In order to clarify the chemical color change of teak (Tectona grandis L.F.), the difference of chemical composition between the heartwood and sapwood of teak was investigated by gas chromatography–mass spectrometry (GC-MS) based on the acetone extractive compounds. The results showed that the difference in content of the main components between heartwood and sapwood was not obvious. However, the amount of extractives in heartwood was higher than that in sapwood, especially for phenols, quinones, and ketones. The most obvious different substances in the acetone extractive between heartwood and sapwood were 4-tert-butyl-2-phenyl-phenol,2-methyl-anthraquinone, and 2,3-dimethyl-1,4,4a,9a-tetrahydro-9,10-anthracenedione, which might be the main composition for the chromatic aberration of teak. This paper focuses on a preliminary study and further work such as high-performance liquid chromatography (HPLC) with ultraviolet photometric detector (UV)/mass spectrometry (MS) will be carried out.

A kind of novel sustainable mycelium/cotton stalk composite were prepared in laboratory by growing white rot fungus of Ganoderma lucidum on cotton stalk and stored in a block mold followed by hot-pressing process. To improve the mechanical properties, the composites were, respectively, subject to water immersion prior to hot-pressing at various water uptake (20%, 30%, 40% and 50%). The mechanical properties including flexural and internal bonding properties were tested. The results showed that with increasing water uptake, the mechanical properties of the composites increased at first after reaching the maximum at water uptake of 30 wt% in accordance with the saturation point of cotton stalk. Therefore, the water contributed to the good interface between mycelium and cotton stalk particles, where the flexural and internal bonding strength met the standard for non-load bearing particleboard listed in ANSI A208.1–2016. However, at water uptake higher than 30 wt%, no further improvement occurred due to the excessive water located in cell lumen rather than in the cell wall.

A fast water-based ultraviolet light (UV) curing polyurethane-acrylate (PUA) wood coating was prepared in the laboratory, and applied on oak (Quercus alba L.) at different coating amounts. The PUA wood coating can be fast cured within 22 min, which highly improved the drying speed compared to normal water-based wood coatings (often higher than 35 min). The coating amounts affected the coating properties after curing on oak. With the increase of coating amount, the adhesion, hardness and gloss value of surface increased to different extents. Meanwhile, the surface of sample became smooth gradually because the voids of the oak were filled. Thus, higher coating amount resulted in better coating properties. However, no significant increase of penetration depth was found. During curing, the hydroxyl groups of the wood reacted with the coating. The optimal parameter in this study was the coating amount of 120 g/m², where the adhesion reached 1 (with 0–5% cross-cut area of flaking along the edges), with the hardness of 2H and the gloss of 92.56°, which met the requirement of Chinese standard GB/T 18103–2013, and could be used for engineered wood flooring.

For this paper, two kinds of waterborne coatings, polyurethane acrylate (PUA) and epoxy resin, were synthesized and then coated onto neat bamboo and bamboo scrimber (BS), respectively. The coating performance of the samples was investigated. The results showed that, for the two kinds of coatings, there was a chemical reaction occurring between both coatings and the substrates. The permeability with respect to bamboo was higher than that of BS, while that of the epoxy resin coating was better than PUA. However, the PUA film was smoother than epoxy resin. The epoxy resin coating on bamboo had the best adhesion, which was at a 1 level. The abrasion values of the four samples varied in the same substrate. A higher hardness of the coating film was obtained when coated with PUA. In general, the coating performance of bamboo scrimber was poorer than that of bamboo, either coated with PUA or epoxy resin. The epoxy resin had a better coating performance than PUA.

In this paper, a kind of high solid content water-based polyurethane-acrylate (PUA) coating was synthesized in laboratory. Bamboo, bamboo scrimber, and heat-treated bamboo scrimber were selected as substrates and coated with the PUA coating. The coating properties of those materials were investigated. The results showed that PUA coating could well cover the surface of the three kinds of materials. However, the coating performances varied among these substrates due to their different chemical and morphological surfaces. Due to the densified structures, small pores, and improved hydrophobicity of bamboo scrimber, it was difficult for PUA coating to wet and penetrate into the substrate, where the smaller contact angle and penetration depth were obtained compared with bamboo. In contrast, heat-treated one had better hydrophilicity and smaller contact angle with PUA coating than pure bamboo scrimber. Therefore, the coating performance of heat-treated bamboo scrimber was better with lower average roughness value. However, the adhesion classification between the coating and all substrates was 2 (with 5-15% cross-cut area of flaking along the edges).