https://espace.library.uq.edu.au/view/UQ:08f48a6/UQ08f48a6_OA.pdf

Degradation and stabilization of polyurethane elastomers

Plant extracts have been long used by the traditional healers for providing health benefits and are nowadays suitable ingredient for the production of formulated health products and nutraceuticals. Traditional methods of extraction such as maceration, percolation, digestion, and preparation of decoctions and infusions are now been replaced by advanced extraction methods for increased extraction efficiency and selectivity of bioactive compounds to meet up the increasing market demand. Advanced techniques use different ways for extraction such as microwaves, ultrasound waves, supercritical fluids, enzymes, pressurized liquids, electric field, etc. These innovative extraction techniques, afford final extracts selectively rich in compounds of interest without formation of artifacts, and are often simple, fast, environment friendly and fully automated compared to existing extraction method. The present review is focused on the recent trends on the extraction of different bioactive chemical constituents depending on the nature of sample matrices and their chemical classes including anthocyanins, flavonoids, polyphenols, alkaloids, oils, etc. In addition, we review the strategies for designing extraction, selection of most suitable extraction methods, and trends of extraction methods for botanicals. Recent progress on the research based on these advanced methods of extractions and their industrial importance are also discussed in detail.

/pdf/a-critical-analysis-of-extraction-techniques-used-for-a6s9jnpt60.pdf

A critical analysis of extraction techniques used for botanicals: Trends, priorities, industrial uses and optimization strategies

Stretchable electronics are mechanically compatible with a variety of objects, especially with the soft curvilinear contours of the human body, enabling human-friendly electronics applications that could not be achieved with conventional rigid electronics. Therefore, extensive research effort has been devoted to the development of stretchable electronics, from research on materials and unit device, to fully integrated systems. In particular, material-processing technologies that encompass the synthesis, assembly, and patterning of intrinsically stretchable electronic materials have been actively investigated and have provided many notable breakthroughs for the advancement of stretchable electronics. Here, the latest studies of such material-based approaches are reviewed, mainly focusing on intrinsically stretchable electronic nanocomposites that generally consist of conducting/semiconducting filler materials inside or on elastomer backbone matrices. Various approaches for fabricating these intrinsically stretchable electronic materials are presented, including the blending of electronic fillers into elastomer matrices, the formation of bi-layered heterogeneous electronic-layer and elastomer support-layer structures, and modifications to polymeric molecular structures in order to impart stretchability. Detailed descriptions of the various conducting/semiconducting composites prepared by each method are provided, along with their electrical/mechanical properties and examples of device applications. To conclude, a brief future outlook is presented.

Material-Based Approaches for the Fabrication of Stretchable Electronics.

Plastic biodegradation: Frontline microbes and their enzymes

Eugenol, a phytogenic bioactive component is frequently found in diversified herbal plants possessing well-defined functional attributes. Prominent sources of eugenol are clove, cinnamon, tulsi and pepper. Various extraction methods have been practiced globally for the extraction of eugenol and other nutraceutics from plants. The most extensively employed approaches in this regard include solvent extraction, hydro-distillation, microwave-assisted extraction, supercritical carbon dioxide extraction and ultrasound-based extraction. Eugenol has been approved to encompass numerous beneficial aspects against a capacious spectrum of life threatening indispositions including oxidative stress, inflammation, hyperglycemia, elevated cholesterol level, neural disorders and cancer. In addition, eugenol has also shown strong potential as an antimicrobial agent against wide ranges of pathogenic and spoilage causing microorganisms. Predominantly, the principle mechanistic approaches associated with the therapeutic potential of eugenol include its free radical scavenging activity, hindrance of reactive oxygen species' generation, preventing the production of reactive nitrogen species, enhancement of cyto-antioxidant potential and disruption of microbial DNA & proteins. Consequently, this article is an attempt to elucidate the general properties, sources, extraction methods, therapeutic role and associated mechanisms of eugenol.

/pdf/essential-oil-eugenol-sources-extraction-techniques-and-2w5qrj34yw.pdf

Essential oil eugenol: sources, extraction techniques and nutraceutical perspectives

Polyurethanes (PUs) are a class of versatile materials with great potential for use in different applications, especially based on their structure–property relationships. Their specific mechanical, physical, biological, and chemical properties are attracting significant research attention to tailoring PUs for use in different applications. Enhancement of the properties and performance of PU-based materials may be achieved through changes to the production process or the raw materials used in their fabrication or via the use of advanced characterization techniques. Clearly, modification of the raw materials and production process through proper methods can produce PUs that are suitable for varied specific applications. The present study aims to shed light on the chemistry, types, and synthesis of different kinds of PUs. Some of the important research studies relating to PUs, including their synthesis method, characterization techniques, and research findings, are comprehensively discussed. Herein, recent advances in new types of PUs and their synthesis for various applications are also presented. Furthermore, information is provided on the environmental friendliness of the PUs, with a specific emphasis on their recyclability and recoverability.

https://ir.unikl.edu.my/jspui/bitstream/123456789/15237/1/Polyurethane%20types%2c%20synthesis%20and%20applications%20%e2%80%93%20a%20review.pdf

Polyurethane types, synthesis and applications – a review

Essential oil from Cinnamomum cassia bark through hydrodistillation and advanced microwave assisted hydrodistillation

The study investigated the suitability of waste rubber powder (WRP) use as filler in adhesive formulation for plywood application. Melamine Urea Formaldehyde (MUF) was employed as resin for formulating the wood adhesive. To improve chemical properties and bonding quality of adhesive, WRP was treated by different chemicals like 20% nitric acid, 30% hydrogen peroxide and acetone solution. The treated WRP were analysed by XRD and it showed that inorganic compounds were removed and carbon was remained as major component under the treatment of 20% HNO3. The treatment improved the mechanical properties like shear strength and formaldehyde emission of plywood (high shear strength and low formaldehyde emission). The physico-chemical interaction between the wood, resin and filler was investigated using fourier transform infrared spectroscopic (FTIR) technique and the interactions among N-H of MUF and C=O of wood and WRP were identified. The morphology of wood-adhesive interface was studied by field emission scanning electron microscope (FESEM) and light microscope (LM). It showed that the penetration of adhesives and fillers through the wood pores was responsible for mechanical interlocking. Therefore, chemically treated WRP proved its potential use as filler in MUF based adhesive for making plywood.

https://www.sciendo.com/pdf/10.1515/pjct-2015-0007

Effect of waste rubber powder as filler for plywood application

Demand for hydroxyapatite (HA) is increasing annually, due to the growing number of orthopedic patients. Therefore, there is a challenge of meeting this growing demand without interfering with the integrity of the environment. The aim of this study is to produce HA from natural sources. In this study, natural HA was extracted from cow bone through ultrasound treatment of the raw bone followed by calcination at different temperatures from 650-950 oC [1, 2]. Ultrasound treatment in ordinary water medium is found to be suitable for cleaning the bone and the HA produced after calcination at 950 oC was found to possess the desirable properties needed for pure HA.

Nitthiyah Jeyaratnam

Papers

Polyurethane types, synthesis and applications – a review

Essential oil from Cinnamomum cassia bark through hydrodistillation and advanced microwave assisted hydrodistillation

Effect of waste rubber powder as filler for plywood application

Characterization and Elemental Quantification of Natural Hydroxyapatite Produced from Cow Bone

Effect of Jatropha Seed Oil Meal and Rubber Seed Oil Meal as Melamine Urea Formaldehyde Adhesive Extender on the Bonding Strength of Plywood