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Valorisation of glycerol through catalytic conversion conducted using KOH base catalysts with a mass ratio of KOH/glycerol of 0.08 (w/w) was carried out at temperature variations of 230 °C and 300 °C with feedstock variations of pure glycerol (98%) and crude glycerol with a total reaction time of 2 hours. Crude glycerol was obtained from the by-product of biodiesel transesterification from crude palm oil (CPO) using a KOH catalyst of 1% by weight of crude palm oil with variations in CPO:methanol such as 1:3, 1:6, and 2:1, which were performed at 60 °C for 4 hours at stirring speeds of 400 rpm. The largest percentage of crude glycerol conversion was obtained from the variation CPO: methanol (2:1) of 30.67%. The GC-MS characterization of glycerol catalytic conversion products revealed that the highest yield percentage is on the variation of pure glycerol feedstock at 230 °C, with the long-chain hydrocarbon fraction in the form of stearic acid compounds having the highest abundance percentage (abundance percentage of 26.54%). Catalyticconversion of pure glycerol feedstock variations at a reaction temperature of 300 °C resulted in formic acid (abundance percentage of 24.68%) with the greatest abundance and oxalic acid (abundance percentage of 2.28%). Meanwhile, the feedstock variation of crude glycerol produced 2-propenoic acid (abundance percentage of 5.04%) and acetone (abundance percentage of 2.84%), as well as hexadecanoic acid with the largest abundance percentage (32.04%). These findings demonstrated that catalytic glycerol conversion with KOH catalysts produced compounds with a wide range of industrial applications. [ABSTRACT FROM AUTHOR]

Acrylic acid (AA) monomer is an important chemical for the acrylic polymer industry. Wastewater discharged from manufacturing poly-acrylic acid contains a certain amount of unreacted AA, making the wastewater acidic. When discharged directly into sewage, this acidic wastewater exhibits a very high chemical oxygen demand (COD) value. Furthermore, due to the toxicity of AA to aquatic organisms, the AA-containing wastewater needed to be treated accordingly, complying with environmental standards before being discharged into the environment. We prepared two types of industrial wastewater containing AA from wastewater of a commercial poly-acrylic acid plant, and they were treated using coagulation, flocculation and adsorption methods on a laboratory scale with a maximum capacity of 50 L in batch mode. We scaled up the processes to treat industrial wastewater on a mini-pilot scale with a maximum capacity of 1,000 L in batch mode. The experimental results showed that the established mini-pilot scale waste treatment plant had produced an effective waste treatment by conducting coagulation, flocculation, and adsorption process for the removal of acrylic acid from the industrial wastewater, from 8,230 mg/L of COD value to less than 83 mg/L, with over 99.0% removal of AA from the industrial waste. [ABSTRACT FROM AUTHOR]

This research emphasizes the application of bio-based nanosilica, which was obtained from rice husk, for the purpose of improving the characteristics of discarded empty fruit bunch (EFB) fibers. One of the lignocellulose biomass byproducts from the palm oil industry is EFB fibre, which is typically used as a fuel source in boilers. Lightweight, nonabrasive, and biodegradable characteristics of EFB fibres make them ideal for usage as a reinforcing agent in composite and plastic applications. Unfortunately, the hydrophilic nature of EFB fibre results in weak interfaces because EFB surface and polymer matrix exhibit low interfacial adhesion, which may negatively affect the mechanical characteristics. To remedy this situation, the EFB fibre will be modified via environmental friendly ultrasound assisted alkaline and acrylic acid treatment. The bio-based nanosilica will be introduced during the acrylic acid treatment, in which can further improve the thermo-mechanical properties and control the biodegradability of the composite. The treated EFB fiber was characterized with Scanning Electron Microscopy (SEM), Fourier-Transform Infrared Spectroscopy (FTIR), and tensile testing. Findings reveal that the impurities on the surface of EFB fibre were washed away after the treatment and impregnation of nanosilica on the surface of EFB fibre were visualised. The results obtained from FTIR confirm that the hemicellulose has been eliminated within the range of 2900-1700 cm−1. Tensile test demonstrates that small amount of bio-based nanosilica improves the mechanical properties by 91.11% as compared to raw EFB fibre. [ABSTRACT FROM AUTHOR]

Several natural and synthetic radionuclides are found in water at various concentrations, including uranium. Uranium ions in water are an important problem because of the chemical and radiological toxicity effects, which will affect people's health. Hemp cellulose-based adsorbent is expected to be able to adsorb uranium ions from wastewater. In this study, hemp cellulose was modified by irradiation simultaneous grafting method using acrylic acid as a monomer and gamma rays as the reaction initiator. The aim of this study is to obtain the irradiation grafted hemp cellulose-based adsorbent for adsorbing U(VI) ions. The adsorbent sample was characterized using FTIR, XRD, and SEM. Characterization using FTIR showed the occurrence of the acrylic acid grafted onto the cellulose, and characterization by SEM showed a change in the diameter of the grafted sample. While the XRD showed the crystallinity of the grafted sample decreased. The analysis of the percentage of removal efficiency shows that 3 hours of contact time and a pH solution of 4 are the best conditions to reach the highest adsorption of U(VI) ions. Meanwhile, in the equilibrium isotherm study, the adsorption data fitted well with the Freundlich isotherm model. This makes hemp cellulose-g-acrylic acid adsorbent the potential prospect for treating wastewater containing uranium ions. [ABSTRACT FROM AUTHOR]

In this study, hydrogel of "Carrageenan with carboxy methyl cellulose-grafting-poly acrylic acid (CG/CMC-g-P(AA))" was used as the adsorbent for the removal of metformin hydrochloride MFC and hydroxychloroquine sulfate HCQ from aqueous solutions. In order to investigate the structure and morphology of the hydrogel, an FTIR as well as a field emission scanning electron microscope were utilized. The effect of equilibrium time was investigated, and it was determined that the adsorption of MFC and HCQ onto CG/CMC-g(AA) hydrogel reached equilibrium after 120 minutes. The removal percentage of metformin hydrochloride (MFC) and hydroxychloroquine sulfate (HCQ) by CG/CMC-g-P(AA) hydrogel were found to be 89.7% and 97.9%, at the same order. The adsorption kinetic result was well fitted to model second order, The data found that rate constants of the second order (MFC-G/CMC-g-P(AA)) system is much higher than that of (HCQ-CG/CMC-g-P(AA)) hydrogel. [ABSTRACT FROM AUTHOR]

This study used sodium alginate-g-poly (acrylic acid-maleic acid)/TiO2 nanocomposite hydrogel as an effective adsorbent surface removal crystal violet (CV) from the solution. The nanocomposite structure and morphology were studied using (FE-SEM), (TEM), (EDX), and (AFM). Study the different effect parameters like the effect of solution pH, the effect of concentration salt, and the effect of solution temperature. The result found the amount of CV dye adsorption is little at pH=3 and then gradually increases until it reaches a peak at (pH=6). The amount of CV dye adsorption on the adsorbent surface decreases with increased salt concentration. Adsorption of (SA-g-(PAA-MA)/TiO2) hydrogel increased with increased solution pH, and the most successful result was pH=6, and the adsorption efficiency decreased with increased ionic strength. Thermodynamic parameters at several temperatures (15, 20, 25, and 30 °C) revealed that the adsorption process was spontaneous. Thermodynamic parameter for the adsorption process of CV dye, that negative value of the enthalpy indicates that the CV dye adsorption process is exothermic. [ABSTRACT FROM AUTHOR]

Carboxymethylcellulose, sodium alginate and acrylic acid as monomers are polymerized by free radical polymerization as a cross-linker, and ferric chloride (III), and iron sulfate were used. In contrast, potassium persulfate was used as an initiator. Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy were used to characterize the generated GO(CMC-SA-AAc) hydrogel composite. The synthesized hydrogels were utilized as adsorbents to remove the Azure B dye from an aqueous solution. The synthesized adsorbents have a very high adsorption capacity and great effectiveness in removing Azure B. According to the results, the adsorption method was discovered to be the following pseudo-second-order kinetics, and the adsorption equilibrium time was obtained in 60 minutes. [ABSTRACT FROM AUTHOR]

The superabsorbent hydrogel is a hydrophilic polymer with high water absorption capability. Superabsorbent hydrogels have become a potential material for some applications e.g. waste treatment, agriculture media, and health care applications. The chitosan-based superabsorbent hydrogel was synthesized with the variation of acrylic acid concentrations from 0% to 2% (v/v). The effects of acrylic acid on the characteristics of superabsorbent were studied in this research. Superabsorbent hydrogels were successfully synthesized from chitosan and acrylic acid using glutaraldehyde as a crosslinker agent and potassium persulfate as an initiator. The results show that adding acrylic acid increased the tensile strength and swelling ratio but decreased the hydrogel's gel fractions and elongation percentage. The highest swelling ratio (608%) was obtained at a 2% concentration of acrylic acid. [ABSTRACT FROM AUTHOR]

Corrosion of steel reinforcements in concrete constructions is a big topic for the building industry. Polymeric materials are a possible alternative due to their ability to withstand corrosion. To replace steel reinforcements, fibers with high mechanical properties and a good bonding ability between fiber and concrete are needed. Today different approaches for concrete reinforcement by polymer fibers have been investigated. The bonding ability of the fibers can be increased by mechanical anchoring, e.g. crimped or embossed fibers, as well as by a chemical bonding between concrete and fiber surface. To realize the requirements of high mechanical properties and a good bonding behavior, a fiber that is drawn from a co-extruded filament shall be produced and tested. The filament owns an innovative core-shell-structure. The core maintains the fiber-stiffness and the tensile strength while the shell allows using another material to affect the bonding behavior of the fiber. This study shows the usage of fibers with differing shell materials to examine their influence on the mechanical properties of the fiber in total and the adhesion abilities to concrete. As core material, an unfilled polypropylene (PP) is used. The shell materials are varied using different polymers e.g. polypropylene or ethylene acrylic acid copolymer, as well as two PP based compounds filled with wood particles and calcium carbonate blended with a maleic anhydride based coupling agent. The mechanical properties of the fibers are tested by fiber tensile tests to compare the younǵs modulus and the tensile strength. The influence of the shell phase on the bonding ability to concrete is evaluated by the interfacial shear strength calculated from single fiber pull-out tests. Microscopy is used to interpret changes before and after pull-out. The results depict incredible positive effects and allow new insights in possible materials for fiber reinforced concrete constructions. [ABSTRACT FROM AUTHOR]

One of the methods to increase agricultural yields is by intensification through fertilization. The most widely used fertilizers as primary nutrient source are chemical fertilizers from simple chemical compounds that are easily and readily soluble in water. The conventional fertilization process is done by spreading fertilizer on the soil, the fertilizer will dissolve in moisture in the soil and can be absorbed by plants. However, from the fertilizer moisture solubilized in the soil, not all of it can be absorbed readily by plants, so that the dissolved phosphate fertilizer in the soil that is not absorbed by plants can cause environmental pollution. To overcome this environmental problem, this paper describes the release of phosphate fertilizer to be controlled using a hydrogel composite matrix. The hydrogel composite matrix was synthesized from arrowroot starch-g-poly(acrylic acid-co-acrylamide)/zeolite through a graft polymerization process with the addition of fertilizers at various concentrations. The hydrogel composite showed a shift in the infrared (IR) spectrum which indicated that the acrylic acid and acrylamide monomers had been grafted onto the arrowroot starch chain. Zeolites and fertilizers interact with the hydrogel matrix during polymerization. The water absorption of the hydrogel composite decreased when the zeolite mineral concentration in the composite was increased. The water absorption capacity of the hydrogel composite and phosphate release were increased in the buffer solution from pH 5 to pH 9. The amount of phosphate released in all buffer solutions would increase if the concentration of fertilizer added in the composite matrix was increased. [ABSTRACT FROM AUTHOR]

The cellulose-g-acrylic acid (C-g-AA) and its crosslinked form (crosslinked C-g-AA) were prepared from rice straw cellulose using radiation technique. Acrylic acid and N, N'-methylene bisacrylamide were used as a functional monomer and a bifunctional crosslinking agent, respectively. The effect of radiation modification on rice straw cellulose was studied and compared to each other. The modification of rice straw cellulose was confirmed by the appearance of new carbonyl vibration in the infrared spectra. The field emission scanning electron microscope images revealed that the cellulose possesses a microfibril shape which getting rough with the grafting and crosslinking process. Moreover, the X-ray diffraction pattern exhibited a slight change in the crystallinity index due to the modification of the cellulose structure. As a result, the physical and chemical properties of modified cellulose are better than those for pristine cellulose. Thermogravimetric analysis revealed that the thermal resistance is in the following order: crosslinked C-g-AA>C-g-AA > cellulose. This result agreed well with the acid and solvent resistance and ion exchange capacity. In addition, the modified cellulose was effectively used for copper ion adsorbent, with an adsorption capacity of 16.5 mg/g. [ABSTRACT FROM AUTHOR]

The paper presents information on the effect of polymer modifiers on the variation in production conditions and the main operational properties of filled acrylic systems, cured by the mechanism of radical polymerization. By preliminary injection and dissolution in the monomeric phase of modifiers - suspension polystyrene and its copolymers (with methyl methacrylate, methyl methacrylate and acrylonitrile) acrylic compounds were obtained with acceptable indicators of technological viscosity and the ability to adjust its viability under normal conditions. The combination of manufacturability and realizable physical characteristics of modified acrylic polymers made it possible to carry out on their basis the directed development of filled adhesive compositions with improved adhesion characteristics. According to the experimental data of relaxation spectroscopy and the calculated values of linear dilatometry, it was evaluated that when a filler is injected into the acrylic system, a supramolecular structure with a characteristic surface layer is formed, which makes a significant contribution to the variation in the macrophysical characteristics of the material (an increase in the dynamic shear modulus from 1.6 to 2.4 GPa). Therefore, mobilization to preserve the resource of the adhesive contact (not less than 18 MPa) with permissible amounts of filler (from 10 to 30 mass parts in polyacrylate) and thicknesses of the adhesive layer occurs due to the total contribution of the dispersed phase to the strengthening of the polymer. The superposition of various factors, and first of all, a decrease in the density of the polymer phase in the filled system, contributes to a slight drop in the adhesion strength of acrylic glue to a metal substrate, which in general should provide an acceptable degree of reliability of adhesive building constructions. [ABSTRACT FROM AUTHOR]

In the current study, production a novel nano co-polymer via reaction phthalic anhydride with glycerol, as it was diagnosed through FTIR, 1HMNR, AFM, XRD and TEM techniques. Three distinct moles of acrylic acid monomer (0.15, 0.25, 0.35 mol), were implemented to the synthesis nano co-polymer to produce three kinds of polymers, which vary in the monomer ratio of acrylic acids. The potential for glutathione protein loading at concentrations (0.3, 0.4, 0.5, 0.6 and 0.7 g / mol) to a sample of nano polymers prepared at a constant temperature of 310 K and in acidic pH solutions (2.2 and 8.0) at different hours was studied, After that, release the protein of glutathione at consistent temperatures of 310 and in solutions with acidic functions pH (2.2 and 8.0) by various hours ,then determining the quantity of protein released utilizing UV.-Vis. Technique. According to the results ,the loading and release of proteins was greater in the primary medium (pH=8.0) than in the acidic medium (pH=2.2), which implies that the copolymer is a selective community. And sensitive in these two mediums. [ABSTRACT FROM AUTHOR]

Demulsifiers are very important additives in the oil industry due to their crucial role in solving the water – in – oil emulsions problem. Inventing new demulsifiers have gained a lot of researchers' attention; factors like efficiency, versatility, cost and safety were taken into consideration when preparing new demulsifiers.Recycling industrial waste materials has many great benefits economically and environmentally and in this research methyl methacrylate has been prepared from the depolymerization of Plexiglas wastes, Plexiglas is the trade name for poly methyl methacrylate sheets. The (DM) which refers to depolymerized methyl methacrylate was purified and tested by using many methods such as boiling point, infrared spectroscopy; refractive index and gas chromatography GC to determine its purity. Then the depolymerized methyl methacrylate was used in an oil demulsifier mixture in treating water in oil emulsions in crude oil and HFO which refers to heavy fuel oil. The crude oil samples were taken from Al – Hilla 2 power plant while the HFO samples were taken from the South Baghdad 2 power plant. In this research, the spectr oil test had been used after treating the crude oil to determine the demulsification process by measuring the Na and K salts concentration.The purity of the DM was 96.4% according to the GC test. The spectroil results showed that when the DM was used in a demulsifier mixture with water miscible chemicals and chemicals with sufficient solubilities like acrylic acid and butyl acrylate the best demulsification results were obtained (when using 30% wash water) for both crude oil and heavy fuel oil (HFO) with a demulsifier concentration ranging from (200 – 300) ppm. [ABSTRACT FROM AUTHOR]

The modification of natural polymer such as Chitosan (CH) is interest in this work because it would not change the important structure of the (CH) skeleton; maintaining the original physicochemical and biochemical properties to bring new or improved properties. The polymer was prepared by modifying the structure of (CH) with vinyl monomer such as acrylic acid (CH-g-acrylic acid) using a free radical initiator ceric ammonium nitrate; then the graft copolymer was relieved with Amoxilline (AM) through amino group. This work entails a controlled delivery (CD) over a long time due to its digestive nature. The synthesized copolymer was subjected to various analytical methods such as (FTIR); (UV) and (1H- NMR) ; spectroscopy; thermal study such as TGA and DSC were analysis. The physical properties of the prepared polymer were tested. Our results show that sustain release (SR) is tested at 37 °C in an in vitro study and drug release (DR) was compared through few days. The hydrolysis rate was observed that in basic was higher than in acid medium. It was concluded that several compensations of continued release by a modified drug and in vivo presentation was shown to be sustained release(SR) as talented for those infected with bacteria and wounds. [ABSTRACT FROM AUTHOR]

To date, there is an increase in the incidence of skin and subcutaneous tissue diseases, despite the variety of treatment methods. One of the promising class of biomaterials for the treatment of skin diseases can be coatings based on hydrogels. The purpose of this study was to obtain collagen-acrylic hydrogels with various technological parameters (varying the synthesis temperature and the degree of neutralization of acrylic acid) with the specified properties by radical polymerization. The chemical structure of the polymer gel was studied by infrared spectroscopy and thermogravimetric analysis. It was determined that samples with a neutralization degree of 0.8 have the highest sorption characteristics (obtained at 30°C) and thermal stability (obtained at 40°C). [ABSTRACT FROM AUTHOR]

Studies on radiation grafting of a hydrophilic monomer onto chitin for ion exchange applications were Chitin has been increased attention for its use, such as ion exchange. They are utilized scarcely because of problems with low solubility, hydrophobicity, and reactivity. Irradiation graft copolymerization induced by irradiation is one of the methods for chitin modification to improve its properties such as hydrophobicity and reactivity. This research aims to increase the ability of chitin as ion exchange for the heavy metal adsorbent. The hydrophilic monomers used were acrylic acid and acrylamide. In the present research, the pre-radiation method was used. The irradiation of the sample was carried out in the Co-60 gamma ray irradiation source at room temperature. The monomers solutions acrylic acid or acrylamide than introduce into irradiated chitin, and the graft polymerization was done in an inner condition. The grafting presentation has been determined as a variation of monomer concentration and temperature as a function of the reaction time. The grafted chitin obtained was washing and dried in a vacuum, and the percentage of grafting was measured by the gravimetric method. Measuring the capacity of adsorption of grafted chitin to Cr, Cu, and Hg metal ion was determined by using AAS and CV AAS. The result shows that using acrylamide gives a percentage of grafting higher compare with acrylic acid. The FTIR spectrum demonstrates the presence of monomer grafted onto chitin with the appearance of the carbonyl functional group. Chitin grafted with acrylic acid gives a higher rate of adsorption of metal ion Cr, Cu, and Hg compare grafted with acrylamide. The highest percentage of adsorption is for metal ion Hg. It was found 294 mg/g for chit-g-Aac and 257 mg/g for Chit-g-Aam., [ABSTRACT FROM AUTHOR]

The goal of this study was to investigate the effect of surface treatment on rice husk reinforced recycled high density polyethylene (rHDPE) composites. Three types of surface treatments on rice husk were carried out which were maleated treatment, alkali treatment and acrylic acid treatment. Water absorption test was examined in distilled water. It showed that the lower the loading of rice husk, the lower the water absorption percentage. Maleated treatment on rice husk reinforced rHDPE has the highest resistance of water absorption tendency. Scanning electron microscope analysis of the composites showed that the lower the rice husk loading, the better the interfacial bonding of the composites. Maleated treatment of rice husk also showed that there is no gaps formed in the structure. [ABSTRACT FROM AUTHOR]

In this study, a fresh method with high sensitivity, low cost and high stability has been developed by using a molecularly impressed polymer (MIP). A functional monomers namely, acrylic acid (AA) and acrylamide-2methyl propane sulphonic acid (AMPS) were also used. Appropriate cross-linking and CLO template were used to generate monolithic solid-phase micro-extraction (SPME) fiber. A non-imprinted polymer (NIP) was also developed without selective binding places. The firmness, stability and durability of the manufactured fiber give it vital place in SPME. Samples were obtained from clopidogrel were measured by using UV-vis, Electron Microscopy Scanning (SEM) and FTIR. The relative standard deviation %RSD and recovery test %R for three drug based on triplicate analysis of samples have been determined. In general, good levels of %RSD and %R were obtained for Instruments with perfect range of 1.20-2.61% RSD and 96.63-99.71 %R, respectively. [ABSTRACT FROM AUTHOR]

New silver nanocomposites (AgNCs) based on copolymers of N-methyl-2-azanorbornene-5 (MAN), N-benzyl-2-azanorbornene-5 (BAN), N-allyl-2-azanorbornene-5 (AAN) and N-(2-azanorbornene-5)methylacetate (MAAN) with acrylic acid (AA) have been developed. The reduction of silver ions into silver nanoparticles was achieved using NaBH4 as a reducing agent. UV-spectroscopy and scanning electron microscopy techniques were used to characterize the formation of silver nanoparticles in copolymers. The average silver particle size ranged from 15 to 52 nm, with the corresponding UV-vis absorption peak position at 400-412 nm. The AgNCs have exhibited significant cytotoxic activity towards melanoma line cells. [ABSTRACT FROM AUTHOR]

Fertilization on plants is normally performed by spreading fertilizer directly to the soil, which can pollute the environment since not all the fertilizers are instantaneously absorbed by the plants. One method being developed to overcome this problem is by using a matrix for controlled release fertilizers (CRF). CRF that is commonly used is hydrogel composite based. In this study, hydrogel composite was synthesized from local arrowroot starch with co-monomer (acrylic acid-co-acrylamide), zeolite, and urea-KH2PO4 through a radical polymerization process. The hydrogel and hydrogel composite were characterized by using FT-IR spectroscopy, SEM, and EDS. The swelling capabilities test and release rate of nitrogen, potassium, and phosphorus were measured at buffered pH of 5 and 7, and in distilled water. The results of FT-IR, SEM, and EDS show that zeolite and fertilizers were dispersed evenly in the hydrogel composite. Results from the swelling capabilities test showed the highest value when performed in distilled water, followed by results in pH 5, and pH 7. Measuring the concentration of nitrogen, phosphorus, and potassium released in the buffer pH 5, pH 7 and in water over a period of 0 to 100 hours shows that they are released gradually. Therefore, hydrogel composites synthesized from local arrowroot starch, monomers (acrylic-acrylamide), zeolite, and urea-KH2PO4 show promising results as controlled release fertilizers of Nitrogen, Phosphorous and Potassium. [ABSTRACT FROM AUTHOR]

Latex has mechanical properties that indubitably suits the requirement of the vehicle tire, which is highly elastic modulus. However, elastic modulus itself is a downside to tire; it affects the tire traction, which is also an important aspect of tire performance. To resolve this issue, latex needs to be crosslinked or grafted to a low elastic modulus; in this case, starch. Contact Glow Discharge Electrolysis (CGDE) is a potential method to massively graft polymers with different chemical and physical properties, such as a latex-starch hybrid. Using CGDE, the problem of reacting reactants that were not intermingled, due to differences in polarity, can be forced to bind through a radical reaction mechanism. Based on the previous research, the optimal plasma position is in the cathode, which produces more hydrogen radicals than anode; reasonably, this reaction is mostly affected by hydrogen radicals. In this research, experiments will be mainly focused on the addition of methanol, a hydrogen radicals additive. I-V characterization was also done to the solution with the plasma position in the anode. The current starts to decrease at 200 V and plasma starts to stabilize at 250 V. After data is analyzed, the results of methanol addition are quite contrary. After adding methanol with a concentration of 5%v, 10%v and 15%v, the latex-starch hybrid production is decreased by 7.47%, 8.68%, and 9.01% respectively. The experimental results show that CGDE with methanol solution is not suitable for latex-starch hybrid synthesis and further optimization will need to be done. [ABSTRACT FROM AUTHOR]

Carbon dioxide is one of the main gases that cause greenhouse gas emissions in the atmosphere. One way to reduce gas emissions is to convert CO2 and produce high-value products. Because it is atmospherically inert, catalyst assists CO2 to react with other compounds. In this research, hierarchical ZSM-5 was prepared from natural minerals as sources, which is Bayat zeolite and Bangka kaolin, then impregnated with bimetal Ni-Zn as a catalyst to convert CO2 in the presence of ethyne to produce acrylic acid. Natural mineral-based hierarchical ZSM-5 was prepared using double template method, with TPAOH as a primary template that directed to MFI framework and PDDA-M as a secondary template that directed mesoporous structure. Impregnation of nickel (Ni) and zinc (Zn) bimetallic was conducted by co-impregnation method followed by reduction with H2 gas flow. Material characterization such as FTIR, XRD, XRF, SAA, and SEM-EDX were conducted on the catalyst. FTIR analysis shows that there has been a complete decomposition of templates through calcination. XRD analysis shows the crystallinity of the hierarchical ZSM-5 natural which indicates the synthesis was successful. SEM analysis shows the morphology of the material with the coffin like-shaped which is characteristic of the ZSM-5. The EDS analysis shows percent loading of Ni and Zn in ZSM-5 respectively is 6.38 % and 3.23 %. The ethyne carboxylation reaction with CO2 was carried out in a batch reactor with pressure variations of 1.5 bar, 2.5 bar, and 3.5 bar. The products formed were analyzed by HPLC. [ABSTRACT FROM AUTHOR]

Utilization of fossil fuel, charcoal, oil, and natural gases, which are carbon-rich materials, is widely used for human sustainability. However, utilization of such materials contributes to higher atmospheric CO2 concentration. The increase of CO2 emission leads to higher temperature and climate change due to ‘greenhouse effect’. Therefore, conversion of CO2 to value-added chemicals has drawn many attentions. In this research, carboxylation reaction of acetylene and CO2 has been carried out using mesoporous carbon modified by nickel and zinc metals as heterogeneous catalyst. Mesoporous carbon has been successfully synthesized using soft template method with pluronic F127 as template and phloroglucinol as carbon precursor. Mesoporous carbon was then modified with nickel and zinc (NiZn/MC) using homogeneous deposition precipitation method, followed by reduction for 90 min at 400 ºC under a flow of H2 (30 ml/min). XRD diffraction pattern showed peaks for 2θ around 31.79º, 34.54º, 36.31º, 44.04º, 51.51º, 56.51º, 62.22º and 75.68º which indicate the presence of NiZn and ZnO. EDX result revealed that mesoporous carbon material has been successfully modified by nickel and zinc metals, with 11.68 % and 8.69 % metal loadings for nickel and zinc, respectively. NiZn/MC catalyst was then used for carboxylation reaction of acetylene with CO2. The reactions were carried out in batch reactor with varied pressures, 1.5 bar, 2.5 bar and 3.5 bar. Acrylic acid, as the desired product, was not observed in analysis with HPLC. However, more polar species was noticed at retention time of 3.15 min, where the optimum pressure was found to be at 2.5 bar. [ABSTRACT FROM AUTHOR]

Synthesis of superabsorbent polymers based on chitosan modified by acrylic acid and acrylonitrile were conducted. The synthesis was done with a variety of modifiers including chitosan beads; acrylic acid modified chitosan (CTS-AA); acrylonitrile-modified chitosan (CTS-AN); and acrylic acid with acrylonitrile modified chitosan (CTS-AAAN). The products were characterized with FT-IR and DSC to determine the functional group and its stability to heat treatment and to investigate its swelling ability. FT-IR analysis indicates that in CTS-AA there are functional groups – COOH and –C=C, –C≡N group in CTS-AN, and –COOH, –C=C, –C≡N groups in CTS-AA-AN. DSC analysis shows that the superabsorbent polymers are more stable to heating treatment. The swelling test shows that CTS-AA has the highest swelling ability. The superabsorbent polymers are used to reduce the levels of Pb (II) metal ions in solution. This research study pH of the initial metal ion-solution, contact time, and the initial concentration of metal ions. The optimum conditions obtained are pH of chitosan bead 7.5 and pH 4 for CTS-AA, CTS-AN and CTS-AA-AN. The optimum contact time for all the superabsorbent polymers is 45 minutes. The optimum initial concentration for chitosan beads is 16.43 mg/L. While for CTS-AA is 56.75 mg/L, 44.50 mg/L for CTS-AN, and 18.52 mg/L for CTS-AA-AN. [ABSTRACT FROM AUTHOR]

A hydrogel is a hydrophilic polymer with a three-dimensional network that can retain a large amount of water and have swelling behaviour without dissolving in water. A hydrogel can be applied in various fields. Some are for Enhanced Oil Recovery (EOR), water harvesting, and diapers. Regarding its application, the hydrogel needs to have a high water absorption capacity. This research is aimed to prepare hydrogel that has a high absorption capacity by modifying the structure of the polymer, which was done by modifying the crosslinker. The hydrogel was prepared by grafting partially neutralised acrylic acid onto gelatinised starch in a reactor using potassium persulfate as an initiator with the temperature of 60 °C. Then, it was added by N,N’-methylene-bis-acrylamide (MBA) as a crosslinker to create three-dimensional networks. This hydrogel was characterised by Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and water absorbency. The result demonstrated that the highest absorption of water with variable concentration of crosslinker was 512.12 g/g. [ABSTRACT FROM AUTHOR]

In this research, acrylic acid based hydrogels were prepared and impregnated with magnetic nanoparticles to enhance the efficiency of the adsorption and desorption of heavy metals. Acrylic acid and itaconic acid both are short chain and possess -COOH group, therefore, they are easily copolymerized and hydrophilic in nature. The acrylic based hydrogel acts as a support to hold the magnetic nanoparticles. Hydrogels were synthesized by using acrylic acid and itaconic acid as monomers at different monomer ratios. The magnetic particles were incorporated through in situ precipitation method by immersing into 0.25 M Fe (II) and 0.5 M Fe (III) ion aqueous solutions in the molar ratio of 1:2 for metal ions loading. The swelling behaviour of the plain acylic acid hydrogel and plain acrylic acid-co-itaconic acid hydrogel that were soaked in two different water solutions such as sea water and distilled water were studied. Result shows that plain acrylic acid-coitaconic acid hydrogel has the tendency to swell more than plain acrylic acid hydrogel. The absorption and desorption capacity of the materials were tested in 0.1 M of cobalt and lead solutions. The materials show promising results and can be used to remove pollutants from industrial effluent. [ABSTRACT FROM AUTHOR]

In the present work phosphorous based acrylated epoxy resin was synthesized by reacting phosphorous based epoxy resin(DGEBHDPP) with acrylic acid . Different chemical methods such as hydroxyl value, epoxy equivalent weight, and the acid value were found out for characterization of the monomer and acrylated epoxy resin. Instrumental analysis such as FTIR and GPC were carried out. Styrene was used as a diluent in different proportions to prepare different types of styrenated resin systems. These systems were blended with conventional epoxy resin (DGEBA) in different ratios and blends were prepared. These blends were casted into the mould for the preparation of films and coated on mild steel panels. Flame-retardant and mechanical properties of films were found out. Different mechanical properties of coating such as pencil hardness, scratch hardness, adhesion, and flexibility were also found out. Chemical resistance properties were found out by dipping the coated panels into acidic, alkaline and sodium salt solutions. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to investigate the influence of bi-functional chain transfer agent, DMDO (1, 8-dimercapto-3, 6-dioxaoctane) at varying amounts on pressure-sensitive adhesive performance and determination of odor level according to VDA 270 test standard comparing to NDM species synthesized in the same manner. DMDO was incorporated at 0.15, 0.25 and 0.4% s/m ratio and NDM was incorporated at 0.25% s/m ratio into butyl acrylate and acrylic acid copolymer latexes via seeded semi-batch emulsion polymerization procedure. With the intended design, pressure-sensitive adhesive performance was investigated depending on the change in molecular weight. Since the increasing amount of DMDO obtained shorter polymer chains and consequently lower molecular weight, the peel adhesion and initial tack values were also increased enhancing better adhesive properties. NDM resulted in the highest initial tack value. However the peel adhesion value was between the peel adhesion values of DMDO-0.15% and DMDO-0.25%. According to the odor test results 0.15% and 0.25% DMDO content had an acceptable odor level whereas the one with 0.4% had very unpleasant and unacceptable odor like NDM at 0.25% for industrial scale uses. The present research is supported by Organik Kimya Research & Development Center, TURKEY. [ABSTRACT FROM AUTHOR]

Thin films of (PVA-PAA-Al2O3) nanocomposites composed of Poly (vinyl alcohol) (PVA), Poly (acrylic acid) (PAA) have been prepared with different concentrations of aluminum(III) oxide (Al2O3) nanoparticles and thicknesses by using the casting method. The main focus of the present work is to study the effects of ionizing radiation on the properties of the nanocomposites obtained. These films were irradiated with (50 kGy) of 60Co gamma rays. The optical properties of (PVA-PAA-Al2O3) nanocomposites have been measured in the range (300-800) nm of the wavelength. The transmittance, absorbance, coefficient of extinction (k), coefficient of absorption (α), the index of refraction (n) and the dielectric constants of real (ε_1) and imaginary (ε_2) components and are increasing by increasing the Al2O3 nanoparticles weight proportions. The polymers gap of energy (E_g) decreases by increasing of the Al2O3 nanoparticles concentrations. The results show that the effect of γ-irradiation leads to increase the absorbance, extinction coefficient of extinction (k), the index of refraction (n) and the dielectric constants (ε_1 and ε_2) of the real and imaginary while the energy gap (E_g) and the transmittance decreases. [ABSTRACT FROM AUTHOR]

The European Union “circular economy” aims to maintain the value of products, materials and resources for as long as possible, minimizing the generation of waste by recycling and reusing them [1]. The leather industry generates large amounts of waste, more than 55% of raw material (hides and skin), and over 99% are stored at the landfill [2, 3]. Part of these waste generated are untreated solid waste (hide and skin), meaning around 500-600 kg per ton of raw hides [4, 5]. A way to valorize the untreated hide and skin waste is production of three-dimensional molecular networks named, hydrogels, by cross-linking the proteins hydrolysated (obtained from skin and hide) with copolymers based on polyacrylamide, polyvinyl alcohol, oligo oxyethylene methacrylate, acrylic acid, maleic acid, cellulose, starch, gum. The hydrogels enriched in nutrients C, N, P, K encapsulated can be used as fertilizers in agriculture for degraded soils [6, 7]. In this work the releasing degree of organic compounds for three types of hydrogels designated as AMIGEL, POLYGEL and SMARTGEL obtained from pelt skin waste has been investigated. The releasing rate of organic compounds from composite fertilizers in water is essential for describing the carbon release in soil. It is demonstrated that collagen hydrogel functionalized with biopolymers, for instance starch, exhibits superior fertilization capacity as compared to synthetic polymers. [ABSTRACT FROM AUTHOR]

Starch is a natural biopolymer having many applications as industrial raw material. Nanoparticle technology can improve characteristic of starch, so its has lower suspension viscosity at high concentration with higher binding strength due to larger surface area. Starch nanoparticles obtained from the mangrove fruit has been dissolved in PEG / NaOH system and the polymerized in the presence of monomer acrylic acid and N,N’ Methylene Bisacrylamide crosslinker through radical polymerization. The semi – IPN hydrogel were characterized by using FTIR, XRD, DSC and SEM. The addition of mangrove fruit starch nanoparticles has a different impact on the water absorption ratio. [ABSTRACT FROM AUTHOR]

In this study, TiO2 doped acrylic acid-co-vinyl pyrrolidone (AA-co-VP) composite co-polymeric hydrogel was synthesized by free radical polymerization technique. Titanium dioxide (TiO2) were chosen because of its superior properties such as high activity, chemical stability, low cost, non-toxicity, and stability during irradiation. TiO2 doping were carried out by varying mass ratios as 0.05%, 0.5% and 1%. Conversion, cross-linking and swelling values of each hydrogel were calculated. According to swelling behavior, while TiO2 dope ratio increase, swelling value was also increased. Chemical, morphological and thermal properties of hydrogels were specified by using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy- Energy Dispersive X-Ray Spectroscopy (SEM-EDX), mapping and thermogravimetric analysis (TGA-DSC) techniques. TiO2 doping provides superior properties to co-polymeric hydrogel. Hydrogels have also characteristic properties of both acrylic acid and vinyl pyrrolidone. [ABSTRACT FROM AUTHOR]

Nanocomposite superabsorbent were prepared with nano sodium alginate used as the backbone, acrylic acid (AA) and acrylamide (Aam) as monomer, N, N- methylenebisacrylamide (MBA) as crosslinker, potassium persulfate (KPS) as initiator and montmorillonite as filler. The properties of superabsorbent nanocomposites were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Based on the FTIR spectra of the superabsorbent nanocomposite with in situ polymerization which have urea content, ammonium and potassium, can be seen from FTIR peaks to be compared with pure fertilizer. The highest swelling capacity obtained in urea nanocomposite SA 5 has a swelling capacity of 580 g/g, this is due to the presence of hydrophilic groups in the superabsorbent and urea, so it causes a high swelling capasity. Furthermore, ammonium nanocomposite has high enough swelling capacity of 465 g/g, while potassium nanocomposite is 420 g/g, respectively. The results of the study are good enough for the application of agricultural fertilizers. [ABSTRACT FROM AUTHOR]

Halogen free polymers for the core and cladding material are presented. A structured preform rod is made and accomplished as an optical fiber using a heat drawing process. The used material combination of poly(styrene-co-isobornyl methacrylate) (poly(ST-co-IBMA)) and poly(methyl methacrylate-co-isobornyl methacrylate) (poly(MMA-co-IBMA)) shows waveguide behavior with a refractive index difference of 0.038 and a numerical aperture of 0.35. Compared to poly(methyl methacrylate), temperature stability is improved due to an increased glass transition temperature of at least 135 °C for both materials. [ABSTRACT FROM AUTHOR]

This paper is about the investigation of the possibility of using polymeric and mineral hydrogels based on acrylic acid and liquid glass, modified by potassium titanate as thermoelectric elements, with the operation principle based on electrochemical processes at the solid electrolyte-electrode interface. Electrophysical characteristics of thermoelectrochemical cells were measured. The dependences of the open-circuit potential difference on the temperature gradient for cells based on zinc electrodes and various types of hydrogels are established. Hypothetical coefficient of Seebeck, calculated from the experimental data, was 1.5 mV/K for cells with electrolyte based on polyacrylic acid and 5.4 mV/K for cells with a mineral hydrogel. Thermogravimetric analysis of investigated electrolytes was shown that operation temperatures for polyacrylic electrolyte is lower of 80 °C, and for mineral hydrogel lower of 100 °C. [ABSTRACT FROM AUTHOR]

In the present work, polymer-silica hybrid latexes based on methyl methacrylate (MMA), butyl acrylate (BuA), 2-hydroxyethyl methacrylate (HEMA), and different inorganic precursors (tetraethoxysilane (TEOS), isobutyltriethoxysilane (IBTES), diethoxydimethylsilane (DEDMS), vinyltriethoxysilane (VTES)) were synthesized by emulsion polymerization and sol-gel process. The resulting latexes were characterized both as materials placed into plastic vials and as films deposited onto clean glass slides by various techniques including Fourier transform infrared (FT-IR), UV-vis spectrometry, thermal analysis (TGA) and water contact angles of film surfaces. The results showed that the surface wettability was changed from hydrophilic to hydrophobic by adding a precursor with vinyl organic group. For all hybrid latexes, the Si-O-Si groups give a strong absorption band in the spectral region between 1200-1000 cm-1 (asymmetric stretching vibration), which confirms the formation of a network structure inside the films. The antireflective films, due to diffuse reflection, have been given by the preparation from inorganic precursors. [ABSTRACT FROM AUTHOR]

The present work studies the dependence of mechanical properties of kenaf fibre (KF) reinforced acrylic based polyester composites on the processing parameters. Prior to moulding, non-woven kenaf fibre (NWKF) with areal density of 1200 g/m² was impregnated by acrylic based polyester resin using an impregnation line followed by a post-drying step. The flexural properties of the composites were investigated with respect to changes in impregnation and moulding conditions based on Design of Experiment (DOE) of Response Surface Methodology (RSM). RSM through Central Composite Design (CCD) was applied to develop a model of flexural properties with respect to the combination of processing variables. The mathematical regression models of the flexural properties were derived from the analysis of variance (ANOVA) to determine the model significance. All processing variables in linear terms exhibit significant effect on the flexural strength of the composites. Optimisation of the independent variables to maximise the flexural properties was estimated and verified. [ABSTRACT FROM AUTHOR]

This paper reports the preparation of novel polymer membranes by phase inversion at room temperature (25 °C), using acrylonitrile, acrylic acid, dimethyl sulfoxide and small amount of medicinal plant extract. We investigated the structure of the resulting membranes through Fourier Transform Infrared (FT-IR) spectroscopy and SEM microscopy. Also was determined the water content. FTIR-ATR spectra show that the peak at 1723 cm-1 shifted to lower wave number when medicinal plant extract (1715 cm-1) is added in the polymer matrix, indicated that the medicinal plant extract was successfully incorporated into the membrane matrix. SEM image reveal that the medicinal plant extract incorporated in membrane matrix reduced the amount of fissures and cracks and were distributed relatively uniform. Water content values of the prepared membranes are relatively high probably due to the immobilization of acrylonitrile and acrylic acid in polymer matrix. The small increase of water content can be due to the small amount of medicinal plant extract incorporated into the polymer membrane. [ABSTRACT FROM AUTHOR]

Polymeric nanoparticles have drawn tremendous attention to researchers and have utilized in diverse fields especially in biomedical applications. Nevertheless, question has raised about the safety and hydrophilicity of the nanoparticles to be utilized in medical and biological applications. One promising solution to this problem is to develop biodegradable polymeric nanoparticles with improve hydrophilicity. This study is focusing to develop safer and "greener" polymeric nanoparticles via inverse miniemulsion polymerization techniques, a robust and convenient method to produce water-soluble polymer nanoparticles. Acrylamide (Am), acrylic acid (AA) and methacrylic acid (MAA) monomers have chosen, as they are biocompatible, non-toxic and ecological. The effect of different volumes of cyclohexane towards the formation of polymer nanoparticles, particle size, particle size distribution and morphology of polymer nanoparticles are investigated. The formation and morphology of polymer nanoparticles are determined using FTIR and SEM respectively. The mean diameters of the polymer nanoparticles were in a range of 80-250 nm and with broad particle size distributions as determined by dynamic light scattering (DLS). Hydrophilic polyacrylamide (pAm), poly(acrylic acid) (pAA) and poly(methacrylic acid) (pMAA) nanoparticles were successfully achieved by inverse miniemulsion polymerization and have potentiality to be further utilized in the fabrication of hybrid polymer composite nanoparticles especially in biological and medical applications. [ABSTRACT FROM AUTHOR]

In this research, poly(styrene-co-acrylic acid-Cu) was prepared via emulsion polymerization.Cu contents were varied as 10%, 15% and 20% and mol ratio of styrene to acrylic acid as 1:1 and 2:1. Structure and surface of poly(styrene-co-acrylic acid-Cu) were characterized by FTIR (Fourier Transformed Infra Red), NMR (Nuclear Magnetic Resonance), and SEM/EDX (Scanning Electron Microcope/Energy Dispersive X-Ray) spectroscopy. The NMR spectra showed that the polymer was formed, however FTIR spectra showed that there were still unreacted monomers. SEM-EDX confirmed that copper (Cu) was dispersed uniformly on poly(styrene-co-acrylic acid-Cu) matrix. [ABSTRACT FROM AUTHOR]

This paper describes the use of artificial intelligence method in copolymer networks design. In the present study, we pursue a hybrid algorithm composed from two research themes in the genetic design framework: a Kohonen neural network (KNN), path (forward problem) combined with a genetic algorithm path (backward problem). The Tabu Search Method is used to improve the performance of the genetic algorithm path. [ABSTRACT FROM AUTHOR]

In this research work, biocomposites based on crosslinked particles of poly(acrylic acid), commonly used as superabsorbent polymer (SAP), and poly-L-lactic acid (PLLA) were developed to elucidate the role of the filler (i.e., polymeric crosslinked particles) on the overall physico-mechanical behavior and to obtain superabsorbent thermoplastic products. Samples prepared by melt-blending of components in different ratios showed a biphasic system with a regular distribution of particles, with diameter ranging from 5 to 10 μm, within the PLLA polymeric matrix. The polymeric biphasic system, coded PLASA i.e. superabsorbent poly(lactic acid), showed excellent swelling properties, demonstrating that cross-linked particles retain their superabsorbent ability, as in their free counterparts, even if distributed in a thermoplastic polymeric matrix. The thermal characteristics of the biocomposites evidence enhanced thermal stability in comparison with neat PLLA and also mechanical properties are markedly modified by addition of crosslinked particles which induce regular stiffening effect. Furthermore, in aqueous environments the particles swell and are leached from PLLA matrix generating very high porosity. These new open-pore PLLA foams, produced in absence of organic solvents and chemical foaming agents, with good physico-mechanical properties appear very promising for several applications, for instance in tissue engineering for scaffold production. [ABSTRACT FROM AUTHOR]

In order to investigate or study the structure of the subsurface using direct current it is better if the model validated using real small model using low current with low voltage, especially if the domain investigated doesn't have data to validate. With this real model it is easy to change the structure of the materials and acquire data, and also low cost. We design the box using acrylic because it is easy to build, lighter, and cheaper. The dimension of the box is 100 cm x 50 cm x 50 cm (x, y, z). Because this box is different from the real subsurface that doesn't have any bound so the simulation must be built to understand the properties of the box. In this paper we were modeling the subsurface homogenous and layered heterogeneous material. The simulation is accomplished by using finite different methods order one in two dimensions (2D) with boundary using acrylic resistivity. Firstly, the simulation is done using homogenous material and the result is agreed with analytical methods. After that we compute the two parallel layers with different materials. The result shows that the potential distribution between electrodes is distribute to all surface at top, bottom, left, and right. [ABSTRACT FROM AUTHOR]

This work focused on the synthesis of magnetite (Fe304)/poly(vinyl alcohol-co-acrylic acid) nanocomposite by in situ polymerization. The composite were characterized by FT-IR spectroscopy, XRD, SEM, TGA, AC and DC conductivity measurements. The spectroscopic studies revealed the molecular interaction between the polymer and nanocomposites. SEM, XRD indicated the uniform dispersion of nanoparticle inside the molecular chain of copolymer. TGA studies indicated the excellent thermal stability of copolymer nanocomposites. AC and DC conductivity of nanocomposites were higher than that of the copolymer and conductivity values were significantly increased with increase in concentration of metal oxide nanoparticles. These properties suggest that the polymer composite can be used as multifunctional material for nanoelectronics. [ABSTRACT FROM AUTHOR]

Biocompatible hydrogel based on acrylic acid (AA) and pectin was synthesized using gamma irradiation technique. AA was grafted onto pectin backbone that was extracted from dragon fruit under pH 3.5 and extracts and ethanol ratios (ER) 1:0.5. The optimum hydrogel system with high swelling capacity was obtained by varying the dose of radiation and ratio of pectin:AA. FTIR-ATR spectroscopy was used to verify the interaction while thermal properties were analyzed by TGA and DSC. Swelling studies was carried out in aqueous solutions with different pH values as to determine the pH sensitivity. The results show that the hydrogel with a ratio of 2:3 (pectin:AA) and 30 kGy radiation dose has the highest swelling properties at pH of 10. [ABSTRACT FROM AUTHOR]

The purpose of this study is to produce a novel pH and temperature sensitive hydrogel, composed of poly(acrylic acid) (PAA) and cellulose nanocrystal (CNC). CNC was extracted from kenaf fiber through a series of alkali and bleaching treatments followed by acid hydrolysis. The PAA was then subjected to chemical cross-linking using the cross-linking agent (N,N-methylenebisacrylamide) with CNC entrapped in PAA matrix. The mixture was casted onto petri dish to obtain disc shape hydrogel. The effects of reaction conditions such as the ratio of PAA and CNC on the swelling behavior of the hydrogel obtained towards pH and temperature were studied. The obtained hydrogel was further subjected to different tests such swelling test for swelling behaviour at different pH and temperature along with scanning electron microscopy (SEM) for morphology analysis. The hydrogel obtained showed excellent pH sensitivity and obtained maximum swelling at pH 7. Besides that, hydrogel obtained showed significant increase in swelling ratio when temperature of swelling medium was increased from 25°C to 37#176;C. SEM micrograph showed that the pore size of the hydrogel decreases with increase of CNC content proving that the hydrogel structure became more rigid with addition of CNC. The PAA/CNC hydrogel with such excellent sensitivity towards pH and temperature can be developed further as drug carrier. [ABSTRACT FROM AUTHOR]

The research investigated the effects of acrylic acid (monomer) and N, N,-methylenebisacrylamide, MBA (crosslinker) toward the percentage of gel content, swelling ratio and ionic strength of a starch-based hydrogel. Starch grafted on poly (sodium acrylate), St-g-PAANa hydrogel was prepared by incorporating starch extracted from Dioscorea hispida in NaOH/aqueous solution using different composition of acrylic acid (AA) and N, N-methylenebisacrylamide (MBA) in the presence of potassium persulfate (KPS) as chemical initiator. The highest gel content was observed at 1:30 ratio of starch to AA and 0.10 M of MBA. Results showed the highest swelling ratio was observed at 1:15 ratio of starch to acrylic acid and 0.02 M of MBA solution. The same results also gave the highest swelling ratio for the ionic strength study. The FTIR analysis was also conducted in order to confirm the grafting of AA onto starch backbone. [ABSTRACT FROM AUTHOR]