Environment-friendly Polymer Research Articles

Design of biodegradable PCL/PI films as a joining tape for grafting plant

ABSTRACTIn this study, novel eco-friendly blends based on environmental-friendly polymers and compatibilizers, such as poly(ϵ-caprolactone) (PCL), cis-1,4-polyisoprene (PI), soybean lecithin (SOLE) and acrylated-epoxidized soybean oil (AESO), have been prepared in order to suggest a biodegradable joining tool used for plant grafting in agriculture, which will be competitive from the environment and economic points of view against conventional nonbiodegradable tools. PCL/PI blends, in which the portion of PCL was 75 and 50, were mixed with a compatibilizer by a melt-blending technique. The resulting blends were investigated by thermogravimetric analysis, differential scanning calorimetry and scanning electron microscopy and also their mechanical properties were determined. Afterwards, the blend films were buried in the soil. Remarkable level of weight loss was achieved in 6 weeks, ∼46%. The results showed that the addition of SOLE helped to improve the compatibility between PCL and PI due to its amphipathic property, and, besides, accelerated the weight loss of the films in soil, increasing microorganism growth on the film.

Progress in bio-based polyamides

Bio-based polyamides are environment-friendly polymers. The precursors of bio-based polyamides come from bio-based materials such as castor oil, glucose and animal oil. Bio-based polyamides precursors include bio-based amino acids, bio-based lactams, bio-based diprotic acid and bio-based diamines. In this paper, we discussed the route of the precursors of bio-based polyamides that come from bio-based materials. We discussed the properties of bio-based polyamides. Bio-based PA11and bio-based PA1010 are well-known bio-based polyamides; we discussed the origin materials of the precursors, the route of manufacturing bio-based PA11 and PA1010, and their modifications status. The variety, classification and commercial production of bio-based polyamides were described in details, as well as bio-based polyamides development in China.

Preparation and Characterization of All-Biomass Soy Protein Isolate-Based Films Enhanced by Epoxy Castor Oil Acid Sodium and Hydroxypropyl Cellulose.

All-biomass soy protein-based films were prepared using soy protein isolate (SPI), glycerol, hydroxypropyl cellulose (HPC) and epoxy castor oil acid sodium (ECOS). The effect of the incorporated HPC and ECOS on the properties of the SPI film was investigated. The experimental results showed that the tensile strength of the resultant films increased from 2.84 MPa (control) to 4.04 MPa and the elongation at break increased by 22.7% when the SPI was modified with 2% HPC and 10% ECOS. The increased tensile strength resulted from the reaction between the ECOS and SPI, which was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). It was found that ECOS and HPC effectively improved the performance of SPI-based films, which can provide a new method for preparing environmentally-friendly polymer films for a number of commercial applications.

Environmental friendly polymers based on schiff-base reaction with self-healing, remolding and degradable ability

In this paper, we have synthesized crosslinked polymers that can be remolded, self-healing and degradable, which provide us more freedom on how to treat the crosslinked polymer after they are damaged or out of use. This type of crosslinked polymer is fabricated by dynamic bonding linkage based on Schiff base reaction between commercial available terephthalaldehyde (A2) and diamine (B2) using tri(2-aminoethyl)amine (B3) as crosslinking agent. The network could be easily tailored by changing the ratio of B3 to B2 (R) and increasing R could lead to increasing the crosslinking degree. As a result, the sample could be gradually changed from weak to strong materials with increasing R based on the data of mechanical properties. Most of important, this type of crosslinked polymers could show good self-healing and remolded behavior. The crosslinked sample could also be remolded at 120 °C under hot pressure without the compromise of its mechanical properties and the temperature for self-healing could be controlled from room temperature (∼20 °C) to 55 °C based on the different R. In the meantime, they could also be completely degraded into small molecules under the acidic condition for 2 days. All these characters could provide an ideal solution to the crosslinked polymers which is totally friendly to the environment.

Facile Synthesis of Porous Silicon Nanofibers by Magnesium Reduction for Application in Lithium Ion Batteries.

We report a facile fabrication of porous silicon nanofibers by a simple three-stage procedure. Polymer/silicon precursor composite nanofibers are first fabricated by electrospinning, a water-based spinning dope, which undergoes subsequent heat treatment and then reduction using magnesium to be converted into porous silicon nanofibers. The porous silicon nanofibers are coated with a graphene by using a plasma-enhanced chemical vapor deposition for use as an anode material of lithium ion batteries. The porous silicon nanofibers can be mass-produced by a simple and solvent-free method, which uses an environmental-friendly polymer solution. The graphene-coated silicon nanofibers show an improved cycling performance of a capacity retention than the pure silicon nanofibers due to the suppression of the volume change and the increase of electric conductivity by the graphene.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-1132-8) contains supplementary material, which is available to authorized users.

A Study on the Role of Pre-Gelatinized Starch (PGS) in the Non Damaging Drilling Fluid (NDDF) for the Tipam Sand of Geleki Oilfield of Upper Assam Basin

The drilling of the wells from surface to target location with conventional drilling fluids may impair production and ultimate recovery by failing to adequately connect the reservoir with the wellbore by damaging the producing interval. One of the most common ways of damaging a formation is the filtration loss. Non Damaging Drilling Fluid (NDDF) is a clay and barite free environmental friendly polymer mud system mostly used in pay zone sections of development wells and specifically in horizontal drilling to avoid formation damage. Starches [(C6H10O5) n] are an environment-friendly drilling mud additive for water-base drilling fluids used to control the filtration loss. This paper reports the effect and optimum composition of Pre-Gelatinized Starch (PGS) as a filtration control component in the NDDF. PGS is a high-quality nonionic polysaccharide having the Chemical Formula: C27H48O20 and Molecular Weight: 692.658020 [g/mol] which controls the filtration loss by sealing the walls of the borehole due to its long chains of monosaccharide. Some clay specifically the montmorillonite a member of the smectite group that generally also found in the payzones of Geleki Oilfield of Upper Assam Basin absorb hydrogen ions into their structure when comes in contact with fresh water and causing swelling of the clay resulting in a reduction of the pore volume and possibly plug in the pore throats. Therefore the filtration loss should be as low as possible by forming high quality low permeable mud cake of as thin as possible. In this work, an attempt has been made to study the effect of varying composition of PGS on the different mud properties of laboratory formulated NDDF and to choose its optimum composition based on the required mud parameters of the study area.Int J Appl Sci Biotechnol, Vol 3(2): 291-300 DOI: http://dx.doi.org/10.3126/ijasbt.v3i2.12552

Colloids of semiconducting polymers for high-performance, environment-friendly polymer field effect transistors

Considering the recent rapid growth of polymer field effect transistor (PFET) techniques and environmental pressure to avoid the use of toxic organic solvents in industrial processes, it is very important to develop colloids of semiconducting polymers in non-toxic solvents. Herein, we demonstrate the fabrication of surfactant-free, emulsion-dispersed nanoparticles of donor–acceptor copolymers. By optimizing the deposition methods of such semiconducting polymer colloids, high mobility (2.7cm2/Vs) PFETs were fabricated via environmentally benign processes. Systematic analyses on the crystalline nature of the colloid-processed films revealed that the well-developed edge-on lamella structure comparable to that of the bulk polymer, was preserved during the colloid-fabrication processes.

Fractal geometry analysis of chemical structure of natural starch modification as a green biopolymeric product

Public concerns and official pressures around environmental protection as well as exhausting petroleum resources have brought about preferences in studying and applying environmental-friendly polymers instead of synthetic petroleum-based polymers. For this aim, biopolymers can have outstanding advantages in biodegradability by saving time, energy and effort spent on increasingly costs of polymeric wastes. Natural starch (being studied in this work), as one of the most abundant natural resources for polymer materials, is inexpensive and biodegradable. As starch necessarily needs for modifications and processing before being used as ideal green polymer material, it is vital to perform feature extraction and defect detection measures in structure by some method like image analysis. Fractal as a new geometry has circumstantially progressed recently in the fields of image processing, physical space–time, medical image analysis, electrochemical patterns, digital images, sounds etc. Box Count Fractal Dimension as a very important and popular part of fractal geometry can be a useful factor in feature extraction and pattern recognition. This paper presents a new method for defect detection in the structure of natural starch modification images using the fractal dimension (FD) along with mean and standard deviation of image color. This is performed via feature extraction based on artificial intelligence by MatLab R2013a for box counting algorithms. Otsu’s graythresh method by MatLab R2013a is applied to binarize the images. The results of proposed methodology are illustrated as log–log curves where the fractal dimensions are recognized by curve fitting (CF) tool with more than 95% accuracy. The outputs express that starch samples’ FD vary in the range from 1.636 to 1.926 among which the last is identified as non-defective polymer. Non-defective feature is of great importance for quality control measures and chemical reactivity being here highlighted as biodegradability.

Spectral Analysis and Determination of Palladium II Based on the Environment-Friendly and Water-Soluble Polymer

ABSTRACT The environment-friendly and water-soluble polymer was prepared via ring-opening reaction between polyvinyl alcohol (PVA) and 3-epoxypropoxy fluorescein (EPF). Based on the quenching of fluorescence signals of PVA–EPF in the 520 nm wavelength and relative quenched intensity is good linear with the concentration of palladium II. A simple, rapid, sensitive, and specific detection method for palladium II is proposed. In comparison with traditionary methods, the present method is environment-friendly, stable, easy to operation, more water-soluble, and cheaper. The results suggested that PVA–EPF may offer potential as a reusable polymer sensor for palladium II ion in aqueous solution.

Sound power levels of the Caxirola and different types of caxixis

In 2014, Brazil will host the FIFA World Cup and Brazilian Musician Carlinhos Brown created the caxirola as the official music instrument, adapting an old African instrument—the caxixi. In both instruments, the sound is generated by hard particles impacting on the walls of a closed basket. While the caxirola is made of environmental-friendly polymer, the caxixi is handcrafted of natural components. At a previous ASA meeting [Pozzer and Paul, J. Acoust. Soc. Am. 134(5), 4187 (2013)], we presented both instruments and sound pressure levels measured at users ears. Being handmade makes the caxixi to be highly variable in size and proportions, in contrast to the caxirola which is an industry product. We now present sound power level (SWL) measurements made by the hemi-anechoic room method and the reverberation chamber method. The SWL measured for the caxirola was 79 to 86 dB (80 to 85 dBA) for transversal and longitudinal use, respectively. The SWL of four different caixixis measured ranged between 69 and 80 dB (70 to 79 dBA). Octave band SWLs were found to be higher for the caxirola compared to all four caxixi in the 500 Hz to 4 kHz bands.

Thermoresponsive microhydrogels: preparation, properties and applications

A microgel is a fascinating type of soft matter. Among the various microgels, great interest has been shown in microhydrogels because their functions are realized in water, which is the most benign liquid to humans. The microhydrogel-composing polymers have their own delicate hydrophilic − hydrophobic balance, which is sensitive to environmental conditions such as temperature, pH, ionic strength, light and specific (bio)molecules, in many cases. This review describes the methodology for the preparation of such microhydrogels, their properties, and finally their applications in physicochemical, biological and biomedical, optical and photonic, and chemical fields. The main material cited is a representative temperature-sensitive polymer, poly(N-isopropyl acrylamide), but some other environment-friendly polymers such as cellulose derivatives are also reported. © 2013 Society of Chemical Industry

Environmental Friendly Polymer Materials for Sustainable Development

1 Key Laboratory of Rubber-Plastics (Ministry of Education), Qingdao University of Science and Technology, Shandong, Qingdao 266042, China 2 Trent Biomaterials Research Center, Trent University, Peterborough, ON, Canada K9J 7B8 3Department of Materials Engineering, Monash University, Melbourne, VIC 3800, Australia 4Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

Toughness and Compatibility Improvement of Thermoplastic Starch/Poly(lactic Acid) Blends

Poly (lactic acid) (PLA), produced from renewable resources, is one of the most widely used biodegradable polymers. PLA has high strength and high modulus. However, its brittleness and high cost limit its application. Starch has been used as filler for environmental friendly polymers due to its low cost, biodegradable, and availability as a renewable source. Thermoplastic starch (TPS) is a biodegradable material based on starch. Incorporation of TPS into PLA matrix can reduce material cost and increases its biodegradation rate. However, PLA and TPS form immiscible blend leading to poor mechanical properties of the blend. The compatibility of the blend can be improved by adding compatibilizers. Moreover, in order to improve toughness of the TPS/PLA blend, poly (butylenes adipate-co-terephthalate) (PBAT), is introduced into the blend. In this study, PLA/TPS blends are prepared using an internal mixer and test specimens are molded using a compression molding. TPS is obtained from cassava starch and glycerol at ratio of 70/30 wt%. The ratio of TPS/PLA blend is 10/90 wt%. Poly (lactic acid) grafted maleic anhydride (PLA-g-MA) is used as a compatibilizer at contents of 3, 5, and 7 phr. PBAT content is 10 wt%. Mechanical, morphological, and thermal properties of the blends are investigated.

The role of sodium alginate in improving floc size and strength and the subsequent effects on ultrafiltration membrane fouling

Background: Dosing environment-friendly polymer as coagulant aids is an encouraging method in water treatment to obtain desirable floc characteristics. Sodium alginate (SA) was used as the coagulant aid for synthetic humic acid (HA) water treatment to investigate the effect on flocs characteristics and ultrafiltration (UF) membrane fouling. Results: When SA content was 0.3 mg L−1, the treatment of HA by polyaluminium chloride (PAC) plus SA (PAC/SA) yielded the maximum removal efficiency of 66.5%, which was higher than the maximum HA removal efficiency of PAC (58%). Moreover, the HA flocs size of PAC would grow from 269 to 367 μm after SA was added. Strength factor and recovery factor of PAC/SA were larger than those of PAC. These resulted in the improvement in subsequent UF membrane performance. The membrane fouling decreased in the following order: the raw water>PAC coagulated water>PAC/SA coagulated water. Conclusion: The study showed that the application of SA as coagulant aids resulted in larger and stronger flocs, which would improve treatment efficiency of the coagulation process. And the flocs formed by PAC/SA contributed to the restriction of the fouling of UF membrane, which would decrease the cost of advanced water treatment.

The Production of Poly(L-lactic acid) from 2-Steps Direct Polycondensation in 100 Kg Scale

Synthesis of poly(L-lactic acid), PLLA, in a mass scale production using 2-steps direct polycondensation methods was investigated. One hundred kilogram of L-lactic acid was esterified in a designed reactor under reduced pressure at elevated temperature in the first step, followed solid state polymerization, SSP. The synthesized PLLA from both laboratory (5 g) and mass (100 L) scales show comparable melting temperature, Tm (151 – 172 oC) and molecular weight (Mn) (10,000 -32,000) at the similar polymerization conditions. The appearances of synthesized PLLA are yellow-white solid powder. The results show high potential to produce environmental friendly polymer, PLLA, using non-complex facilities process.

Studies on the thermal behavior of CS:LiTFSI:[Amim] Cl polymer electrolytes exerted by different [Amim] Cl content

The principle motivation of this research work is to develop environmental-friendly polymer electrolytes utilizing corn starch (CS), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 1-allyl-3-methylimidazolium chloride ([Amim] Cl) by solution casting technique. The highest ionic conductivity value was achieved for the composition CS:LiTFSI:[Amim] Cl (14 wt. %:6 wt. %:80 wt. %) which exhibits the ionic conductivity value of 5.68 × 10 −2 S cm −1 at 40 °C with the activation energy of 4.86 kJ mol −1. This sample possess high concentration of amorphous phase coupled with greater presence of conducting cations (lithium, Li + and imidazolium, [Amim] +) as depicted by the dielectric loss tangent plot. The conductivity–temperature plots were found to obey Arrhenius rule in which the conductivity mechanism is thermally assisted. The melting temperature of polymer electrolyte decreases with increase in [Amim] Cl content. This is attributed to the good miscibility of [Amim] Cl in CS:LiTFSI matrix inducing structural disorderliness. Reference to the TGA results it is found that the addition of [Amim] Cl diminishes the heat-resistivity whereas enhancement in the thermal stability occurred at the initial addition and declines with further doping of [Amim] Cl.

Improved thermal stability and mechanical properties of poly(propylene carbonate) by reactive blending with maleic anhydride

AbstractTo extend the application of a carbon dioxide sourced environmental friendly polymer: poly (propylene carbonate) (PPC), a small amount of maleic anhydride (MA) was melt blended to end‐cap with PPC to improve its thermal stability and mechanical properties. Thermal and mechanical properties of end‐capped PPC were investigated by TGA, GPC, mechanical test, and DMA. TGA and titration results demonstrate that PPC can be easily end‐capped with MA through simple melt blending. TGA results show that the thermal degradation temperature of PPC could be improved by around 140°C by adding MA. GPC measurement indicates that the molecular weight of PPC can be maintained after blending with MA, where pure PPC experiences a dramatic degradation in molecular weight during melt process. More importantly, the tensile strength of PPC after blending with MA was found to be nearly eight times higher than that of pure PPC. It has approached the mechanical properties of polyolefin polymers, indicating the possibility of replacing polyolefin polymers with PPC for low temperature applications. The method described here could be used to extend the applications of PPC and fight against the well known global warming problem. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Preparation, Characterization and Preliminary Trichomonacidal Effect of Poly Aspartic Acid-metronidazole Nanoprodrug*

Poly aspartic acid or its salts is a kind of newly innocuous, environmental friendly biodegradable polymer, recognized as green material, and widely applied in such areas as agriculture, medicine, commodity, water treatment. In order to prepare new poly aspartic acid-metronidazole (PASP-MTI) nanoprodrug, observe its trichomonacidal effect in vitro, and explore its probable mechanism, the nanoprodrug PASP-MTI was synthesized by DL-aspartic acid and metronidazole in a relatively mild condition. Its structural characteristics were attested by means of infrared spectrum (IR), 1H nuclear magnetic resonance (1H-NMR), transmission electron microscope (TEM) etc measurements. The release behavior of metronidazole in PASP-MTI nanoprodrug was investigated by the dialysis method. The MTT assay was employed to test PASP-MTI's trichomonacidal effect in vitro and the apoptotic-like processes of trichomonas were detected by fluorescence microscope and flow cytometer (FCM). The IR and 1H-NMR showed that the metronidazole was conjugated to poly aspartic acid high molecular chains by ester bonds. Synthesized PASP-MTI nanoprodrug was globular and had a mean diameter 404.8 nm with favorable dispersity. The drug loading was about 30% and the cumulative release profile was delayed (about 38.01% of MTI loading in the PASP-MTI nanoprodrug was released within the first 24 h and 86.64% in 30 d, while the release of free metronidazole was almost complete by 24 h). The trichomonacidal activity of PASP-MTI nanoprodrug increased remarkably{IC50 of PASP-MTI and free metronidazole was 1.22 mg/L and 2.85 mg/L, respectively}. Observed by fluorescence microscope, the nuclei of trichomonas presented a series of changes similar to apoptosis such as chromatin agglutination, nuclear fragmentation, etc. The FCM study indicated that the apoptotic rate in the PASP-MTI group was the highest of all groups, up to 35.69%. It is concluded that PASP can be effectively used in drug delivery systems, the synthetic novel poly aspartic acid-metronidazole nanoprodrug has higher drug loading, better the role of prolonged-release and higher trichomonacidal effect in vitro. Its mechanism may be related with enhancing the polymer prodrug's internalization and inducing the apoptosis of trichomonas.

Bleaching and Dyeing of Superfine Wool Powder / Polypropylene Blend Film

Fibers based regenerated protein draw much attention for recycling discarded protein resources and can produce biodegradable and environmental friendly polymers. In this study, superfine wool powder is blended with polypropylene (PP) to produce wool powder/PP blend film through extrusion and hot-pressing. Hydrogen peroxide is used to bleach the black colored surface of the blend films. The effects of peroxide concentration, bleaching time and powder content on the final whiteness and mechanical properties of the blend films are investigated. The bleached films are dyed with acid red dyes and the dyed color is evaluated using a Computer Color Matching System. Color characters of dyed films, such as L*, a*, b*, ΔE*ab, C*ab and K/S values are measured and analyzed. The study not only reuses discarded wool resources into organic powder, widens the application of superfine wool powder on polymers, but also improves the dyeing properties of PP through the addition of protein content.

Electric activity in rigid rod-like polymer, poly(β-hydroxybutyrate)

Poly(β-hydroxybutrate) (PHB), one of the most promising environmental friendly polymers, was found to be rich in electric activities. Our experimental results demonstrated that the PHB exhibited ferroelectric behavior, as well as pyroelectric behavior. A remanent polarization of the PHB system was as large as 67mC/m2 at 100°C from a displacement–field hysteresis loop, while it possessed pyroelectric coefficient as large as 20μC/m2K after a poling procedure. The remanent polarization exhibited unique temperature dependence and it increased rapidly at the temperatures higher than 80°C. The polarization due to the ester dipole ordering is likely formed in the direction perpendicular to the helical axis.