Polymer science and technology

Advanced Structured Materials, 2013

Bacterial cellulose (BC) has established to be a remarkably versatile biomaterial and can be used in wide variety of applied scientific endeavours, especially for medical devices. In fact, biomedical devices recently have gained a significant amount of attention because of an increased interest in tissue-engineered products for both wound care and the regeneration of damaged or diseased organs. Due to its unique nanostructure and properties, microbial cellulose is a natural candidate for numerous medical and tissue-engineered applications. Hydrophilic bacterial cellulose fibers of an average diameter of 50 nm are produced by the bacterium Acetobacter xylinum, using a fermentation process. The microbial cellulose fiber has a high degree of crystallinity. Using direct nanomechanical measurement, determined that these fibers are very strong and when used in combination with other biocompatible materials, produce nanocomposites particularly suitable for use in human and veterinary medicine. Moreover, the nanostructure and morphological similarities with collagen make BC attractive for cell immobilization and

The time has come," the Walrus said, "To talk of many things: Of shoes--and ships--and sealing-wax--Of cabbages--and kings--" Lewis Carroll, Through the Looking Glass shoes, ship, sealing wax, cabbage, and a king

T he clothes which we wear are made of fabrics. Fabrics are made from fibres obtained from natural or artificial sources. Can you name some natural fibres? Fibres are also used for making a large variety of household articles. Make a list of some common articles made from fibres. Try to separate them into those made from natural fibres and those made from artificial fibres. Make entries in Table 3.1. Why did you label some fibres as artificial? You have read in your previous classes that natural fibres like cotton, wool, silk, etc., are obtained from plants or animals. The synthetic fibres, on the other hand, are made by human beings. That is why these are called synthetic or man-made fibres.

Journal of Polymers and the Environment, 2002

The aim of this paper is to provide an update on the ongoing research of our laboratory in the field of polymeric materials derived from biomass components. The first section deals with the oxypropylation of different vegetable or animal biomass residues and the use of the ensuing polyols in different polyurethane formulations. Thus, foams, elastomers, and membranes were obtained and their properties compared favorably with those of equivalent materials prepared from petroleumbased sources. The second section is devoted to furan copolymers and their use in reversibly crosslinked elastomers via the Diels-Alder reaction and in the field of photosensitive materials. The third section describes novel approaches to the surface modification of cellulosic fibers to be employed in composite materials with polymeric matrices, consisting in the use of organometallics and siloxanes as coupling agents. The final two sections are devoted to a brief outline of the role of lignins and vegetable oils as additives in printing inks, varnishes, and paints.

Russian Chemical Reviews 91(12):RCR5062, 2022

The main challenge of modern polymer science is to search for ways of further development of polymer civilization, which obviously includes living organisms on the Earth, without harmful consequences for civilization and the planet in its entirety. The review considers approaches to handle the problem of environmental accumulation of plastic waste. Promising trends in the development of polymer technologies, which can significantly reduce the amount of waste produced, are highlighted. Separate Sections address original methods of additive manufacturing technologies, such as the extrusion printing technique to produce multilayer films, 3D printing by using high-temperature polyimide materials, new functional siloxane oligomers and hydrogels for medical uses. Much attention is paid to the development and applications of biodegradable materials in medicine, packaging industry and agriculture. An analysis of the European strategy for plastics and plastic disposal demonstrates that it has a number of limitations due to high energy requirements and changes in Earth's carbon balance. The modern approach to plastic waste management free from these shortcomings is briefly outlined.

International Journal of Research Publications in Engineering and Technology [IJRPET], 2017

Polymers find a very special place in our life and day to day activities. In fact, it will not be an overstatement if we emphasize that they are now an essential and fundamentally needed part of our everyday living, and the very thought of replacing the same with any other alternative leaves even the most ingenious, innovative and dexterous scientist mentally disabled, wondering how to run their scientific skills further. Polymers as we know are macromolecules extremely long repetitive molecules with n number of repetition. In fact, they have existed in our lives since the primitive era. The natural polymer like DNA, proteins, cellulose which have been there since human birth, are also polymers. People have been using polymers even though polymers of natural origins since a very long time or time immemorial. Environmental sustainability issues of synthetic polymers have always been a burning issue for environmentalists. The innovation of Green product, or environmentally sustainable polymers are being recognized as the hope for better quality of life. Green product innovation by interaction between innovation and sustainability has become a strategic priority for all. Though the introduction of synthetic polymers in our everyday use has eased out various activities in human life, but the sustainability issue of non biodegradability later rang the alarm bell for many environmental scientists. The most worthwhile option for dealing such issues sagaciously would be developing newer technologies either involving the usage of natural polymers, stringently following the green chemistry laws while production, or newer techniques of biodegradability and recycling may be implemented which can be tested for marketplace success. Keywords: Polymers, sustainability, biopolymers, environment, technology, plastics, biodegradability. KEYWORDS: Polymers, sustainability, biopolymers, environment, technology, plastics, biodegradability.

Two identical belts designed by Elsa Schiaparelli c.1938 were assessed and analyzed due to their drastic differences in condition. Both belts are made from clear cellulose acetate (CA): one is showing severe signs of degradation and the other is in pristine condition despite being owned by the same custodian and sharing the same museum environmental histories. Chemical and physical degradation is a well-known phenomenon concerning CA objects. This paper presents a comparative study of the belts using various methodologies, which help characterize the differences in both belts. The use of linear polarized light filters to examine the polymeric matrix of the two belts is introduced. This method highlights any residual strain in clear plastics, identifying points of weakness. The occurrence of mechanical fractures resembling ellipsoid cracks in the degraded belt indicating the direction of force are presented. Fourier Transform Infrared micro-spectroscopy (micro-FTIR), Pyrolysis-Gas Chromatography/ Mass Spectrometry (Py-GC/MS) and Evolved Gas Analysis (EGA) confirms advanced acid hydrolysis of the one of the belts identifying cellulose-degradation products, as well as phthalic acid from phthalate plasticizers. Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDS) was useful to assess sulfur and phosphorous content in the formulation.