Molar Ratio Of Maleic Anhydride Research Articles

Preparation of Polycarboxylate Terpolymer High Performance Water Reducer of MA-AA-F108

In aqueous solution, the modified polyether (F108), maleic anhydride (MA), acrylic acid (AA) as raw materials, a novel polycarboxylate high performance water reducer of MA-AA-F108 was synthesised from free radical copolymerized through oxidation-reduction initiator system. Additionally, the polymerization conditions were optimized. The results indicate that the copolymer can be prepared under such optimum conditions, i.e., 3:3:2 molar ratio of MA, AA and F108, 0.5% of the mass fraction of oxidation initiator, 0.6% of the mass fraction of reduced initiator and 0.3% of the mass fraction of regulator, the results showed that the polyether-type polycarboxylic water reducer has excellent dispersing ability.

Synthesis and Properties of an New Amphoteric Retaning Agent

The mono polyethylene glycol maleate (MPEGM) was prepared by direct esterification of maleic anhydride (MAH) and polyethylene glycol (PEG). The yields of monoester (YM) could reached to 96% when the molar ratio of MAH and PEG was 1.2 using 2 wt% p-toluene sulphonic acid (PTSA) as catalyst at 95°C for 3 h. The amphoteric retaning agent (ARA) with excellent retanning properties was synthesized by copolymerization when the molar ratio of methacrylic acid (MA), MPEGM and dimethyl diallyl ammonium chloride (DMDAAC) was 3 : 1 : 0.2 using 3 wt% ammonium persulfate (APS) as initiator at 90°C for 4 h. The applied results showed that retanned leather by ARA had excellent selective filling and can improve remarkable the flexiblity and elasticity. The chemical structure of the ARA was characterized by FTIR.

Preparation and Properties of Polycarboxylate Superplasticizer with Hydroxy Terminated Side Chains

Maleic anhydride modified polycarboxylates superplasticizes (MPC) was synthesized from allylic poly (ethylene oxide ether) (APEG), maleic anhydride (MAH), sodium methylallyl sulfonate (SMAS) using ammonium persulfate (APS) as initiator. The optimal MPC with best fluidity was got at 90 °C when molar ratio of MAH, APEG, SAMA was 2.75∶1∶0.4 in the present of 4.5 mol% APS of all the monomer molars. MPC which possessed hydroxyl terminated side chains shows some difference in fluidity retarding related to the conventional superplasticizers possessed methoxy terminated side chains.

Synthesis and Characterization of Alkyd Resin Based on Soybean Oil Polyols

Soybean oil-based alkyd resin was prepared using soy-based polyol, maleic anhydride and phthalic anhydride. The soy-based polyol was obtained through the epoxidization of soybean oil, followed by ring-opening with methanol and, the hydroxyl values of soybean oil-based polyols used in this reaction is 169.93 mgKOH/g. In the reactions of soy-based polyol, maleic anhydride and phthalic anhydride, the molar ratio of hydroxyl value is equal to carboxyl value and the molar ratio of maleic anhydride to phthalic anhydride is 2:1, 1:1 and 1:2, respectively. 1% hydroquinone based on total reactants was used as inhibitor of polymerization, 1% dibutyltin oxide was used as catalyst.

STYRENE ASSISTED MELT FREE RADICAL GRAFTING OF MALEIC ANHYDRIDE ONTO HIGH DENSITY POLYETHYLENE AND PROPERTIES OF THE GRAFT COPOLYMER

Free radical melt-grafting of the multi-monomer system of maleic anhydride(MAH) /styrene(St) onto high density polyethylene(HDPE) prepared by a single-screw extruder was studied.It was found that the addition of St monomer could significantly improve the MAH grafting level of the grafted HDPE.With increasing the St concentration,the graft degree of MAH first increased and then decreased a little.The maximum MAH grafting degree and the minimum melt flow rate were obtained when the molar ratio of MAH to St was approximately 1∶ 1.The higher the graft degreet,he smaller MFR value was,suggesting that the grafted PE chains induced intermolecular entanglements.The mechanical properties of the grafted polymer with the addition of small portions of St monomer were better than those of the neat HDPE in this case.The mechanism of the multi-monomer melt grafting HDPE system was also discussed.It was proposed that MAH and St interacted and copolymerized with each other in the melt grafting system.The grafting of St-MAH copolymer(SMA) onto HDPE greatly increased the grafting degree of the grafted HDPE.When the amount of St is larger than MAH,St would be first grafted onto the PE backbonei,nhibiting the grafting of SMA.Besidest,he cross-linking of PE was well depressed due to the increase of graft degree in the multi-monomer melt grafting systems.And no obvious gel was obseved in the reflux process.

Homogeneous Esterification of Xylan-Rich Hemicelluloses with Maleic Anhydride in Ionic Liquid

Generation of bioenergy, new functional polymers, or chemicals and biomaterials from hemicelluloses are important uses for biomass. In this paper, a novel functional biopolymer with carbon-carbon double bond and carboxyl groups was prepared by a homogeneous esterification of xylan-rich hemicelluloses (XH) with maleic anhydride in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid using LiOH as catalyst. The biopolymers with degrees of substitution (DS) between 0.095 and 0.75 were accessible in a completely homogeneous system by changing reaction temperature, reaction time, the dosage of catalyst, and the molar ratio of maleic anhydride to anhydroxylose unit in XH. Results obtained from FT-IR and (13)C NMR spectroscopies confirmed the structure of hemicellulosic derivatives with carbon-carbon double bond and carboxyl groups, implying an efficient method to prepare a novel and important functional biopolymer for biomaterials.

Microwave‐assisted synthesis of polyaspartic acid and its effect on calcium carbonate precipitate

AbstractWithout organic solvent or catalyst, polyaspartic acid (PASP) was synthesized from maleic anhydride (MA) and ammonia (AN) under microwave irradiation. The influences of the molar ratio of maleic anhydride to ammonia and the microwave output power and irradiation time on product yield were investigated. Also, the function of microwave in the process was simply addressed. The results showed that when the molar ratio of MA/AN was 1.2, the output power was 900 W, the irradiation time was 3.5 min, and the product yield was highest and its inhibition performance on calcium carbonate was as good as the polymer synthesized by conventional pyrocondensation polymerization. The main function of microwave was its heat effect. Characterization of the product was carried out by IR, 1HNMR, and 13CNMR spectra and the results showed that the product was PASP. The microwave‐assisted synthesis process of PASP has many advantages, including quicker reaction rate, high purity, lower cost, and little pollution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:358–364, 2007

Styrene‐assisted free‐radical graft copolymerization of maleic anhydride onto polypropylene in supercritical carbon dioxide

AbstractThe free‐radical graft copolymerization of maleic anhydride (MAH) onto polypropylene (PP) with the assistance of styrene (St) in supercritical carbon dioxide (CO2) was studied. The effects of the St concentration and initiator concentration on the functionality degree of the grafted PP in supercritical CO2 were investigated. The addition of St drastically increased the MAH functionality degree, which reached a maximum when the molar ratio of MAH and St was 1:1. St, an electron‐donating monomer, could interact with MAH through charge‐transfer complexes to form the St–MAH copolymer (SMA), which could then react with PP macroradicals to produce branches by termination between radicals. There was SMA in the grafting reaction system characterized by Fourier transform infrared and differential scanning calorimetry. Furthermore, the highest MAH functionality degree was obtained when the concentration of 2,2′‐azobisisobutyronitrile (AIBN) was 0.6 wt % based on PP. The effects of the temperature and pressure of supercritical CO2 on the functionality degree of the grafted PP were analyzed. An increase in the temperature accelerated the decomposition rate constant of AIBN, thereby promoting the grafting reaction. In addition, an increase in the temperature increased the diffusion of monomers and radicals in the disperse reaction system of supercritical CO2. The highest degree of functionality was found at 80°C. Also, the functionality degree of grafted PP decreased with an increase in the pressure of supercritical CO2 within the experimental range. The morphologies of pure PP and grafted PP were significantly different under polarizing optical microscopy. The PP spherulites were about 38 μm in size, and the grafted PP spherulites were significantly reduced because of heterogeneous nucleation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 853–860, 2003

Involvement of lysine residues of goat serum albumin in high-affinity binding of bilirubin

Four maleylated derivatives of goat serum albumin having percent modification as 40%, 46%, 84% and 98% were prepared using varying molar ratio of maleic anhydride over protein. These preparations were found to be pure, both with respect to size and charge as judged by gel filtration and polyacrylamide gel electrophoresis. Maleylation caused significant change in protein conformation as revealed by the change in Stokes radius and frictional ratio of serum albumin, from 3.46 nm and 1.28 to 4.96 nm and 1.79, respectively, upon 98% modification. Immunodiffusion results of native and modified albumins with anti-goat serum albumin antiserum also suggested significant conformational changes in serum albumin upon maleylation. About 88% reduction in bilirubin binding was observed after modification of 98% amino groups of serum albumin as studied by visible difference spectroscopy at pH 8.0, and at 0.15 ionic strength. Increase in ionic strength to 1.0 did not lead to any significant reversal in bilirubin binding. These results prove the involvement of lysine residues in bilirubin-albumin interaction.

Synthesis and characterization of cyclomaltoheptaose ( Z)-2-butenedioic monoesters

The reactions of cyclomaltoheptaose (β-cyclodextrin) and maleic anhydride were investigated, and the resulting products characterized by i.r., proton, and carbon-13 n.m.r. spectroscopy. The 13C-n.m.r. spectra show preferential esterification at HO-6 under various conditions of temperature and concentration of reactants and of catalyst. An increase of temperature, catalyst concentration, or initial molar ratio of maleic anhydride to cyclodextrin increases the rate of esterification.

Photo‐copolymerization of methacryloyl‐L‐valine methyl ester, methacryloyl‐D‐valine methyl ester, and maleic anhydride

AbstractPhotocopolymerization of methacryloyl‐L‐valine methyl ester (L‐MAVM), methacryloyl‐D‐valine methyl ester (D‐MAVM) and maleic anhydride (MAn) was carried out in dioxane at 25°C without initiator at an initial total concentration of the three monomers of 1 mole/1.; the molar ratio of MAn in the feed to the sum of L‐ and D‐MAVM was 1 : 1 in all cases. The copolymer with a 1 : 1 molar ratio of MAVM and MAn was always obtained regardless of the feed molar ratio of L‐ and D‐MAVM. The circular dichroism (CD) spectra of the copolymer before and after hydrolysis showed a linear relationship between the monomer unit ellipticity at 222 nm and the molar feed ratio of L‐ and D‐MAVM and suggested the induction of an asymmetric center into the polymer main chain. The results also indicated that the configuration of the induced asymmetric carbon atoms would be arranged according to that of fed MAVM monomer.