determine the best method (Nejad et al 2013, Kaygin and Akgun 2008, Keskin and Tekin 2011, Pandey and Sirinivas 2015. Impact tests evaluate the effects of accidental contact damage that may occur in the place of use.…”

Section: Introductionmentioning

confidence: 99%

Layer thickness performances of coatings on MDF: Polyurethane and cellulosic paints

Erdinler

Koç

Dilik

et al. 2019

Maderas, Cienc. tecnol.

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Furniture from wood material is exposed to various external effects. Impact has negative influence on these materials. Surface treatment is effective on wood material's durability. This may change due to layers of paint and the property of the paint used on the material. The aim of this study is to determine the differences by investigating the deformations occurring on Medium Density Fiberboard (MDF) with various surface treatments due to impact. Determination of the deformation values were performed by pendulum hardness test and rapid deformation test on MDF using polyurethane and cellulosic paints with different number of application layers. Impact tester was used for determining the effect of rapidly deforming sudden impacts. Pendulum hardness tester was used to determine the layer hardness of the surfaces. Statistical assessment was performed for determining and revealing the impacts. As result of the study, paint type, layer thickness and the interaction between them were significant. Highest layer hardness values for cellulosic paint application type 1 and polyurethane paint type 2 were 241,667 s and 222,133 s respectively. According to rapid deformation test it was determined that polyurethane paint application had better results than cellulosic paint application.

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Performance of polyurethane coatings on acetylated and benzoylated rubberwood

Cited by 19 publications

References 29 publications

Mechanical behaviour of acetylated rubber wood subjected to artificial weathering

Mechanical behaviour of acetylated rubber wood subjected to artificial weathering

Improving the Performance of Clear Coatings on Wood through the Aggregation of Marginal Gains

Layer thickness performances of coatings on MDF: Polyurethane and cellulosic paints

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