Dibutyl Maleate Research Articles

Applied and computational investigation of plasticizing effects of dibutyl maleate on polymethyl methacrylate acrylic resin material

In this study, the amount of change in the glass transition temperature (Tg) of PMMA was analyzed by DSC by adding different ratios of dibutyl maleate (DBM) plasticizer to polymethyl methacrylate (PMMA), which is used as the main ingredient of prosthetics in dentistry. For this, liquid DBM was added to powdered PMMA at a rate of 2, 5, 8 and 15 % by mass, and polymerization was carried out at 100 °C. Mechanical tests such as impact resistance, transverse resistance and maximum flexion tests were applied to these prepared mixtures. It was observed that there was a significant parallelism between the Tg values calculated from the DSC curves and the mechanical tests. The Tg value of PMMA was reduced by approximately half with the addition of DBM plasticizer. Additionally, the chemical interaction between PMMA and DBM was analyzed in the light of the Density Functional Theory (DFT) calculations. The binding energy for the mentioned interaction was determined as 1.591 eV. After both species interacted with each other, the glass transition temperature of the formed complex system was theoretically also predicted through the quantitative structure-property relationship (QSPR) model. For theoretical prediction of Tg, the molecular traceless quadrupole moment Θ and the molecular average hexadecapole moment Φ, are used. The change determined as experimental in glass transition temperature as a result of the interaction between PMMA and DBM was supported with theoretical calculations. Experimental and theoretical data are in good agreement.

Evaluation of dibutyl maleate/diesel blends on combustion, performance and emissions in a DI diesel engine

Ignition characteristics of diesel are weak due to higher viscosity and density especially at cold start conditions. So, it is seen that the usage of dibutyl maleate having high content of oxygen as an additive to improve the bad properties of pure diesel is essential and sensible. In this research, a single cylinder DI diesel engine was operated at four different engine loads including 4.12, 9.61, 15.10 and 20.60 Nm to observe and see the influences of dibutyl maleate on performance and combustion characteristics such as heat release rate, in-cylinder pressure, ignition delay etc. and thermal efficiency. It was found that in-cylinder pressure decreased with the addition of dibutyl maleate whereas remarkable increase was observed on pressure rise rate and ringing intensity with fuel blends. ID (Ignition delay) period increased with dibutyl maleate addition into diesel due to lower cetane number while combustion duration shortened with fuel blends compared to diesel. Besides, indicated thermal efficiency decreased about 20.18% and 24.25% with D90DBM10 and D90DBM20 respectively according to neat diesel at 15.10 Nm. Specific fuel consumption increased 5.08% and 8.13% with D90DBM10 and D90DBM20 respectively compared that neat diesel. It was also seen that cyclic variations increased in case of usage dibutyl maleate addition. Test results also demonstrated that HC (Hydrocarbon) and soot reduced while CO (carbon monoxide), CO2 (carbon dioxide) and NOx (nitrogen oxides) raised with the usage of dibutyl maleate compared to neat diesel.

Environmental and human health risks of plastic composites can be reduced by optimizing manufacturing conditions

New plastic composites are being manufactured outdoors, inside buried water and sewer pipes. This cured-in-place-pipe (CIPP) practice has been less expensive than other infrastructure repair options, but pollutants discharged during and after plastic manufacture pose environmental and human health problems. The study goal was to better understand how composite manufacturing conditions could be altered to reduce the amount of pollution released. Initiator loading, curing time, and curing pressure were modified for CIPP styrene and non-styrene ("HAP and VOC free") resin based composites. The styrene resin contained 39 wt% volatile organic compounds (VOC) whereas the non-styrene resin contained 4 wt% VOCs. Both resins contained hazardous air pollutants (HAP), endocrine disruptor, and carcinogenic compounds not listed on their safety data sheets. Vacuum pressure prompted greater VOC loss from the resins compared to ambient pressure manufacture. During both pressure manufacturing conditions, less than 1 wt% VOC was released from non-styrene composites into air compared to 8.8 to 26.4 wt% VOC released from styrene composites. VOCs including acetophenone, dibutyl maleate, p,α-dimethylstyrene, ethylbenzene, isopropylbenzene, methacrylic acid, 2-phenyl-2-propanol, styrene, toluene, and m-xylene were present in the non-styrene composite after manufacture. By doubling the styrene composite's initiator loading, styrene and styrene oxide residuals were reduced by 42 and 33 wt%, respectively. Manufacturer recommended conditions for the non-styrene composite resulted in <1 wt% initiator usage. The life cycle environmental impact assessment, which considered only composite VOC residual, predicted that styrene dominantly influenced ecotoxicity and human carcinogenic levels. Modifications to CIPP resin composition and the curing process can reduce environmental and human health impacts.

Microwave-assisted heterogeneous esterification of dibutyl maleate: Optimization using response surface methodology

Microwave-assisted synthesis of dibutyl maleate was carried out with heterogeneous catalyst, Amberlyst-15. Effect of process parameters such as mole ratio, reaction temperature, catalyst loading, and molecular sieves on the conversion was reported using Response Surface Methodology (RSM). Reaction conversion of 62.6% was achieved at optimum parameters of 1:3 acid to alcohol mole ratio, 5.5% (w/w) catalyst loading, 70°C temperature, and 6% (w/w) molecular sieves for reaction time of 60 min. The optimum parameters based on RSM were 1:3.14 acid to alcohol mole ratio, catalyst loading 5.35% (w/w), 77.19°C, and 64.77% predicted conversion. Pseudo- Homogeneous (PH), Eley Rideal (ER), and Langmuir Hinshelwood Hougen Watson (LHHW) models were used to fit experimental kinetic data. Studies revealed that the Eley-Rideal model suited the experimental data. The activation energy of the esterification reaction was calculated as 10.17 kJ/mol. Gibbs free activation energy (ΔG‡), enthalpy of activation (ΔH‡), and entropy of activation (ΔS‡) were evaluated.

Sooting tendency analysis of oxygenate-diesel blended fuels by the affecting indicators of carbon number, oxygen content and H/C ratio

This study experimentally assessed the sooting tendencies of the diesel fuel blended with typical oxygenated additives. Based on the known influential factors of oxygenated functional group, oxygen content, carbon number, and saturation degree, the functional numbers of carbon and oxygen atoms of the molecules were determined by considering the actual bonding ratio of carbon and oxygen producing CO and CO2 during the combustion of blends. The affecting indicators along with a calculation algorithm were proposed, taking into account the actual effect of each factor on sooting tendency. So-called indicators were termed the affecting oxygen content, carbon number and H/C ratio. Normalized Oxygen Extended Sooting Index (OESI) values incorporating the smoke point values were established to decrease with increasing blending percentage of the oxygenated additives in blends, following an exponential fitting relationship. The resulting exponents quantified the soot inhibition ability of the oxygenated additives, which decreased in the order: ethanol (EA) > n-butanol (NBA) > methyl tertiary-butyl ether (MTBE) > dimethoxy methane (DMM) > methyl decanoate (MD) > methyl butanoate (MB) > dibutyl maleate (DBM) > dimethyl carbonate (DMC). A combination of the absolute affecting indicator values generated by the suggested algorithm and their relative weights obtained by Relative Weight Analysis (RWA) could interpret the sooting tendency of most of the blended fuels very well. It was found that the sooting tendency was mainly determined by the absolute values of the affecting indicators, and the priority should follow the results by RWA, that decreased in the order of affecting carbon number > affecting oxygen content > affecting H/C ratio. This study could benefit the evaluation of the sooting tendency of the oxygenate-diesel blended fuels.

Mechanical and thermal properties of poly(lactic acid) plasticized with dibutyl maleate and fumarate isomers: Promising alternatives as biodegradable plasticizers

The use of plasticizers, polymer blends and composites have been reported as effective strategies to overcome the rigidity and brittleness of PLA, drawbacks that commonly limits its application. In this study poly(lactic acid) was plasticized with 7 and 12 wt% of dibutyl esters of maleic or fumaric acid. The choice of plasticizer was motivated by recent studies reporting the biodegradability of maleic and fumaric esters and their efficiency as green plasticizers. This current study evaluates how the chemical structure, specifically the cis–trans isomerism of the plasticizer, can affect the plasticizing properties on PLA. The thermal and mechanical properties of the plasticized specimens were evaluated by DSC, DMA, Stress-Strain and Relaxation tests. The results indicated that samples plasticized with dibutyl fumarate exhibited a lower glass transition temperature (Tg), lower Young’s modulus, and higher elongation at break than specimens plasticized with dibutyl maleate.

Investigation of performance and exhaust emissions of a chromium oxide coated diesel engine fueled with dibutyl maleate mixtures by experimental and ANN technique

Oxygenated fuel additives and thermal barrier coating (TBC) applications are noteworthy subjects that may reduce the exhaust emission levels and improve the performance of vehicles. In this study, the exhaust emission and performance characteristics of chromium oxide (Cr2O3) coated single cylinder diesel engine fueled with dibutyl maleate (DBM) blends were investigated. In addition, an artificial neural network (ANN) which had the ability to reduce experimental repeats, cost and time loss was designed and its performance was examined. Piston crown and valves of diesel engine were treated with chromium oxide. Experiments were carried out with DBM3, DBM6, DBM9 blends that contain 3%, 6%, 9% by volume of DBM, respectively. The results indicated that carbon monoxide (CO), hydrocarbon (HC), smoke density, brake specific fuel consumption (BSFC) values reduced in the isolated engine (IE) whereas nitrogen oxide (NOX), exhaust gas temperature (EGT) and engine vibration (EV) values increased compared to standard engine (SE). The addition of DBM reduced CO, HC, smoke density, EGT, and engine vibration whereas NOX and BSFC values increased in both IE and SE. Consequences of ANN revealed that exhaust emission and performance attributes of an engine can be estimated with high accuracy.

Simultaneous enhancement of CO2 permeability and CO2/CH4 and CO2/N2 selectivity via incorporating dense, rubbery and CO2-philic vinyl acetate- based copolymers into poly(ethylene oxide-b-amide 6) membranes

In this work, blend membranes based on poly(ethylene oxide-b-amide 6), i.e. Pebax 1657, and 30 wt% of dense, rubbery and CO2-philic vinyl acetate/ dibutyl maleate (VAc/DBM) copolymers with different chemical compositions were prepared. Depending on the copolymer composition, glass transition temperature (Tg) of copolymers were measured to be in the range of 7–23 °C. Copolymer composition dependency of the copolymers' density was also evaluated. Interaction of the various components present in as well as morphology of the blend membranes were investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and field emission scanning electron microscopy (FE-SEM) analyses. The permeability of CO2, CH4 and N2 gases was determined at a pressure of 3–9 bar and a temperature higher than Tg of CO2-philic VAc/DBM copolymers, i.e. 30 °C. Although copolymers had densities higher than that of pristine Pebax 1657; however, CO2 diffusion increased by adding these copolymers. It can be attributed to the increased volume fraction of amorphous portion in the blend membranes, which is responsible for gas transport, as well as to enhanced mobility of polymer chains. CO2 permeability and CO2/CH4 and CO2/N2 selectivities were found to increase simultaneously in all of the blend membranes in comparison with the pristine Pebax 1657. It may be attributed to enhanced CO2-philicity of the blend membranes, resulting in the enhanced CO2/CH4 (or N2) solubility selectivity, as well as to the enhanced fractional free volume in the blend membranes with free volume sizes suitable for transport of smaller molecules of CO2, resulting in the enhanced CO2/CH4 (or N2) diffusivity selectivity. The best results were found for a blend membrane containing 30 wt% VAc/DBM copolymer with 72 mol% VAc in the chains, where CO2 permeability and CO2/CH4 and CO2/N2 selectivities increased about 198%, 157% and 156%, respectively, compared to the pristine Pebax. Both CO2 permeability and selectivity increased by increasing pressure in the range of 3–9 bar, while plasticization phenomenon was not observed, indicating that the blend membranes prepared in the present work can practically be used for efficient separation of CO2 from the mixed gases.

Preparation and characterization of novel VAc/VeoVa10/DBM/VTES quadripolymer latex emulsified with green surfactants

The novel vinyl acetate (VAc)/vinyl neo-decanoate (VeoVa10)/dibutyl maleate/triethoxy vinyl silane quadripolymer latex was prepared via the semi-continuous seeded emulsion polymerization emulsified with disodium laureth sulfosuccinate (AEMES) as anionic surfactant and beta-cyclodextrin (β-CD) mixture as emulsifier and initiated with potassium persulfate (KPS), respectively. The chemical compositions of copolymer was determined by Fourier transform infrared spectromer (FTIR). The glass transition temperature ( Tg) of the copolymer was measured by differential scanning calorimetry. The water resistance of the film was assessed by the water contact angle measurement. The conditions of preparing the novel latex were optimized and obtained as follows. The amount of AEMES and β-CD mixtures were 6 wt% and the mass ratio of AEMES to β-CD were 1:1. The dosage of KPS was 0.6 wt% and the mass ratio of VAc to VeoVa10 was 3:1. The amount of dibutyl maleate and triethoxy vinyl silane was 4% and 3%, respectively. In this case, the conversion percentage of the mixed monomers was 99.0% and the polymerization stability was good.

Facile synthesis of chiral (right-handed) calcium carbonate with exceptional enantioseparation performance of dibenzoyltartaric acid

The chiral morphology of calcium carbonate (mainly vaterite) was successfully synthesized by using CaCl2 under l-aspartic acid guiding by diffusion of in-site generation of CO2 and NH3 from (NH4)2CO3 and NH3·H2O. Its structure was characterized by XRD, SEM/TEM and FT-IR, it indicated that the helical-shaped chiral calcium carbonate was uniform in a diameter of 10–20 μm and height of 1 μm, and tortuous nanosheets with a thickness of 50 nm were evolved more abundant from center to edge in counterclockwise. The enantioseparation performance for racemic dibenzoyltartaric acid was evaluated, the chiral calcium carbonate showed certain recognition ability for l-dibenzoyltartaric acid due to its better matching with l-dibenzoyltartaric acid molecules in stereochemical structure. Chiral separation ability for dibenzoyltartaric acid could be significantly improved by dibutyl maleate modification of chiral calcium carbonate; the maximal ee values for dibenzoyltartaric acid increased from 20.62% to 62.15%. The synergism of chiral helical-shaped suprastructure, large proportion of vaterite and modification of surface by functional group resulted in the excellent enantiomer separation.

Esterification of maleic acid and butanol using cationic exchange resin as catalyst

Dibutyl maleate is a perfumery ester used as an intermediate in the production of paints, adhesives, and copolymers. Esterification of maleic acid and butanol was studied in presence of acidic cation exchange resin as a catalyst. The objective of this work was to test the suitability and efficacy of heterogeneous catalysts such as Indion 225H and Amberlyst-15 in the synthesis of dibutyl maleate. Various parameters deciding the conversion of reaction such as mole ratio, catalyst loading, molecular sieves, speed of agitation and effect of temperature were optimized for the maximum rate and conversion. The activation energy was calculated as 71.5 kcal/mol. Diffusivity value $$\hbox {D}_{\mathrm{AB}}$$ (maleic acid in n-butanol) at $$80\,^{\circ }\hbox {C}$$ was calculated as $$5.08\times 10^{-10}~\hbox {m}^{2}/\hbox {s}$$ and effective diffusivity ( $$\hbox {D}_{{\text {e-A}}})$$ was calculated as $$5.08\times 10^{-11}\,\hbox {m}^{2}/\hbox {s}$$ . Solid–liquid mass transfer coefficient ( $$\hbox {k}_{{\text {sl-A}}}$$ ) was calculated as $$6.77\times 10^{-6}\,\hbox {m/s}$$ for the particle size of Amberlyst-15 as 0.5 mm. Synopsis. Synthesis of dibutyl maleate was carried out using ion exchange resin as a catalyst. Effect of various parameters on the conversion of reaction like mole ratio, catalyst loading, molecular sieves, the speed of agitation and effect of temperature was studied.

Synthesis and characterization of cassava starch with maleic acid derivatives by etherification reaction

Cassava starch was grafted with three different esters by the etherification reaction and its modification was characterized by 1H NMR, FTIR, DSC, SEM, XDR, contact angle and SLS. The samples grafted with diethyl maleate, dipropyl maleate, and dibutyl maleate showed DS values of 2.3, 1.0 and 2.0, respectively, determined from 1H NMR analysis and confirmed by FTIR analysis, with the appearance of bands at 1721, 1550 and 1126cm−1. The FTIR, XRD, SEM and DSC results indicated a change in the intra and intermolecular hydrogen interactions in the grafted starch when compared to native starch. Based on the contact angles, it was observed that the macromolecular starch chain acquired hydrophobic characteristics through the substitution of the hydrogens with di maleate esters. The characteristics acquired by grafted starch allow it to be used for the encapsulation of bioactive molecules for the production of bioactive packages and the production of biodegradable packages.

Production of Dibutyl Maleate with SO42-/Fe2O3 Solid Acid Catalyst

This paper explores the impact of catalyst dosage, molar ratio of normal butanol to maleic anhydride, reaction temperature and reaction time, etc. on esterification rate in combination with the synthesis of dibutyl maleate with SO42-/Fe2O3 solid super acid catalyst prepared with ferrous sulfate, a by-product to produce titanium dioxide. It turned out that the preferable conditions for the synthesis of dibutyl maleate with SO42-/Fe2O3 solid super acid catalyst are as follows: catalyst dosage accounting for 2.0% of the amount of reactive material, molar ratio of alcohol to acid of 3.5:1, reaction temperature of 120°C and reaction time of 3h. Under the preferable conditions, the esterification rate of normal butanol to maleic anhydride can reach 90% in esterification reaction. The infrared spectroscopy shows that the synthetic dibutyl maleate conforms to the standard diagram.

Correlation of Experimental Liquid–Liquid Equilibrium Data for Ternary Systems Using NRTL and GMDH-Type Neural Network

In this work, liquid–liquid equilibrium (LLE) data for the ternary systems (water + propionic acid + solvent) were experimentally obtained at atmospheric pressure and 298.2 K. The ternary systems show type-1 behavior of LLE. Cyclopentane, cyclopentanol, 2-octanone, and dibutyl maleate were chosen as solvent and it has been noted that there are no data in the literature on these ternary systems. The consistency of the experimental tie-line data was checked using the Hand and Othmer-Tobias correlation equations. A comparison of the extracting capabilities of the solvent was made with respect to the distribution coefficients and separation factors. The correlation of the experimental tie-line data was confirmed by the NRTL thermodynamic model. A Group Method of Data Handling (GMDH)-type neural network (NN) was also used to correlate the experimental tie-lines. It is shown that the results of the both models cohere with the experimental values.

Enhancement of the CO2-philicity of poly(vinyl ester)s by end-group modification with branched chains

Four copolymers of vinyl acetate (VAc) and comonomers with different branched chains—dipropyl maleate (DPM), dibutyl maleate (DBM), diisobutyl fumarate (DiBF) and dineopentyl maleate (DNM)—were synthesised, and their CO2-philicity was evaluated by cloud point measurements. It was shown that poly(VAc-alt-DNM), containing the highest branched structure degree, had a 10% lower cloud point pressure at 40°C than poly(VAc-alt-DBM)’s, the best CO2-philic hydrocarbon polymer available. Both ab initio calculations and molecular dynamics (MD) simulations showed that the highly branched structure weakened polymer–CO2 interactions. However, the MD results for the cohesive energy density, solubility parameter, free volume fraction and radial distribution functions indicated that the more highly branched end groups contributed to an increase in the free volume fraction of the polymer, leading to low polymer–polymer interactions. Thus, the introduction of highly branched end groups into the polymer backbone was an efficient way to enhance the CO2-philicity of hydrocarbon polymers.

Post-polymerization modification of unsaturated polyesters by Michael addition of N-heterocyclic carbenes

The post-polymerization modification of unsaturated polyesters, three polymaleates and a polyfumarate, was performed by the Michael addition of N-heterocyclic carbenes (NHCs) to produce thermally stable unsaturated polyesters. The model reactions of NHCs, 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene (TPT), and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IDipp), with dibutyl fumarate and dibutyl maleate selectively proceeded to give the corresponding Michael adducts, whereas 1,3-di-tert-butylimidazol-2-ylidene (ItBu) exclusively catalyzed the isomerization of dibutyl maleate. Based on these results, reactions of the unsaturated polyesters with TPT and IDipp were investigated. The polyesters bearing NHCs as side chains were obtained in good-to-high yields. The number of NHC-incorporated units can be controlled by the amount of added NHCs, and the obtained polyesters showed better solubility in common organic solvents. It is noteworthy that the glass transition temperatures (Tgs) were widely tunable and increased linearly with increasing NHC content because of the stiff and bulky structure. In addition, reactions of the unsaturated polyesters with TPT in the presence of water allowed Michael addition and transfer hydrogenation to occur simultaneously. Radical cross-linking of the NHC-incorporated unsaturated polyesters with styrene produced thermally stable and fully miscible polyester resins. The Michael addition of N-heterocyclic carbenes (NHCs) to the unsaturated polyesters, polymaleates and a polyfumarate, produced the polymers bearing the NHCs as side chains in good-to-high yields. The glass transition temperatures of the obtained polymers were widely tunable and increased linearly with the increasing NHC content. The stiff and bulky structures of the NHCs can reduce the mobility of the polymer main chain. The simultaneous Michael addition and transfer hydrogenation of the unsaturated polyesters have also been performed by the reaction with an NHC in the presence of water.

Novel ceramic processing method for substitution of toxic plasticizers

A systematic screening of plasticisers for a polyvinyl butyral based binder system revealed that dibutyl maleate, dibutyl adipate and Pycal 94 are promising and less toxic alternatives to the very harmful but frequently used dibutyl phthalate. Pycal 94 seems especially promising as it unlike the two other candidates did not require a co-plasticiser, such as a polyethylene glycol, thus simplifying the system and reducing the risk of unwanted cross-interactions.An effective and systematic procedure for substitution of the plasticiser, while maintaining chemical compatibility and mechanical properties, was also demonstrated. Incompatible systems were discarded in an initial broad screening while primary systems were further evaluated based on debinding properties, mechanical properties, flow behavior as well as sintering properties of ceramic tapes. The thermomechanical characterization performed on dried drops of binder and their corresponding tapes show strong similarities in the strain/stress profiles, validating the qualitative method used.

ω-Iodinated poly(dimethylsiloxane) as a chain transfer agent in iodine transfer radical polymerization of vinyl acetate and dibutyl maleate: synthesis and structural characterization

Iodine transfer radical homo- (ITP) and copolymerization (ITCP) of vinyl acetate (VAc) with dibutyl maleate (DBM) initiated by 2,2׳-azobis(isobutyronitrile) (AIBN) were performed in bulk at 80 °C in the presence of ω-iodo- terminated poly(dimethylsiloxane) (PDMS-I) as a macro-chain transfer agent (macro-CTA). 1H-NMR and gel permeation chromatography (GPC) results confirmed formation of the PDMS-b-PVAc diblock copolymer. Moreover, the results of 1H-NMR showed that the iodo-terminated chain ends are unstable and decompose to the aldehyde moieties. On the other hand, different behaviour was observed in the ITCP of the VAc and DBM. 1H-NMR and GPC results showed that presence of DBM in the reaction medium leads to degradation of the C-I bond of the PDMS-I, resulting in the generation of HI. In fact, PDMS-I acts as in situ generator of the CTA in the presence of DBM via reaction between the generated HI and VAc. In other words, it was found that P(VAc-co-DBM) copolymer chains are synthesised by ITP mechanism in the presence of in situ generated 1-iodoethyl acetate as a CTA. Therefore, a mixture of PDMS and P(VAc-co-DBM) chains was obtained.

Experimental measurements and thermodynamic modeling of the cloud point pressure for solubility of copolymers of vinyl acetate and dibutyl maleate in supercritical CO2

In this study the cloud point pressure for the solubility of copolymers of vinyl acetate and dibutyl maleate in supercritical carbon dioxide were measured and modeled. The copolymers investigated have different molecular weights, with varying structures. The cloud point pressure data were modeled using the Perturbed Chain Polar Statistical Associating Fluid Theory (PCP-SAFT) equation of state (EoS) that was developed for the prediction of the phase behavior of polar polymers which are soluble in supercritical carbon dioxide (J. of Supercritical Fluids 97 (2015) 45–50). Using this model, the cloud point pressure of the polymer-supercritical CO2 systems were correlated by taking into account quadrupole-quadrupole interactions between carbon dioxide and the polymer segments through the PCP-SAFT EoS. Thus, the new parameters were determined for the copolymers studied in this work. Moreover, we applied PC-SAFT EoS for the same systems. It is shown that the results are obtained using the PCP-SAFT EoS is superior respect to PC-SAFT so that the present EoS can be applied to calculate the cloud point pressure of the copolymer-CO2 systems and the deviation of the calculated values from experiment values are low.

Effect of cenosphere surface treatment and blending method on the tensile properties of thermoplastic matrix syntactic foams

ABSTRACTThe influence of cenosphere surface treatment and blending method on the properties of injection molded high‐density polyethylene (HDPE) matrix syntactic foams is investigated. Cenospheres are treated with silane and HDPE is functionalized with dibutyl maleate. Tensile test specimens are cast with 20, 40, and 60 wt % of cenospheres using injection molding. Modulus and strength are found to increase with increasing cenosphere content for composites with treated constituents. Highest modulus and strength were observed for 40 and 60 wt % untreated mechanically mixed and treated brabender mixed cenospheres/HDPE blends, respectively. These values are 37 and 17% higher than those for virgin and functionalized HDPE. Theoretical models are used to assess the effect of particle properties and interfacial bonding on modulus and strength of syntactic foams. Brabender mixing method provided highest ultimate tensile and fracture strengths, which is attributed to the effectiveness of Brabender in breaking particle clusters and generating the higher particle–matrix surface area compared to that by mechanical mixing method. Theoretical trends show clear benefits of improved particle–matrix interfacial bonding in the strength results. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43881.