Wettability and surface roughness of thermally modified plywood panels

The objective of this research was to investigate the wettability and surface roughness properties of the plywood panels under thermal modification. The plywood panel specimens were subjected to thermal modification under atmospheric pressure and presence of air at a temperature of 150, 170 or 190 °C for 60 min. The contact angle measurements were obtained by using a KSV Cam-101 Scientific Instrument connected with a digital camera and computer system. The roughness measurements, average roughness (R_a) and maximum roughness (R_max), were performed based on both parallel and perpendicular to the grain using a fine stylus tracing technique. Statistical analyses showed significant differences in the surface roughness and contact angle values of the plywood panels following thermal modification.     

Effect of particle size,shape and surface roughness on bulk and shear properties of rice flour

The present study was conducted to compare the flowability of basmati and non-basmati rice flour with commercially available rice flour. Dynamic and shear properties were characterized on the basis of particle size, shape and surface roughness (measured by Atomic Force Microscope) depending upon the processing conditions. In contrast to commercial rice flour having less particle size (65.3 μm), the particle sizes (171.1–171.9 μm) of both the samples were not significantly different. However, the flowability of the non-basmati rice flour was significantly affected by its particle shape (0.487), surface roughness (124.23 nm) and compressibility (25.32%), making it more cohesive than basmati rice flour but less cohesive than commercial rice flour (1.34 kPa). Also, basic flow energy was significantly higher in both commercial rice flour and non-basmati flour, thus required more energy (197.42 mJ and 147.54 mJ, respectively) to flow than basmati rice flour (130.15 mJ). Overall, flowability was analysed by applying three different pressures (3, 6 and 9 kPa) and among which commercial rice flour was found less flowable (2.26 at 9 kPa) followed by non-basmati rice flour (2.33 at 9 kPa) and basmati (3.35 at 9 kPa) causing bulk handling difficult.     

Synthesis of rosinimide modified with polyphenylpyridinylsiloxane and its characteristics

Rosin maleic anhydride adduct (RMA)-bisester was prepared by the esterification of chlorinated RMA with hydroquinone. Phenylpyridinylcyclotrisiloxane (D ₃ ^Ph,Py ) was synthesized from phenylpyridinyldichlorosilane in the presence of zinc oxide catalyst, and amino group terminated polyphenylpyridinylsiloxane prepolymer was prepared by equilibrium polymerization of D ₃ ^Ph,Py with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane. Rosinimide (PSMR) was prepared from the imidization of RMA-bisester with polyphenylpyridinylsiloxane prepolymer at 120°C for 7 h using γ-butyrolactone/pyridine. It showed that PSMR had better thermal stalbility than rosinimide modified with polydimethylsiloxane.     

Investigation of surface properties of physico-chemically modified natural fibres using inverse gas chromatography

Inverse gas chromatography (IGC) is a suitable method to determine surface energy of natural fibres when compared to wetting techniques. In the present study, the surface properties of raw and modified lignocellulosic fibres have been investigated by IGC. The fibres chosen for the study were flax, hemp, kenaf, agave, agave hybrid, sisal and pineapple. The treatments used were 4% NaOH and 2% zein. The uniqueness of zein treatment is that it is bio-based and therefore maintains the biodegradable character of the natural fibres. Fourier transform infrared spectroscopy (FTIR) and environmental scanning electron microscope (ESEM) were also performed to characterize the surface changes in fibres. The surface properties of fibres are influenced by the chemical composition, crystallinity and morphology of the fibres. Bast fibres exhibited higher surface dispersive energy than leaf fibres. The raw fibres have a predominant basic character, whereas the alkaline treatment makes the fibres more acidic. Both alkaline and zein treatments decrease the dispersive surface energy and the specific free energy of adsorption.     

Effect of enzyme treatment and wood pulp variation on physical characteristics and fabric hand of lyocell fabrics

The purpose of the research was to examine the effect of three different levels of enzyme treatment on the physical characteristics and the end-use suitability of the lyocell fabrics made with four different types of commercial wood pulp. The appropriate enzyme concentration for obtaining an optimum as well as consistent physical characteristics and fabric hand trait was 3 g/l for the concentration levels tested in the present investigation. Weight loss was more affected by higher enzyme concentration than other physical properties. H2 was least affected by enzyme treatment for all three physical properties and fabric hand. 5 g/l concentration exhibited little difference from 3 g/l in the physical characteristics, whereas the KES-FB values indicated a significant loss of fabric hand in most PHVs with the 5 g/l concentration level. Among different garment parameters, all four fabric types were relatively inappropriate for the men’s slacks (MS) fabric due to the lower hand value of koshi required by the MS parameter. However, despite the relatively low koshi values, high fukurami values required for men’s dress shirt (MWDS) resulted in the highest THV among the four garment parmeters. The four fabric types, which represent the usage of four different wood pulps, in general seem to exhibit a higher applicability to women’s winter thin dress (WWTD) than women’s winter suit (WWS) garment parameter.     

Surface treatments of jute fabric: The influence of surface characteristics on jute fabrics and mechanical properties of jute/polyester composites

In this study, jute fabrics were modified by alkali, micro-emulsion silicon (MS) and fluorocarbon based agents (FA) in order to enhance the interfacial adhesion between the polyester matrix and the jute fiber. X-ray photoelectron spectroscopy (XPS) and contact angle measurements were used to characterize fiber surfaces. The effects of various surface treatments on the mechanical and morphological of jute/polyester composites were also studied. All surface treatments were shown to improve the tensile, flexural strengths and interlaminar shear strengths of the composites. Moreover, the maximum improvement in the mechanical properties was obtained for the FA treated jute/polyester composites. SEM micrographs of the tensile fracture surface of jute/unsaturated polyester composites also exhibited improvement of interfacial and interlaminar shear strengths by the alkali, MS and FA treatments of jute fibers.     

Analysis of urbanization characteristics causing farmland loss in a rapid growth area using GIS and RS

This study aims to analyze the spatial characteristics of urbanization in a rapid growth area. Remote sensing (RS) and geographic information system (GIS) techniques were used to classify land uses in 1986 and 1996, the most rapid growth period. The two land-use maps were classified with accuracies of 90% and 86% in verification areas for 1986 and 1996, respectively, by a supervised maximum likelihood method. Urbanization in the greenbelt within the study area was restricted, while outside the greenbelt it occurred rapidly. Fifty seven percent of the total increase in built-up area in the study area was concentrated in a 10-km GIS-defined buffer zone adjacent to the greenbelt. The priority for new residential development was put on areas with slopes of less than 15 degrees and potential farmland in the areas surrounding Seoul. In the priority area, farmland loss was very significant. These results show that although the environmental protection of ecologically valuable land was well enforced by the greenbelt from urbanization, farmland was not conserved in comparison to new residential development in the rapid growth area.