Sustainable Biopolymers

In recent years biodegradable polymers have widely attracted considerable attention as an eco-friendly alternative for the currently used hazardous textile chemicals and auxiliaries for textile modification and functionalization [10,18, 37, 72,132]. As a consequence of their unique properties such as abundance, renewability, biocompatibility, biodegradability, and environment friendliness (thereby leading to economic, environmental, and social positive impacts), a vast number of biodegradable polymers have 

By direct extraction from bio-mass 1. Aliphatic Polyester, e.g.. 

Proteins, e.g., collagen, gelatin, corn zein. - Often based on terephthallc acid, e.g.. 

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Applications of Sustainable Biopolymers in Functionalization of Cellulosic Textiles... 

To ensure further development and application of sustainable biopolymers in multi-functionalization of cellulose textile products, the following challenges should be taken into consideration. 

The future potential for application of sustainable biopolymers and derivatives to add a wide range of functionalities to cellulosic textiles, requires an economical and uniform production as well as evaluation of cytotoxicity of these products for full-scale implementation to assure the reproducibility and durability of the imparted functions together with a consumer safety... 

In order to progress beyond our current limits, it seems necessary to better study natural processes and materials in order to incorporate them into the production of more bio-compatible and sustainable biopolymer-based photonic structures with novel functionalities. ... 

Chitosan-Starch Ecocomposites Sustainable Biopolymer Matrix Reinforced with Green Fibers... 

The need of modern science to achieve a sustainable future development has been shown in many circumstances in society. Finding strategies less harmful to the environment has been a quest for research in several areas, such as pharmaceuticals, biotechnology, and food industries. With that purpose, the increase in research and development of more applications of xylan and its derivatives has shown the versatility of this biopolymer, thus helping the search for sustainable alternatives. 

Partially deacetylated chitin, a cellulose-like biopolymer consisting predominantly of N-acetyl-D-glucosamine chains, in the form of films or crosslinked hydrogels has been used for the delivery of drugs (28,29). The suitability of chitin as a vehicle for the sustained release of drugs was examined using indomethacin and papaverine hydrochloride as model drugs (30). In vitro studies showed that over 80% of the indomethacin was released within 7 hr, whereas papaverine hydrochloride dissolved almost immediately. 

This first strategy was used by Setton and coworkers to trigger the in situ formation of an ELP-based dmg depot for sustained release. Biodistribution studies of radiolabeled LLPs with a below body temperature were performed after intra-articular injection in rats [94]. Later, dmg depots of ELPs with covalently attached immunomodulator therapeutics [95] and anti-TNLa therapeutics [96] were created. Respectively, ELP[V-120] and ELP[V-60] biopolymers with a transition below body temperature were used in these studies. 

Patel, M. and Narayan, R. (2005). How sustainable are biopolymers and biobased products The hope and the reality. In Natural Fibres, Biopolymers and Their Biocomposites, ed. Mohanty, A. K., Misra, M. and Drzal, L. T. Boca Raton (USA) CRC Press, pp. 833-853. 

The surface tension of polymers (synthetic polymers such as plastics, biopolymers such as proteins and gelatin) is indeed of much interest in many areas. In industry where plastics are used, the adhesion of these materials to other materials (such as steel, glass) is of much interest. The adhesion process is very complex since the demand on quality and control is very high. This is also because adhesion systems are part of many life-sustaining processes (such as implants, etc.). The forces involved in adhesion need to be examined, and we will consider some typical examples in the following text. 

Biodegradable drug carriers composed of biopolymers or hpid membrane vesicles (liposomes) can be used to formulate protein drugs in colloidal or suspension dosage forms. These biodegradable carriers can release incorporated protein in a controlled and sustained manner. 

Electrostatic and non-electrostatic biopolymer complexes can also be used as effective steric stabilizers of double (multiple) emulsions. In this type of emulsion, the droplets of one liquid are dispersed within larger droplets of a second immiscible liquid (the dispersion medium for the smaller droplets of the first liquid). In practice, it is found that the so-called direct water-in-oil-in-water (W/O/W) double emulsions are more common than inverse oil-in-water-in-oil (O/W/O) emulsions (Grigoriev and Miller, 2009). In a specific example, some W/O/W double emulsions with polyglycerol polyricinoleate (PGPR) as the primary emulsifier and WPI-polysaccharide complexes as the secondary emulsifying agent were found to be efficient storage carriers for sustained release of entrapped vitamin Bi (Benichou et al., 2002). 

One area of particularly promise is the engineering of biopolymers in order to make them fold into a predefined 3 dimensional structure. This is a prerequisite to the construction of nanometer sized units with fixed geometry that can sustain a desired function and eventually may lead into "nanotechnology" which is the prudent exploitation of dedicated noncovalent interactions that have been unraveled before with small model compounds. 

It is well known that polysaccharide cellulose is - in general - a very important and fascinating biopolymer and an almost inexhaustible and sustainable polymeric raw material. The trend towards renewable resources and the tailoring of innovative products for science, medicine, and technology has led to a global renaissance of interdisciplinary cellulose research and the use of this abundant organic polymer over the last decade [1]. 

The situation is different for aqueous species of humic substances, the organic matter in soil that is not identifiable as unaltered or partially altered biomass or as conventional biomolecules.21 Humic substances comprise organic compounds that are not synthesized directly to sustain the life cycles of the soil biomass. More specifically, they comprise polymeric molecules produced through microbial action that differ from biopolymers because of their molecular structure and their long-term persistence in soil. This definition of humic substances implies no particular set of organic compounds, range of relative molecular mass, or mode of chemical reactivity. What is essential is dissimilarity to conventional biomolecular structures and biologically refractory behavior. 

What types of polymeric structures, other than proteins built from the standard 20 amino acids, might support catalysis in water For example, can 2-amino-2-methyl-carboxylic acids, which have been found to be enantiomerically enriched in meteorites, be the basis for a catalytic system In the absence of biopolymers, would selected monomers provide catalysis sufficient to sustain life ... 

Suspension polymerization, 94-95 Sustainable development, 199 Sustained-release drugs, 187 Syndiotactic polymers, 104, 261 Synthesis of polymers, 5, 34, 83-115. See also Polymerization biopolymers, 27-28, 43 deliberate, to promote degradation, 183 dendrimers, 110-113, 112-113 solid-phase, 32 Synthetic polymers, 5-7, 8 abiotic degradation of, 182 advantages of, 7-8 categories of, 6-7, 7 cost of, 8 density of, 7-8 first, 56-57... 

Brand owners and consumer will have a key role to play in the growth of this industry over the next five to ten years. Buyers are indeed beginning to recognise the marketing value of sustainable materials and are starting to endorse this biopolymers movement. It is education and awareness along with the cost and performance improvements that will take sustainable materials out of niche market status. 

Perhaps one of the biggest hurdles for the adoption of biodegradable and compostable materials has been the lack of kerb-side collection and municipal composting facilities, particularly in the USA and parts of Europe. Municipal composting would complete the circle for materials such as biopolymers, which start as natural renewable resources and degrade back to useable compost material. The wider development of a composting infrastructure would permit a realisation of the marketing benefits that seems to drive the adoption of sustainable materials. 

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