Classification,characterization, and the production processes of biopolymers used in the textiles industry

This article is focused on biopolymers as intelligent environmentally friendly polymers, the production processes, and coatings of biotextiles used in different industries for next generation environmental applications. Furthermore, classification and composition of biodegradable polymers, the theoretical techniques, and factorial experimental designs for the optimization of processes with intelligent biotextiles used as an alternative to commercial chemical-based textiles at reasonable cost with a zero to low environmental footprint are discussed. This article will also provide how these novel modeling methodologies will assist polymer designers in making the best decision. The present work also discusses how the fully biodegradable polymers support the textiles industry by decreasing the processing energy, material, and manufacturing costs. Finally, current development as well as potential future applications and trends of biodegradable polymers in modern biodegradable textiles industry will be presented.     

Composite materials with bast fibres: Structural,technical, and environmental properties

Natural abundance, low density, high strength per unit weight, and biodegradability of lignocellulosic materials, specifically natural fibres, render them attractive for reinforcement of engineered polymer systems. However, poor thermal stability and water resistance, coupled with poor interfacial adhesion to petroleum based polymers, has bottlenecked the application of natural fibres in composite materials. Hence, a number of different methods to improve their adhesion to polymers have been studied. In this review, an overview of the most common and simple modification systems for bast fibres from 2005 to 2015 is summarized. Also, a portion of the communication has been devoted to polymer systems, specifically examining the established petroleum based platforms and promising biopolymers. Finally, economic and environmental awareness has forced researchers to model their systems using different methodologies to assess the potential impacts. As a result, a comprehensive section discussing life cycle analysis and techno-economic analyses are presented.     

Environmental Effects on the Properties of Biopolymer Service-ware Products

The current trend towards sustainability has promoted a new interest in biodegradable plastics. Although there have been many studies on the behavior of biodegradable plastics, the changes in properties that may occur during use have not been fully documented. The mechanical properties of seven commercial service-ware items produced with biodegradable plastics were analyzed in this investigation. The effects of UV exposure, humidity, and accelerated aging on the mechanical properties were studied. In general, samples from polylactic acid and wheat straw had properties comparable to traditional synthetic plastics used in this application. However, the strength of other polymers such as bagasse, fiber pulp and potato starch was less than that of comparable synthetic plastics. The mechanical properties of the biopolymers generally deteriorated significantly upon exposure to UV radiation and humidity, with polylactic acid, wheatstraw, potato starch, and the bamboo bulrush wheatstraw blend being affected the most. Accelerated aging data indicate that after 6 months under ambient conditions, the potato starch, wheatstraw, and bamboo bulrush wheatstraw blend have a significant reduction in strength and modulus. In general, the thermal analysis behavior of most of the plastics was similar indicating a major weight loss of about 69–97% over a temperature range of 250–400?C. Additional improvements may be necessary to increase the environmental resistance of these biopolymers so that they can be effective replacements for traditional plastics.     

Establishing the Most Suitable Storage Conditions for Microencapsulated Allspice Essential Oil Entrapped in Blended Biopolymers Matrices

The adsorption isotherms of allspice essential oil microencapsulated in biopolymers blend (whey protein concentrate [WPC], mesquite gum [MG], and maltodextrin DE10 [MD]) in different proportions (WPC17%-MG17%-MD66% w/w and WPC66%-MG17%-MD17% w/w) with wall-to-core material ratios of 4:1 were determined at 25, 35, and 40°C. The isotherms were fitted using the Guggenheim-Anderson-de Boer (GAB) model and the enthalpies and entropies, both differential and integral, were estimated by the Clausius-Clapeyron method. The minimum integral entropy was considered as the point of maximum stability where strong bonds between the adsorbate and adsorbent occurred, and water would be less available and likely to participate in spoilage reactions. The point of maximum stability was found between 13.79 and 15.11 kg H₂O/100 kg d.s. (corresponding to water activity, a _W , of 0.444–0.551) for the microcapsules with WPC17%-MG17%-MD66% w/w as wall material and 18.71–19.63 kg H₂O/100 kg d.s. (a _W  = 0.591–0.713) for the microcapsules with WPC66%-MG17%-MD17% w/w as wall material in the temperature range studied.     

Mechanically reinforced biodegradable nanocomposites. A facile synthesis based on PEGylated silica nanoparticles

Biodegradable nanocomposites consisting of poly(?-caprolactone) (PCL) reinforced by PEGylated silica (polyethylene-glycol/SiO₂) nanoparticles were prepared by a melt-extrusion process. The PEGylated silica nanoparticles were prepared in a facile, one-pot synthesis process. Transmission electron microscopy (TEM) observations of the PEGylated silica nanoparticles inside the PCL matrix indicated that a homogeneous dispersion had been achieved. As a result, the storage modulus (E′) in the rubbery plateau increased significantly with the filler contents at all temperatures studied, at values approximately 45% higher than the neat PCL, at a loading level of only 4 wt.%. In comparison, in the absence of polyethylene-glycol (PEG) the silica nanoparticles formed aggregates inside the PCL matrix, and the reinforcement was negligible. The results from X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR) analyses identified the location of the PEG at the PCL/silica interface.     

Biopolymers as Carriers for Nasal Drug Delivery

Biopolymers are the most abundant raw materials that can be obtained from natural sources including bacteria, fungi, plants and even humans. The biopolymers are easily available, non-toxic, biodegradable and Generally Regarded as Safe (GRAS). These natural polymers can play an important role in the formulation of drug delivery systems by influencing the release, residence time and permeation of the therapeutic agent. The present review gives an insight into the important biopolymers and their properties in the effective delivery of the therapeutic agents systemically as well as targeting the brain via the intranasal route.     

Characterization of Gelation of Aqueous Pectin via the Ugi Multicomponent Condensation Reaction

Summary Turbidity and rheological features during gelation of semidilute solutions of pectin via the Ugi multicomponent condensation reaction have been investigated at different polymer and cross-linker concentrations at ambient temperature. The gelation time of the system decreased with increasing polymer and cross-linker concentrations. At the gel point, a power law frequency dependence of the dynamic storage modulus (G’∼ω^n’) and loss modulus (G”∼ω^n”) was observed with n’=n”=n. The value of the power law exponent is about 0.6∼0.7 for all the gelling systems, which is close to that predicted (0.7) from the percolation model. The elastic properties of the gels continue to grow over a long time in the post-gel region, and a solidlike response is observed at later stages during the gelation process. The turbidity of the gelling system is higher as the polymer and cross-linker concentrations rise, but the turbidity is virtually unaffected during an extended time after the formation of the incipient gel. It was demonstrated that polymer and cross-linker concentrations could be utilized to tune the physical properties, such as transparency and viscoelasticity, of the Ugi hydrogels.     

Polylactic acid/cellulose whisker nanocomposites modified by polyvinyl alcohol

The aim of this study was to produce biodegradable polylactic acid/cellulose whisker nanocomposites by compounding extrusion and investigate the possibility to use polyvinyl alcohol to improve the dispersion of whiskers in the matrix. Two feeding methods of polyvinyl alcohol and cellulose nanowhiskers were used and evaluated, dry-mixing with polylactic acid prior extrusion or pumping as suspension directly into the extruder. Various microscopic techniques, tensile testing, and dynamic mechanical thermal analysis were used to study the structure and properties of the nanocomposites. Due to immiscibility of the polymers, phase separation occurred with a continuous polylactic acid phase and a discontinuous polyvinyl alcohol phase. The whiskers were primarily located in the polyvinyl alcohol phase and only a negligible amount was located in the polylactic acid phase. This inadequate dispersion of whiskers in the polylactic acid phase was probably the reason why no improvements in thermal properties were seen for the nanocomposites. The relative small improvements in tensile modulus, tensile strength, and elongation to break for the nanocomposites also indicated that it was principally the polyvinyl alcohol phase that was reinforced with whiskers but not the polylactic acid phase.