Preparation of cardanol based epoxy plasticizer by click chemistry and its action on poly(vinyl chloride)

In recent years, the using of reproducible resource and economical and efficient synthesis method has got wide concern. Herein, an environmental‐friendly plasticizer originated from cardanol was synthesized by click chemistry. First, the cardanol sulfide (CS) was obtained by click chemistry reaction between the double bond of the side chain of cardanol and mercaptoethanol. The degree of the click reaction was estimated to reach 84.7% by testing the content of sulfur. Then, the epoxidation of the hydroxyl was performed to get cardanol based epoxy plasticizer (CEP) in the presence of epichlorohydrin. The epoxy value was 0.32. The structure of CS and CEP was confirmed by FT‐IR and NMR techniques. A Haake torque rheometer was used to research the action of CEP on polyvinyl chloride (PVC). Results showed that it possessed favorable plasticization effect and stabilization effect on PVC. CEP had good heat stabilization in PVC, and could decrease the T_g of PVC significantly. Moreover, CEP could increase the tensile strength of PVC when in a small amount, and could increase the plasticity of PVC when in a larger quantity significantly. The characteristics of volatile, migration and solvent extraction of PVC plasticized by CEP is similar to by dioctyl phthalate (DOP). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44890.     

Novel flame‐retardant epoxy composites containing aluminium β‐carboxylethylmethylphosphinate

A novel flame‐retardant aluminum β‐carboxylethylmethylphosphinate [Al(CEP)] was synthesizedby a simple process. The effect of Al(CEP) on the curing of epoxy resin (EP) was investigated with differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. The flame retardancy and thermal properties of Al(CEP)/EP were analyzed by a limiting oxygen index (LOI), vertical burning test (UL‐94), scanning electron microscopy (SEM) with energy‐dispersive X‐ray (EDX), gravimetric analyses, and DSC. Results disclosed that curing of EP is delayed by incorporating Al(CEP). The flexural strength of EP is reduced but the flexural modulus is increased by adding Al(CEP). Adding Al(CEP) depresses the decomposition of EP while leads to a increase in the glass transition temperature (T_g), in char formation and in flame retardancy of EP. EP containing 25 phr Al(CEP) provides LOI of 28.3% and passes UL‐94 V‐0 rating. SEM results show that the sample passing V‐0 rating can form the condensed char whereas porous char is observed from the sample failing in V‐0 rating after combustion. EDX analysis shows that the condensed char presents higher weight ratio of carbon to phosphorus than the porous char, indicating appropriate amount of Al(CEP) is necessary for formation of the stable char. POLYM. ENG. SCI., 55:657–663, 2015. © 2014 Society of Plastics Engineers     

Effects of culture temperature on the production of bioactive polysaccharides by Agaricus blazei in batch cultures

Effects of culture temperature ranging from 20 to 34 °C on cell growth, polysaccharide biosynthesis and the bioactivity of polysaccharides of Agaricus blazei were evaluated via eight batch cultures in steps of 2 °C in a stirred tank bioreactor. Results indicated that the optimal temperature for the biomass was 28 °C with a cell yield of 780 mg g^?1, while that for polysaccharide formation was 30 °C with a product yield of 230 mg g^?1. Both the β‐glucan content and average molecular weight of the polysaccharides from different temperature‐controlled cultures were closely correlated with their tumour necrosis factor‐α (TNF‐α) release capability on macrophage cells. The polysaccharides from the low temperature range (20–24 °C) not only had higher relative content of β‐glucan and average molecular weight but also exhibited higher bioactivity compared with those from the high temperature range (30–34 °C). The optimal temperature for the production of bioactive polysaccharides of A. blazei was 24 °C, at which their relatively high molecular weight, β‐glucan content and TNF‐α release capability on macrophage cells were 1650 kDa, 188 mg g^?1 and 1560 pg per 5 × 10⁴ cells respectively. Copyright © 2007 Society of Chemical Industry     

Maximizing the Retention of Ganoderic Acids and Water-Soluble Polysaccharides Content of Ganoderma lucidum Using Two-Stage Dehydration Method

Ganoderic acids and water-soluble polysaccharides are the main bioactive ingredients of Ganoderma lucidum and are heat sensitive. Hence, it is crucial to apply a suitable drying method for the drying of G. lucidum to minimize the loss of these bioactive ingredients. In this study, a two-stage drying method was applied to enhance the drying kinetics, as well as the retention of both ganoderic acids and water-soluble polysaccharides in dried G. lucidum fruiting bodies and slices compared to other single-stage-dried products. The results showed that two-stage drying enhanced the overall drying rate, which consequently shortened the total drying time up to 61 and 330% for fruiting bodies and slices, respectively, compared to single-stage drying methods. Furthermore, two-stage drying of Ganoderma fruiting bodies, which involves 18-h vacuum drying followed by 5-h heat pump drying, maximized the retention of ganoderic acids and water-soluble polysaccharides, with the retention of 97.90% of water-soluble polysaccharides and 4.2% more ganoderic acids than freeze-dried products. On the other hand, drying of Ganoderma slices within the shortest total drying time, which is 10-min heat pump drying followed by 50-min oven drying, also retained most of the ganoderic acids and water-soluble polysaccharides in the dried products; that is, about 80% of water-soluble polysaccharides and 11% more ganoderic acids than freeze-dried slices.     

Thermal stability study of Pd-composite membrane fabricated by surfactant induced electroless plating (SIEP)

Over the years, several different methods have been developed by modifying the conventional electroless plating (CEP) technique to fabricate dense thin Pd composite membranes with high H₂ permselectivity. In this study, Pd composite membranes on macroporous stainless steel substrate (MPSS) were fabricated using CEP and novel surfactant induced electroless plating (SIEP) methods. The structural characteristics of CEP and SIEP fabricated Pd membranes were investigated before and after the heat treatment using SEM, XRD, EDS, and AFM techniques. The H₂ permselectivity performance of the SIEP membranes was compared with that of CEP at different temperatures and trans-membrane pressures in the range of 523-823 K and 20-100 psi, respectively. The long-term thermal stability test of SIEP fabricated membranes was carried out on two different membranes, fabricated on MPSS substrates with and without oxide layer at 15 psi trans-membrane pressure and thermal cycling of 573-723-573 K. The microstructure analysis revealed that SIEP membranes have finer grains and diffused grain boundaries resulting in uniform, smooth, continuous, and pinhole free Pd-film. The SIEP membrane showed eight-fold higher H₂ flux (1.7172 mol/m²/s) and four-fold higher H₂ selectivity (~148) at 823 K and 100 psi trans-membrane pressure, compared to CEP membrane. Pd/MPSS membrane subjected to test for long-term performance and thermal cycling showed stable performance up to 1200 h while maintaining infinite H₂ selectivity. Interestingly, although the thickness of Pd/oxi-MPSS (13.49 µm) membrane was higher than that of Pd/MPSS (11.6 µm) membrane, the H₂ flux of Pd/oxi-MPSS membrane was two times higher than that of Pd/MPSS, attributed to the effective action of oxide layer as diffusion barrier.     

A simple strategy for the separation and purification of water-soluble polysaccharides from the fresh Spirulina platensis

A novel and industrially applicable strategy for separating and purifying the water-soluble polysaccharides from the fresh Spirulina platensis is introduced in this study. After hot water extraction, using chitosan flocculation treatment, 86.0% of the particles and 85.9% of the pigments in the crude extract were removed. The purity of polysaccharides could be increased to 94.6% and 96.1% by applying the macroporous resin ADS-7 to remove the impurities in the mode of static adsorption and in a dynamic mode of operation, respectively. The polysaccharides obtained were composed of three major components having molecular weights of 1400, 420 and 2 kDa.     

Fractional Isolation and Structural Characterization of Lignins from Oil Palm Trunk and Empty Fruit Bunch Fibers

Abstract

The lignins from dewaxed oil palm trunk and empty fruit bunch (EFB) fibers were fractionated into 95% ethanol soluble, cold and hot water soluble, and 1% NaOH soluble lignins, respectively. The chemical and structural composition of the lignin preparations was determined by using UV, GPC, FT-IR, ¹³C-NMR spectroscopy and nitrobenzene oxidation. The alkali soluble and 95% ethanol soluble lignin fractions were found to contain low amounts of chemically linked polysaccharides, 2.9-3.9% and 7.5-8.0%, respectively, while the water soluble lignin fractions showed significant amounts of bound polysaccharides (16.2-23.3%). All of the lignin fractions contained a high proportion of non-condensed syringyl units, together with small amounts of non-condensed guaiacyl and fewer p-hydroxyphenyl units. The lignin from oil palm EFB fiber contained a significant amount of esterified p-hydroxybenzoic acid and a minor quantity of esterified glucuronic acid. Trace of ferulic acids was both esterified and etherified to lignin side chains in the EFB fiber cell walls.     

Ligand sorption kinetics of aromatic amines on new ligand-exchanger sporopollenin in cobalt ion form

An approach to study of intraparticle ion-exchange kinetics of aromatic amines such as p-chloroaniline, p-toluidine, and p-nitroaniline as ligands on Co²⁺ loaded-ligand exchanger of sporopollenin (carboxylated epichlorohydrine [CEP]–sporopollenin) is presented and the ligand-exchange reaction in the resin matrix is shown to be rate-determining. Kinetic studies of aromatic amines as ligands on the CEP–sporopollenin have been performed using continuous column runs. The observed rate seems to be related to the rate of ligand sorption with the mobile phase (ion) and pH in the aqueous phase. The rate of attainment of equilibrium sorption and breakthrough curves of aromatic amines is seen to be nearly similar. With the sorption mechanism deduced to be dominantly particle diffusion-controlled, diffusion coefficients determined were found to range from 1.10^?8 to 1.0 10^?9 cm²s^?1. Coupled with the fact that different concentrations of solution were employed, these results may be interpreted as indicating that particle diffusion is the rate-determining step; on the contrary, film diffusion was not a rate-controlling step in the ligand-sorption process under the conditions employed. © 1995 John Wiley & Sons, Inc.     

Isolation,physicochemical properties,and in vitro antioxidant activity of polysaccharides extracted from different parts of Pinus koraiensis

The isolation and purification of polysaccharides extracted from the cones, bark, and needles of Pinus koraiensis (Korean pine) were studied. The amounts of polysaccharides were 42.7%, 53.4%, and 48.4% for cones, bark, and needles, respectively. All these samples contained uronic acid. The total protein and polyphenols were <4.5% for all three samples. With acid hydrolysis, seven polysaccharides were found in different molar ratios in each sample: D-ribose, L-rhamnose, L-arabinose, D-xylose, D-mannose, D-glucose, and D-galactose. The relationships between in vitro antioxidant properties (AOP) of polysaccharides extracted from different parts of the P. koraiensis tree are correlated with physicochemical properties (the amount of neutral sugars, uronic acid, and proteins). Moreover, the pinecone polysaccharides (PKCP) confirmed previously observed beneficial antioxidant capacity with an EC₅₀ of OH radical, ABTS radical scavenging, and reducing power of 6.54, 5.06, and 9.15 mg/mL, respectively. PKCP had the best antioxidant activity among the three samples.     

Recovery of microbial polysaccharides from fermentation broths by microfiltration on ceramic membranes

This paper investigates the extraction of microbial polymers (polysaccharides) from fermentation broths of Sinorhizobium meliloti M5N1CS using crossflow filtration through ceramic membranes of various pore sizes from 0.1 to 0.8 µm. The duration of fermentation was set at 70 h in order to maximize the production of high molecular weight polysaccharides (average 2 × 10⁵ Da). The 0.1 µm membrane underwent rapid fouling and was found inadequate for this application. For the other membranes, the sieving coefficients decreased from 95% to about 20% in 90 min, at a slower rate than the permeate flux. The largest permeate and mass fluxes were obtained with the 0.5 µm membrane (18.5 × 10⁻⁶ m s⁻¹ and 20 × 10⁻⁶ gm⁻²s⁻¹). Increasing the fluid velocity from 3 to 6 m s⁻¹ increased both the permeate flux and sieving coefficients, while raising the transmembrane pressure from 50 kPa to 100 kPa increased the flux slightly but decreased the sieving coefficient. Polysaccharide extraction will be maximized by operating at high velocities and low transmembrane pressure (TMP) which may require cocurrent recirculation of the permeate. Experiments with cell‐free solutions showed that the permeate flux is mostly limited by the bacterial layer deposited on the membrane while the presence of cells has a positive effect on the sieving coefficient. Irreversible fouling due to polymer adsorption on the membrane decreased with increasing pore size and velocity but increased strongly with TMP. © 1999 Society of Chemical Industry     

Stabilization of pluronic gels in the presence of different polysaccharides

Several different polysaccharides have been added to pluronic F127 (poloxamer 407) gels to test their ability to stabilize the gels against dissolution in aqueous media over time. The studied polysaccharides include κ‐carrageenan, chitosan, hyaluronic acid, pectin, alginate, hydroxyethylcellulose, and ethyl(hydroxyethyl)cellulose. Although all the considered polysaccharides slowed down the dissolution time of the pluronic gels, unmodified polysaccharides only had a modest stabilization effect. However, hydrophobic modification of polysaccharides with a sufficiently long hydrocarbon chain (C₁₆) was found to partly prevent the gels from dissolving for more than 6 months. Shorter hydrocarbon chains did not have the same effect, even at high degrees of hydrophobicity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40465.     

Grafted polysaccharides based on acrylamide and N,N‐dimethylacrylamide: Preparation and investigation of their flocculation performances

The graft copolymerization of N,N‐dimethylacrylamide (DMA) and acrylamide (AM) were carried out onto different polysaccharide backbones separately. The graft copolymers were synthesized by ceric ion induced redox polymerization technique. Three polysaccharides were used, namely hydroxyethyl starch (HES), hydroxyethyl cellulose (HEC) and Amylopectin (AP), for the grafting reactions. Among the three polysaccharides, HEC has linear structure, while HES and AP have a branch one. The graft copolymers were characterized by intrinsic viscosity measurements, FTIR spectroscopy, NMR (both ¹H and ¹³C) spectroscopy, and thermal analysis. Flocculation performances of the graft copolymers were evaluated in 1 wt % kaolin and in 0.25 wt % iron ore suspensions. A detailed comparative study of the flocculation properties of the synthetic graft copolymers was also made. It showed that graft copolymers based on DMA were better flocculants than those based on AM. Among the synthetic graft copolymers, HES‐g‐Poly (DMA) performed best when compared with the other synthetic graft copolymers as well as to the commercial flocculants in the same suspensions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Ultrasonic-assisted enzymatic extraction and antioxidant activity of polysaccharides from Setaria viridis

Ultrasonic-assisted enzymatic extraction (UEAE) and response surface methodology (RSM) were used to isolate polysaccharides from Setaria viridis (SVP). Optimal extraction conditions in the enzymatic hydrolysis process were: extraction duration, 68 min; extraction temperature, 51°C; ratio of enzyme to raw material, 1.6%; and ratio of liquid to raw material, 20 mL/g. Then, following ultrasonic treatment (180 W, 60°C, 60 min), the experimental yield was 8.94 ± 0.38%. Crude SVP was purified by DEAE cellulose-52 chromatography and Sephadex G-100 chromatography, resulting in the isolation of three fractions (designated SVP-1, SVP-2 and SVP-3). These SVPs were mainly composed of glucose residue, and SVP-3 had a significantly higher uronic acid content than the other two fractions. Additionally, all fractions showed strong antioxidant activities in vitro.     

Supercritical fluid extractive fractionation: Study of the antioxidant activities of Panax ginseng

This study aimed to investigate the contents and the antioxidant activities of various fractions from ethanol extract of the root powder of Panax ginseng C. A. Meyer using supercritical carbon dioxide (SC-CO₂) fractionation technology. Results showed that the DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals scavenging activity was higher in the residue and Fraction 1 compared with that in the extract. Increasing amounts of total phenolic compounds, total polysaccharides, and saponins were strongly correlated with a higher antioxidant capacity. SC-CO₂ extractive fractionation technology could effectively fractionate the bioactive ingredients from Panax ginseng C. A. Meyer and increase the antioxidant activities of its fractions.     

Construction of gold nanoparticles by tubular polysaccharide from black fungus and their apoptosis-inducing activities in HepG2 cells

Gold nanoparticles (AuNPs) with size of 12 ~ 25 nm were loaded on the dendritic nanotubes (DNTs), which were self-assembled by the triple-helix polysaccharides from black fungus (AF1). The characterization results proved that the AuNPs were dispersed on the surface of DNTs without affecting their tubular structure. Due to the dendritic structure, the loading content of AuNPs could arrived at 46.4%. Moreover, the potential anticancer activities of the complex (DNT-Au) were evaluated by the induction of apoptosis in HepG2 cells. It was found DNT-Au could be taken up by cells and enter into lysosomes, further inducing apoptosis in HepG2 cells by ROS-mediated mitochondrial dysfunction. This work was benefit for the development of natural polysaccharide as a substrate to stabilize nanoparticles in biomedical fields.     

Resistance of Valonia cellulose to mercerization

The mercerization behavior at 20°C. of Valonia macrophysa cellulose of Japanese origin was investigated by x-ray, moisture regain, and infrared spectrographic methods. The NaOH concentration range necessary for mercerization was 16–20%, which is higher than those required for wood pulp (8–11%), ramie or cotton (11–14%), and even the animal cellulose, Tunicin (14–16%). Treatment with the alkaline solution of the ordinary concentration (17.5%) for 4 days could not mercerize it, and even mercerization with a 19% solution brought about the presence of the reflection from (101)_II along with those from (101 )_I and (101)_I after regeneration. Such a high resistance to mercerization of the Valonia cellulose may be due to its larger crystallite size rather than the crystalline content.     

Studies on self‐assembly interactions of proteins and octenyl succinic anhydrate (OSA)‐modified depolymerized waxy rice starch using rheological principles

Dynamic tests (23 °C, pH ～ 7.0) yielding relaxation times, λ, as a function of frequency and polymer concentration were performed to assess self‐assembly characteristics of biopolymers in aqueous solution. Reduction of λ‐values (slope) up to a critical frequency value (CFV) helps characterize structure formation. Proteins and octenyl succinic anhydrate (OSA)‐modified depolymerized waxy rice starch (DWxRc) show a well‐defined λ‐slope at all concentrations. Except for whey protein isolate (WPI, 0.184 g/L) and 7% OSA‐modified DWxRc (1.84 g/L), the λ‐values of the solutions are comparable (P > 0.05), indicating similar structures. Self‐assembly interaction of α‐lactalbumin (3.68 g/L) with OSA‐modified polysaccharides is observed with 18.4 g/L of 7% OSA‐modified DWxRc (CFV of 0.08 Hz), while WPI (3.68 g/L) exhibits self‐assembly with all polysaccharides and concentrations. Transmission electron microscopy (TEM) of electrostatically precipitated proteins alone or in combination with OSA‐modified polysaccharides confirms that λ?slope and CFV values relate to shape, size, and shear stability of the assembled structures. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43603.     

Analysis of volatile compounds and triacylglycerol composition of fatty seed oil gained from flax and false flax

Linseed (Linum usitatissimum, L.) and camelina (Camelina sativa, L.) are ancient crops containing seed oils with a high potential for nutritional, medicinal, pharmaceutical and technical applications. In the present study, linseed and camelina oils of plant varieties grown under Central European climate conditions were examined with respect to their volatile and triacylglycerol (TAG) components. Solid‐phase microextraction was applied to the study of volatile compounds of several linseed and camelina oils, which have not been described prior to this publication. Hexanol (6.5–20.3% related to the total level of volatiles), trans‐2‐butenal (1.3–5.0%) and acetic acid (3.6–3.8%) could be identified as the main volatile compounds in the linseed oil samples. Trans‐2‐butenal (9.8%) and acetic acid (9.3%), accompanied by trans,trans‐3,5‐octadiene‐2‐one (3.8%) and trans,trans‐2,4‐heptadienal (3.6%), dominated the headspace of the examined camelina oil samples. TAG were analysed by MALDI‐RTOF‐MS and ESI‐IT‐MS, providing information about the total TAG composition of the oils as well as the fatty acid composition of the individual components. More than 20 TAG could be identified directly from whole linseed oil samples, mainly composed of linolenic (18:3), linoleic (18:2) and oleic (18:1) acid, and to a lesser degree of stearic (18:0) and palmitic (16:0) acid. While in linseed these TAG comprise more than 60% of the oils, Camelina sativa exhibited a wider range of more than 50 constituents, with a considerable amount (>35%) of TAG containing gadoleic (20:1) and eicosadienoic (20:2) acid.     

Effects of culture pH on the production of bioactive polysaccharides by Agaricus blazei in batch cultures

The effects of culture pH on the production, molecular weight distribution and the bioactivity of polysaccharides produced by Agaricus blazei were evaluated by four pH‐controlled batch cultures. As the culture pH of each batch was controlled from 4.0 to 7.0, the maximum polysaccharide concentration increased from 561 to 1252 mg dm^?3, but the average molecular weight of the polysaccharides decreased monotonically from 1080 kDa to 600 kDa, the relative amount of β‐glucan from 56% to 33%, and the TNF‐α release by macrophage cells from 1440 to 760 pg per 5 × 10⁴ cells. Polysaccharides with higher molecular weights, β‐glucan contents and bioactivities were obtained in the submerged cultures of Agaricus blazei at lower culture pH but with lower yields. Copyright © 2004 Society of Chemical Industry