3 resultados para Thermally-modified wood

em Deakin Research Online - Australia


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The aim of this study was to investigate the effect of modification processes on physical properties and explain the mechanism of sustained drug release from modified rice (MR). Various types of Vietnamese rice were introduced in the study as the matrices of sustained release dosage form. Rice was thermally modified in water for a determined temperature at different times with a simple process. Then tablets containing MR and isradipine, the model drug, were prepared to investigate the capability of sustained drug release. Scanning electron microscopy (SEM) was used to determine different morphologies between MR formulations. Flow property of MR was analyzed by Hausner ratio and Carr's indices. The dissolution rate and swelling/erosion behaviors of tablets were evaluated at pH 1.2 and pH6.8 at 37±0.5°C. The matrix tablet containing MR showed a sustained release as compared to the control. The SEM analyses and swelling/erosion studies indicated that the morphology as well as swelling/erosion rate of MR were modulated by modification time, drying method and incubation. It was found that the modification process was crucial because it could highly affect the granule morphologies and hence, leading to the change of flowability and swelling/erosion capacity for sustained release of drug.

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Purpose – The results which that study seeks to report are the first part of a larger research programme funded by the New Zealand Foundation for Research, Science & Technology (FRST) aimed at gaining a better understanding of stakeholder perceptions in relation to bio-based products.

Design/methodology/approach – Utilising three chemically modified wood products, data were collected from focus groups and questionnaires and centred primarily on perceptions surrounding the acceptability of building materials that have been bio-modified. Irrespective of the type of chemical modification, family health and durability were the most important factors identified.

Findings – The study finds that product cost rated lower in the 16 factors evaluated, and energy used in production was of little concern. When comparing the three products to one another, two distinct groups with quite differing purchasing philosophies were identified and these perspectives significantly influenced perceptions of product acceptability and willingness to purchase. Utilising a paired comparison technique, an investigation of trade-offs indicated preference for performance over cost and product familiarity. Similarly, low chemical emissions were also preferred over cost considerations. Among the findings, there was scepticism regarding trust in manufacturers to adequately safeguard health and safety and to have a minimum impact on the environment. Low levels of trust were expressed in regard to manufacturers' concern for future generations.

Originality/value – The paper develops an investigative framework which could be applied to the evaluation of products arising from bio-material technology innovation and recommendations for future research directions.

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Blends between the widely used thermoset resin, epoxy, and the most abundant organic material, natural cellulose are demonstrated for the first time. The blending modification induced by charge transfer complexes using a room temperature ionic liquid, leads to the formation of thermally flexible thermoset materials. The blend materials containing low concentrations of cellulose were optically transparent which indicates the miscibility at these compositions. We observed the existence of intermolecular hydrogen bonding between epoxy and cellulose in the presence of the ionic liquid, leading to partial miscibility between these two polymers. The addition of cellulose improves the tensile mechanical properties of epoxy. This study reveals the use of ionic liquids as a compatible processing medium to prepare epoxy thermosets modified with natural polymers.