Coconut water as a potential resource for cellulose acetate membrane preparation

BACKGROUND: Cellulose acetate membranes are frequently used for pressure‐driven membrane processes. The aim of this work was to prepare cellulose acetate membranes from nata‐de‐coco using coconut water as starting material. The use of this lignin‐free material will certainly minimize the use of chemicals usually needed in the traditional pulps and substitute for the use of wood, which helps prevent global warming and preserves nature as well. RESULTS: Coconut water was fermented by Acetobacter xylinum for 6 days to produce nata‐de‐coco, which was then acetylated to produce cellulose diacetate with an acetyl content of 39.6%. Fourier transform infrared analysis showed characteristic peaks for the acetyl group at 1748 and 1236 cm^?1. The resulting membranes made from the hydrolysis product showed a water flux of 210.5 L m^?2 h^?1 under an applied pressure of 2 kg cm^?2 while the rejection coefficients of dextran T‐500 and T‐2000 solutions were 78 and 93.7%, respectively. CONCLUSION: Coconut water has a potential to be used in the fabrication of membranes by converting it to nata‐de‐coco and then to cellulose diacetate which gives an added value to its original nature. It is also highly competitive compared to the traditional pulps, by which acetylation decreases the degree of crystallinity of nata‐de‐coco resulting in higher membrane permeability. Copyright © 2007 Society of Chemical Industry     

Mild condition dissolution of high molecular weight cotton cellulose in 1‐butyl‐3‐methylimidazolium acetate/N,N‐dimethylacetamide solvent system

To investigate the effective dissolution of high molecular weight (MW) cellulose macromolecules at ambient conditions, cellulose (DP > 4,000) derived from cotton fiber waste was dissolved in 1‐butyl‐3‐methylimidazolium acetate (BMIMAc)/N,N‐dimethylacetamide (DMAc) solvent in this study. High MW cotton cellulose achieves a solubility between 3% and 5% cellulose concentrations using BMIMAc/DMAc solvent at ambient conditions. Rheological studies showed that all cellulose/solvent solutions displayed a shear thinning behavior. Results from the physical characterization revealed that well‐dissolved cotton cellulose exhibited highly porous structure and the crystalline structure of cotton cellulose was highly disrupted during dissolution and regeneration processes. This study is the first to report on the ability of BMIMAc/DMAc solvent system to dissolve high MW cellulose under ambient conditions, which represents an energy‐saving and environmentally friendly approach. As cellulose used in this study was derived from low quality waste cotton fibers, the potential utilization of such cotton cellulose may create a competitive market for low quality cotton and target advanced applications of cellulose‐based products for green materials and energy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45928.     

Utilization of waste activated bleaching earth containing palm oil in riboflavin production by <Emphasis Type="Italic">Ashbya gossypii</Emphasis>

Waste activated bleaching earth (ABE) discharged by an oil refinery plant, which contained 40% palm oil, was used for riboflavin production by a culture of the filamentous fungus Ashbya gossypii. When 188 g/L waste ABE containing 75 g/L palm oil was added to the culture, 80% of the palm oil was consumed after 4 d, and the riboflavin concentration reached 2.1 g/L after 10 d of culture. This concentration was almost 1.5 times higher than for cultures grown on pure palm oil, in which case only 68% of the palm oil was consumed. Before the culture was initiated, the surface of the waste ABE was smooth and resembled clay that was covered with palm oil. After the culture, the oil content decreased to 8%. The black color of waste ABE gradually faded and turned yellow, with the ABE finally forming a yellow powder. Eighty percent of the riboflavin produced during the culture period was transferred to oil-depleted waste ABE and the waste-oil-depleted ABE had 14 mg of riboflavin/g of oil-depleted waste ABE. The waste ABE containing waste palm oil was suitable for use as a raw material for the production of value-added riboflavin. Thus, this research might provide a good model for the reuse of waste resources containing vegetable oil.     

Biodegradable hot melt adhesive based on partially saponified polyvinyl acetate/cellulose diacetate blend

Recycling the polymer material from the waste has a great advantage in reducing the cost of the biodegradable hot melt adhesive and solving environmental problems. Cellulose diacetate obtained from the acid hydrolysis of discarded cellulose triacetate-based cinematographic films was blended with low molecular weight partially saponified polyvinyl acetate. The degree of substitution of cellulose diacetate and the degree of saponification of partially saponified polyvinyl acetate to obtain the binary blends having excellent compatibility were determined by FTIR and DSC. TGA showed that these blends have sufficient thermal stability for hot melt adhesive applications. The viscoelastic properties of the blends were evaluated by DMA and melt viscosity. The shear strength and the biodegradability of the final hot melt adhesive were examined according to the amount of cellulose diacetate in the blends. The results indicate that adding 20% of cellulose diacetate can reduce the cost of partially saponified polyvinyl acetate -based hot melt adhesive while improving the adhesive strength.     

A sustainable approach to enhance fruit shelf-life: Edible coating from pineapple fruit waste biomass

The quality and commercial value of fruits largely depend on color, texture, appearance, nutritional value, and other factors that cease the growth of the microbes causing food spoilage. Coating with suitable edible material would keep fruits fresh for a considerable time after their harvest till it reaches to the demanding consumers. The nonedible portions (peel, crown) of pineapple are identified as an inexpensive source for the production of such edible coating material. The present work is focused on the extraction and physicochemical analysis of cellulose prepared from waste bio-mass of pineapple fruit. Physicochemical characterization of the cellulose is performed using X-ray diffraction, Fourier-transform infrared spectroscopy and scanning electron microscopy. The extracted cellulose is converted to carboxymethyl cellulose and formulated as a coating film in conjugation with other suitable substances. The formulated coating is applied on banana fruit to check the performance of protection against the natural degradation of the fruit. FTIR analysis of the extracted cellulose has confirmed the removal of lignin and hemicelluloses molecules from the waste biomass of pineapple. X-ray diffraction analysis has shown the crystal size of extracted cellulose was 3.23 nm with 35.62% crystallinity. Degree of substitution (DS) is estimated 0.523 for carboxymethyl cellulose prepared from the extracted cellulose. Application of coating has shown the increment in shelf-life period of banana in comparison with control up to 8 days of storage at ambient condition. This study has demonstrated a sustainable process to transform waste biomass into carboxymethyl cellulose based coating for improving storage capacity of banana fruit.     

Structure and properties of composites of polyethylene or maleated polyethylene and cellulose or cellulose esters

Composites of linear low‐density poly(ethylene‐co‐butene) (PE) or maleated linear low‐density poly (ethylene‐co‐butene) (M‐PE) and cellulose (CEL), cellulose acetate (CA), cellulose acetate propionate (CAP), or cellulose acetate butyrate (CAB) were prepared in an internal laboratory mixer with 20 wt % polysaccharide. The structure and properties of the composites were studied with tensile testing, dynamic mechanical thermal analysis, differential scanning calorimetry, extraction with a selective solvent, Raman spectroscopy, and X‐ray diffraction. Composites prepared with M‐PE presented yield stress and elongation values higher than those of composites prepared with PE, showing the compatibilizer effect of maleic anhydride. Dynamic mechanical thermal analysis performed for M‐PE–CEL, M‐PE–CA, M‐PE–CAP, and M‐PE–CAB composites showed one glass‐transition temperature (T_g) close to that observed for pure M‐PE, and for M‐PE–CAP, another T_g lower than that measured for the polysaccharide was observed, indicating partial mutual solubility. These findings were confirmed by the extraction of one phase with a selective solvent, gravimetry, and Raman spectroscopy. X‐ray diffraction showed that the addition of CEL, CA, CAP, or CAB had no influence on the lattice constants of PE or M‐PE, but the introduction of the reinforcing material increased the amorphous region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:402–411, 2007     

Crystallinity in secondary cellulose esters

Cellulose esters which have a high degree of esterification are readily crystallizable by simple heat treatments. Such esters include cellulose triacetate, cellulose tripropionate, and mixed cellulose triesters. X-ray diffraction analysis shows distinct crystal patterns for these crystalline cellulose esters, and differential thermal analysis shows strong melting peaks. X-ray diffraction analysis of secondary cellulose esters, that is, esters having a substantially lower degree of esterification, shows very diffuse patterns which are only slightly indicative of crystalline structure. Differential thermal analysis, on the other hand, shows strong endothermic peaks which appear to indicate melting of crystalline material. Once melted, secondary cellulose esters cannot be recrystallized easily by simple heat treatments, but it has been found that treatment with certain solvents will induce crystallization. For instance, precipitation of secondary cellulose acetate from acetic acid gave a material which showed two melting peaks by differential thermal analysis, and precipitation from acetone gave a material which showed a single melting peak. A secondary mixed ester, cellulose acetate butyrate, precipitated from acetone had three melting peaks. The coincidence of two of the peak temperatures of this ester with those of the separate triesters of acetic and butyric acids indicated a block rather than a random substitution into the cellulose chain.     

Adsorption and desorption characteristics of zinc on ash particles derived from oil palm waste

Solid waste such as palm fibre and shell produced by the palm oil industry is used by palm oil mills as boiler fuel to produce steam for electricity generation. The ash produced after combustion creates a disposal problem for the palm oil industry. This study explored the potential of oil palm ash as an adsorbent material for removal and recovery of zinc ions from aqueous solutions. The equilibrium uptake of zinc was found to increase with solution pH in the range 3–6, yielding a maximum adsorption capacity of 0.163 mmol g^?1 of ash at a pH of 6. The affinity constant of oil palm ash was found to greatly exceed that of a commercial ion exchange resin, suggesting that oil palm ash may find potential application in treating dilute zinc‐containing waste streams. Four isotherm models were used to fit the constant pH equilibrium isotherms obtained at four different pH values. The entire data set was successfully simulated using two of the isotherm models: a Langmuir model with pH‐dependent parameters and an extended Langmuir–Freundlich model with pH‐independent parameters. The rates of adsorption and desorption for zinc were measured using a stirred‐batch contactor. The contact time required to reach apparent adsorption equilibrium was found to decrease with increasing adsorbent dosage. Both the rate and the extent of zinc desorption were affected by the pH of the desorbing solution. The adsorption and desorption rates were consistent with simple first‐order rate models. © 2002 Society of Chemical Industry     

A chelating cellulose adsorbent for the removal of Cu(II) from aqueous solutions

Regenerated cellulose wood pulp was grafted with the vinyl monomer glycidyl methacrylate (GMA) using ceric ammonium nitrate as initiator and was further fuctionalised with imidazole to produce a novel adsorbent material, cellulose‐g‐GMA‐imidazole. All cellulose, grafted cellulose and functionalized cellulose grafts were physically and chemically characterized using a number of analytical techniques, including elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, and scanning electron microscopy. The cellulose‐g‐GMA material was found to contain 1.75 mmol g^?1 epoxy groups. These epoxy groups permitted introduction of metal binding functionality to produce the cellulose‐g‐GMA‐imidazole final product. Following characterization, a series of adsorption studies were carried out on the cellulose‐g‐GMA‐imidazole to assess its capacity in the removal of Cu²⁺ ions from solution. Cellulose‐g‐GMA‐imidazole sorbent showed an uptake of ～70 mg g^?1 of copper from aqueous solution. The adsorption process is best described by the Langmuir model of adsorption, and the thermodynamics of the process suggest that the binding process is mildly exothermic. The kinetics of the adsorption process indicated that copper uptake occurred within 30 min and that pseudo‐second‐order kinetics best describe the overall process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 2006     

Attainment of cellulose acetate from coir fiber submitted to pretreatment with IL n-butylammonium acetate

Cellulose acetate was obtained from the coir fiber submitted to the treatment with the IL. The coir fiber was initially subjected to treatment with the n-butylammonium acetate IL (CFIL) and subsequent bleaching (CFILB). By analyzing the CFILB, it was possible to observe a delignification of 6.10% in relation to the natural material and an 8.1% increase in the concentration of cellulose. The results from SEM, XRD, and FTIR-ART confirm the modifications in the fiber. After characterizing the treated coir fiber and obtaining the cellulose acetate, analyses by NMR confirmed its regeneration with a degree of substitution at 2.92. FTIR analyses corroborate with the obtained data, verifying the presence of the main adsorption bands. The XRD analysis of cellulose acetate shows peaks at 8.5° regarding the randomness after the acetylation of cellulose, as well as peaks between 18° and 22.5° regarding the packing of carbon atoms due to the Van der Waals forces, which confirm the production of cellulose acetate. The thermal analysis shows that decomposition events occurred in two stages, indicating the thermal decomposition of the remaining cellulose, which did not undergo acetylation, and attribution to its thermal degradation.

     

Production of recycled cellulose fibers from waste paper via ultrasonic wave processing

Recycling waste paper can be considered as a means to displace the use of natural cellulose fibers applied in building materials, because it is composed mostly of cellulose. The water absorption and special surface area of cellulose fibers are the key properties for their use in building materials. The objective of this article was to study the production of recycled cellulose fibers from waste paper using ultrasonic wave processing. The physical and chemical properties of recycled cellulose fibers, such as water absorption, specific surface area and pore characteristics, etc., were investigated with various testing methods. The results indicated that the ultrasonic cavitation effect was feasible for the preparation of the secondary fibers. When the ultrasonic treatment time lasted for 10 min, the water absorptions of both newsprint fibers and kraft fibers increased significantly and reached the highest values of 12.5 g/g and 11.2 g/g, respectively, which were nearly two times than that of fibers without ultrasonic treatment. With a pretreatment of 20 min, the average length and fineness of recycled cellulose fibers decreased by 4% and 25%, respectively, and the length‐diameter ratio of the recycled cellulose fibers was 1.28 times than that of the untreated fibers, which greatly increased the special surface area of the recycled cellulose fibers. This work also determined that NaOH was useful to improve the physical properties of the recycled cellulose fibers. Because the recycled cellulose fibers after processing, fulfilled several technical indexes, they can be considered as a filling material for used in cement‐based materials. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41962.     

Synthesis of Transesterified Palm Olein‐Based Polyol and Rigid Polyurethanes from this Polyol

Transesterification of palm olein with glycerol can increase the functionality by introducing additional hydroxyl groups to the triglyceride structure, an advantage compared to using palm olein directly as feedstock for producing palm‐based polyol. The objective of this study was to synthesize transesterified palm olein‐based polyol via a three‐step reaction: (1) transesterification of palm olein, (2) epoxidation and (3) epoxide ring opening. Transesterification of palm olein yielded approximately 78 % monoglyceride and has an hydroxyl value of approximately 164 mg KOH g^?1. The effect of formic acid and hydrogen peroxide concentrations on the epoxidation reaction was studied. The relationships between epoxide ring‐opening reaction time and residual oxirane oxygen content and hydroxyl value were monitored. The synthesized transesterified palm olein‐based polyol has hydroxyl value between 300 and 330 mg KOH g^?1 and average molecular weight between 1,000 and 1,100 Da. On the basis of the hydroxyl value and average molecular weight of the polyol, the transesterified palm olein‐based polyol is suitable for producing rigid polyurethane foam, which can be designed to exhibit desirable properties. Rigid polyurethane foams were synthesized by substituting a portion of petroleum‐based polyol with the transesterified palm olein‐based polyol. It was observed that by increasing the amount of transesterified palm olein‐based polyol, the core density and compressive strength were reduced but at the same time the insulation properties of the rigid polyurethane foam were improved.     

Structure and properties of novel regenerated cellulose films prepared from cornhusk cellulose in room temperature ionic liquids

Cornhusk cellulose was regenerated using the ionic liquids viz., 1‐allyl‐3‐methylimidazolium chloride (AmimCl) and 1‐ethyl‐3‐methylimidazolium acetate (EmimAc). The cast cellulose films were characterized by FTIR, WAXD and SEM techniques. Their mechanical properties were also studied. These studies indicated that AmimCl and EmimAc are good solvents for the regeneration of cornhusk cellulose. The regenerated cornhusk cellulose (RCC) was found to be cellulose (II) with dense structure. The films cast from AmimCl exhibited good mechanical properties; the tensile modulus and strength were as high as 6 GPa and 120 MPa respectively, whereas these values for those films cast using EmimAc were found to be 4.1 GPa and 47 MPa respectively. Further, it was observed that after regeneration, the solvents could be effectively recycled. Thus a novel nonpolluting process of forming RCC films from agricultural waste was developed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

聚乙二醇/纤维素相变材料的制备及性能表征

以微晶纤维素（MCC）为原料，制备纤维素海绵（Cell），并以其作为基体，通过物理共混的方法与聚乙二醇（PEG）PEG-6000进行复合，制备聚乙二醇/纤维素相变材料（PCMs），研究了PCMs的结构与相变储能性能。实验结果表明：PCMs中PEG的质量分数可以达到90.77%，且相变过程中不会发生液体泄漏的问题。FT-IR分析表明纤维素基体和PEG之间存在明显的氢键作用，无新化合物产生。XRD分析结果表明：与纯PEG-6000相比，纤维素基体的加入不会改变PEG的结晶形态，但会降低PEG的结晶度。DSC结果表明，PCMs的熔融焓（ΔH_f）随着PCMs中PEG质量分数的增加而增大，ΔH_f最高可达146.88J/g（PCM₅），但均小于纯的PEG（179.09J/g）；PCMs的结晶焓（ΔH_c）随着PCMs中PEG质量分数的增加而降低，ΔH_c的绝对值最高可达137.81J/g。TG分析表明，当环境温度小于250℃时，PCMs的热稳定性较好。     

Preparation of diacylglycerol‐enriched palm olein by phospholipase A1‐catalyzed partial hydrolysis

Partial hydrolysis of palm olein catalyzed by phospholipase A₁ (Lecitase Ultra) in a solvent‐free system was carried out to produce diacylglycerol (DAG)‐enriched palm olein (DEPO). Four reaction parameters, namely, reaction time (2–10 h), water content (20–60 wt‐% of the oil mass), enzyme load (10–50 U/g of the oil mass), and reaction temperature (30–60 °C), were investigated. The optimal conditions for partial hydrolysis of palm olein catalyzed by Lecitase Ultra were obtained by an orthogonal experiment as follows: 45 °C reaction temperature, 44 wt‐% water content, 8 h reaction time, and an enzyme load of 34 U/g. The upper oil layer of the reaction mixture with an acid value of 54.26 ± 0.86 mg KOH/g was first molecularly distilled at 150 °C to yield a DEPO with 35.51 wt‐% of DAG. The DEPO was distilled again at 250 °C to obtain a DAG oil with 74.52 wt‐% of DAG. The composition of the acylglycerols of palm olein and the DEPO were analyzed and identified by high‐performance liquid chromatography (HPLC) and HPLC/electrospray ionization/mass spectrometry. The released fatty acids from the partial hydrolysis of palm olein catalyzed by phospholipase A₁ showed a higher saturated fatty acid content than that of the raw material.     

Production and utilization of palm fatty acid distillate (PFAD)

PFAD (palm fatty acid distillate) is a by‐product of physical refining of crude palm oil products and is composed of free fatty acids (81.7%), glycerides (14.4%), squalene (0.8%), vitamin E (0.5%), sterols (0.4%) and other substances (2.2%). PFAD is used in the animal feed and laundry soap industries as well as a raw material for the oleochemicals industry. Vitamin E, squalene and phytosterols are value‐added products which could be extracted from PFAD and are of potential value for the nutraceutical and cosmetic industries.     

The effect of plasticizer and cellulose nanowhisker content on the dispersion and properties of cellulose acetate butyrate nanocomposites

We studied the effects of plasticizer and cellulose nanowhisker content on the dispersion and properties of cellulose acetate butyrate (CAB)‐based bionanocomposites. The cellulose nanowhiskers in an aqueous medium were solvent‐exchanged to nonaqueous polar solvent (acetone) and used for nanocomposite processing by solution casting. The plasticized and unplasticized nanocomposites with 5 and 10 wt % cellulose nanowhisker content were prepared. Atomic force microscopy indicated nanoscale dispersion of whiskers in the CAB matrix. The dynamic mechanical analysis showed an increase in storage modulus with addition of cellulose nanowhiskers, especially above the glassy‐rubbery transition region. Thermogravimetric analysis showed an improvement in thermal stability with increased whisker content for both unplasticized and plasticized nanocomposites. The plasticized nanocomposites showed better transparency than the unplasticized composites, indicating a better dispersion of cellulose nanowhiskers in CAB, in the presence of a plasticizer. The dynamic mechanical properties and thermal stability increased, whereas transparency decreased with increased CNW content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Characterization of empty fruit bunch for microwave-assisted pyrolysis

Agricultural waste such as oil palm empty fruit bunch (EFB) is of environmental concern to Malaysia as one of the world’s largest oil palm producers. Pyrolysis can be used to treat biomass waste due to its flexibility in producing solid, liquid and gas products. This study attempts to characterize EFB for pyrolysis using microwaves as an alternative heating source. EFB taken from a local oil palm mill was subjected to fuel, chemical and dielectric property analysis. The findings revealed that high moisture and 47% oxygen gave low calorific value of 16 MJ/kg. Notably, high water content is an advantage in microwave heating as water is a good microwave absorber, which results in fast drying. Further, a high volatile content at 70% gave the EFB an advantage of high reactivity. A moderate potassium content of 12.8% could also positively affect microwave absorption. The dielectric properties of EFB were observed to be proportional to the moisture content. Furthermore, the microwave penetration depth was found highest at 20% moisture, i.e. 3.5 cm. However, low values of both dielectric constant and loss of dried EFBs would require the addition of microwave absorbers for pyrolysis reaction. The fuel and chemical characteristics of EFB were found comparable to other biomasses, which indicated a good candidate for microwave pyrolysis treatment.     

Barrier properties of poly(ethylene‐co‐vinyl acetate)/cellulose composite membranes

Poly(ethylene‐co‐vinyl acetate) (EVA)/cellulose composite membranes were prepared and their vapor permeation characteristics were studied. Two types of EVA [having vinyl acetate contents of 18% (EVA18) and of 40% (EVA40), respectively] were used for the composite fabrication. Cellulose, isolated from banana waste fibers, was used as the filler. It was observed that the EVA40 composites were more permeating than were the EVA18 composites. This observation is explained on the basis of more amorphous nature of EVA40 as compared to EVA18. The extent of vapor permeation decreased with increase in the cellulose content in the composites. The presence of voids in the polymer membranes that were designed to possess controlled behavior for the permeation was confirmed using scanning electron microscopic images to complement the observations made during the permeation studies. The influence of molecular weight, molar size, and polarity of the penetrants, on the permeation process, was also considered. The permeability of the membrane samples was calculated and the values obtained were compared with the theoretical values provided by using the modified Neilson permeability equation. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Office waste paper as cellulose nanocrystal source

Cellulose nanocrystals (CNC) are isolated from office waste paper using an alkali solution and a subsequent acid hydrolysis process. The Fourier transform infrared spectroscopy and X‐ray diffraction (XRD) results demonstrate that ink and fillers used in the papermaking industry are almost totally removed after alkali treatments. The XRD results show that CNCs obtained after 2 wt % NaOH solution treatment and a subsequent hydrolysis process exhibit only a cellulose I crystalline structure, and the crystallinity index value increases around 42% with respect to initial office waste paper. Nevertheless, CNCs obtained after 7.5 wt % NaOH solution treatment and a subsequent acid hydrolysis process show a mixture of cellulose I and cellulose II polymorphs. The thermal analysis shows that the CNCs obtained after 7.5 wt % NaOH solution treatment and a subsequent acid hydrolysis process are thermally less stable than other samples, suggesting that the cellulose chains could depolymerize into low molecular weight sugar compounds. Even though the atomic force microscopy images confirm the presence of CNCs, the optical images show that some cellulose microfibers still maintain their structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45257.