Presence Of N-butanol Research Articles

Critical role of support crystal structures on highly selective hydrodeoxygenation of lignin-derived vanillin over Pd/ZrO2 catalysts

Hydrodeoxygenation (HDO) of bio-oils obtained by rapid pyrolysis of biomass into high value-added chemicals generally required harsh conditions. Herein, three kinds of mixed-phase ZrO2 supports (denoted as ZSX, X = 2–4) with different crystal structure proportions were prepared by one-pot hydrothermal synthesis method, and their performance on the properties of Pd/ZrO2 catalysts were investigated for vanillin HDO. Pd/ZS3 exhibited excellent efficiency in HDO of vanillin, a typical model compound of lignin, achieving approximately 100% yield of 2-methoxy-4-methylphenol (MMP) in presence of n-butanol as solvent and polymethyl hydrogen siloxane (PMHS) as hydrogen donor under mild conditions (35 °C, 1 h). It was due to catalytic synergy of exposed metal active sites, oxygen vacancies (Ov) and acid sites to occur electron transfer and enhance interaction between Pd and ZrO2. By tuning the crystal structure of ZrO2 support, the influence of Ov and acid sites of Pd/ZrO2 over vanillin HDO performance was investigated, Pd/ZS2 with abundant Ov and Pd/ZS4 with substantial acid sites promoted hydrogenation and hydrogenolysis, respectively, Pd/ZS3 possessed preferable conversion and selectivity as having the properties of both at once. Additionally, reaction pathway was also proposed in which vanillin was converted to MMP by combining intermediate of 4-hydroxy-methyl-2-methoxyphenol (HMP) with active hydrogen species while removing water. This developed catalysts with different crystalline highlighted an enormous promise for HDO of bio-oils into green fuel under mild conditions.

Study on characteristics of marine heavy fuel oil and low carbon alcohol blended fuels at different temperatures

The current study proposes heavy fuel oil (HFO)-methanol/ethanol blends as sustainable way shipowners can limit their emissions to acceptable levels. However, the blends of HFO- methanol/ethanol present miscibility problems, and little has been reported about the improvement of this situation within the existing literature. Hence, the primary aim of the current study is to prepare a blend of HFO- methanol/ethanol in the presence of n-butanol, tetrahydrofuran (THF), and polyoxymethylene dimethyl ethers (PODE), that can be kinetically stable for at least 48 h. Also, the ternary systems’ viscosity, corrosivity, and sulfur content relative to that of neat HFO were ascertained. Finally, an economic feasibility of using the proposed ternary systems in comparison to an HFO + scrubber system, as two different pathways of meeting SOx emission standards is conducted. The ternary blends were undisturbed at an experimental temperature (20 °C, 40 °C, and 50 °C) for at least 48 h to observe their mutual solubility. After maintaining a 2-day single-phase solution, the best co-solvent for methanol-containing blends was PODE, and that of ethanol was THF. The oxygenated fuels decreased the kinematic viscosity well below that of a preheated/unheated HFO; reducing preheating cost and energy. The corrosivity of the ternary systems were extremely low and negligible. The HFO blend at 1:1 ratio showed a significant decrease in sulfur content of neat HFO. The study promotes the wide use of oxygenated fuels in the shipping industry; a positive step towards decarbonizing this transportation sector.

Efficient biomass saccharification using a novel cellobiohydrolase from Clostridium clariflavum for utilization in biofuel industry.

The present study describes the cloning of the cellobiohydrolase gene from a thermophilic bacterium Clostridium clariflavum and its expression in Escherichia coli BL21(DE3) utilizing the expression vector pET-21a(+). The optimization of various parameters (pH, temperature, isopropyl β-d-1-thiogalactopyranoside (IPTG) concentration, time of induction) was carried out to obtain the maximum enzyme activity (2.78 ± 0.145 U ml−1) of recombinant enzyme. The maximum expression of recombinant cellobiohydrolase was obtained at pH 6.0 and 70 °C respectively. Enzyme purification was performed by heat treatment and immobilized metal anionic chromatography. The specific activity of the purified enzyme was 57.4 U mg−1 with 35.17% recovery and 3.90 purification fold. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight of cellobiohydrolase was 78 kDa. Among metal ions, Ca2+ showed a positive impact on the cellobiohydrolase enzyme with increased activity by 115%. Recombinant purified cellobiohydrolase enzyme remained stable and exhibited 77% and 63% residual activity in comparison to control in the presence of n-butanol and after incubation at 80 °C for 1 h, respectively. Our results indicate that our purified recombinant cellobiohydrolase can be used in the biofuel industry.

Synthesis of Ultrahigh Molecular Weight PLAs Using a Phenoxy-Imine Al(III) Complex.

l- and d-lactide polymerization kinetics using phenoxy-imine ligands of the type Me2Al[O-2-tert-Bu-6-(C6F5N=CH)C6H3] in the presence of n-butanol and benzyl alcohol by ring-opening polymerization into polylactide are investigated. Effects of initiator concentration, catalyst concentration, polymerization temperature, and time on the molecular weight of poly-l-lactide are also investigated. Purification and drying of l-lactide are found to significantly influence the polymerization kinetics and the final molecular weight achieved. Ultrahigh molecular weight poly(l-lactic acid) PLLA (Mw = 1.4 × 106 g/mol with Đ = 1.8) and ultrahigh molecular weight poly(d-lactic acid) PDLA (Mw = 1.3 × 106 g/mol with Đ = 2.0) are obtained when polymerization is performed with a molar ratio of monomer to catalyst (LA/Al) of 8000 for 72 h at 120 °C in the presence of benzyl alcohol with conversions of 96 and 91%, respectively. We report for the first time the synthesis of ultrahigh molecular weight poly-l- and d-lactide using the Me2Al[O-2-tert-Bu-6-(C6F5N=CH)C6H3] catalyst. The identified catalyst is found to be suitable for the synthesis of a broad range of molecular weights.

In-situ photopolymerized polyhedral oligomeric silsesquioxane-derived monolithic capillary columns with quinidine functionality for enantioseparation by nano-liquid chromatography.

The successful fabrication of monolithic capillary columns for enantiomer separations was achieved within vinylized fused silica capillaries via fast "one-pot" photo-initiated free radical polymerization reaction. A mixture consisting of polyhedral oligomeric silsesquioxane, O-[2-(methacryloyloxy)ethylcarbamoyl]-10,11-dihydroquinidine was copolymerized in the presence of n-butanol, ethylene glycol and photo-initiator 2,2-dimethoxy-2-phenylacetophenone. The morphology of the resultant polymeric hybrid inorganic-organic material and its permeability as well as porosity can be controlled by adjusting the composition of the monomers and binary porogenic solvent. The chromatographic characteristics of the columns have been investigated. Separation factors of N-acetyl-phenylalanine (Ac-Phe) and dichlorprop dropped with decrease of chiral functional monomer. Permeability was better when the macroporogen ethyleneglycol was present at higher concentrations during the polymerization. In general, the chiral compounds were well separated (dichlorprop: α = 1.53, Rs up to 4.14; Ac-Phe: α = 1.36, Rs up to 2.69) by nano-HPLC with an optimized enantioselective monolithic capillary column which can be prepared within a few minutes.

Acid functionalized coal fly ashes: New solid catalysts for levulinic acid esterification

Coal fly ash (CFA) from different sources (CFA 5, 10, 13) and different size fractions (> or < 75 μm) were characterized and used as inorganic supports for sulfonic acid functionalization by two methodologies including one-pot organosilylation (CFA_CSPTMS) and two-step benzyl alcohol condensation followed by sulfonation (CFA_BnSO3H). The as-prepared organosulfonic CFAs were characterized by solid-state 1H, 13C and 29Si NMR spectroscopy, XPS, S content was quantified by elemental analysis and the intrinsic acidity was determined by potentiometric titration; the highest –SO3H content was obtained for CFA13_BnSO3H. All the functionalized CFAs were tested for the first time as acid solid catalysts in the esterification of levulinic acid (LA) a biomass platform molecule, in the presence of n-butanol. n-Butyl levulinate was the only product with conversions of 100% after 40 min. reaction and using the CFA13_BnSO3H as catalyst. This catalyst also exhibited the highest TOFs (447 h−1) and showed to be the most stable and reusable for 5 consecutive catalytic cycles.

Growth of Pseudomonas taiwanensis VLB120∆C biofilms in the presence of n-butanol.

SummaryBiocatalytic processes often encounter problems due to toxic reactants and products, which reduce biocatalyst viability. Thus, robust organisms capable of tolerating or adapting towards such compounds are of high importance. This study systematically investigated the physiological response of Pseudomonas taiwanensis VLB120∆C biofilms when exposed to n‐butanol, one of the potential next generation biofuels as well as a toxic substance using microscopic and biochemical methods. Initially P. taiwanensis VLB120∆C biofilms did not show any observable growth in the presence of 3% butanol. Prolonged cultivation of 10 days led to biofilm adaptation, glucose and oxygen uptake doubled and consequently it was possible to quantify biomass. Complementing the medium with yeast extract and presumably reducing the metabolic burden caused by butanol exposure further increased the biomass yield. In course of cultivation cells reduced their size in the presence of n‐butanol which results in an enlarged surface‐to‐volume ratio and thus increased nutrient uptake. Finally, biofilm enhanced its extracellular polymeric substances (EPS) production when exposed to n‐butanol. The predominant response of these biofilms under n‐butanol stress are higher energy demand, increased biomass yield upon medium complements, larger surface‐to‐volume ratio and enhanced EPS production. Although we observed a distinct increase in biomass in the presence of 3% butanol it was not possible to cultivate P. taiwanensis VLB120∆C biofilms at higher n‐butanol concentrations. Thereby this study shows that biofilms are not per se tolerant against solvents, and need to adapt to toxic n‐butanol concentrations.

Phospholipase D affects translocation of NPR1 to the nucleus in Arabidopsis thaliana.

Phytohormone salicylic acid (SA) is a crucial component of plant-induced defense against biotrophic pathogens. Although the key players of the SA pathway are known, there are still gaps in the understanding of the molecular mechanism and the regulation of particular steps. In our previous research, we showed in Arabidopsis suspension cells that n-butanol, which specifically modulates phospholipase D activity, significantly suppresses the transcription of the pathogenesis related (PR-1) gene, which is generally accepted as the SA pathway marker. In the presented study, we have investigated the site of n-butanol action in the SA pathway. We were able to show in Arabidopsis plants treated with SA that n-butanol inhibits the transcription of defense genes (PR-1, WRKY38). Fluorescence microscopy of Arabidopsis thaliana mutants expressing 35S::NPR1-GFP (nonexpressor pathogenesis related 1) revealed significantly decreased nuclear localization of NPR1 in the presence of n-butanol. On the other hand, n-butanol did not decrease the nuclear localization of NPR1 in 35S::npr1C82A-GFP and 35S::npr1C216A-GFP mutants constitutively expressing NPR1 monomers. Mass spectrometric analysis of plant extracts showed that n-butanol significantly changes the metabolic fingerprinting while t-butanol had no effect. We found groups of the plant metabolites, influenced differently by SA and n-butanol treatment. Thus, we proposed several metabolites as markers for n-butanol action.

English

A total of 20 bacterial isolates were obtained by screening using tributyrin agar medium. Among them the isolate which exhibited greater clearance zone and higher lipase activity was subsequently screened using spirit blue agar and rhodamine B agar medium. Based on morphological, biochemical and 16S rRNA sequence analysis, the potent isolate was identified as Staphylococcus aureus . The lipase production of the isolate was increased by improving the conditions of production medium. Maximum lipase production (8.11 U/ml) was achieved when 2% punnakka oil was utilized as sole carbon source at pH 7.0 and 37°C after 2 days of incubation. Addition of 3% tryptone as nitrogen source and 0.01% MgCl 2 resulted in a significant increase of lipase production (10.73 U/ml). The lipase production was slightly enhanced in the presence of 20% n-propanol and highly stable in the presence of n-butanol, toluene and n-hexane. The study resulted in isolation and production of inducible, mesophilic and solvent tolerant lipase with industrial potential. Keywords: Staphylococcus sp., tributyrin agar, 16S rRNA , medium optimization, solvent-tolerant lipase. African Journal of Biotechnology , Vol 13(28) 2858-2866

Chemoenzymatic synthesis of piperoxan, prosympal, dibozane, and doxazosin

The synthesis of both enantiomers of 1,4-benzodioxan-2-carboxylic acid 1, a key synthetic intermediate for the therapeutic agents piperoxan, prosympal, dibozane, and doxazosin was achieved with good yields and high enantioselectivities via the Arthrobacter sp. lipase catalyzed kinetic resolution of ester (±)-17a. The influence of the co-solvents and the immobilization of the lipase upon kinetic resolution demonstrated that immobilized whole cells, in the presence of n-butanol as a co-solvent, resulted in the optimal resolution of the substrate (ee ∼99%, E=535) at 258mmol (50g/L) substrate concentration.

Development of cultured microspores of maize in the presence of n-butanol and 2-aminoethanol

The aim of the present study was to examine whether the induction of maize microspore embryogenesis could be triggered by the application of biogenic alcohols, as was reported earlier in wheat. A single cross hybrid (A 18) raised in the phytotron was used as anther donor for shed microspore cultures after cold pretreatment. At the onset of culturing, anthers in liquid YP medium were treated with 0.2 or 0.4% n-butanol or with 2 mM aminoethanol (2-AE) for 6 or 18 hours.The treatments caused a drastic (approx. 50%) decrease in the viability of the microspores. After a few days of culture in medium containing neither n-butanol nor 2-AE, 9-13% of the microspores remained alive and capable of switching to the sporophytic pathway of development.Treatment with 0.2% n-butanol for 6 h considerably increased the frequency of symmetric nuclear divisions (more than 3×) and of induced microspores (2×). The embryo yield was also elevated by 10%. The results showed that n-butanol could be used to improve the androgenic response and microspore embryogenesis in maize, but not as efficiently as in wheat. Further examination will be required to find the reasons for the different behaviour of microspores of the two species.

Acyl Chains of Phospholipase D Transphosphatidylation Products in Arabidopsis Cells: A Study Using Multiple Reaction Monitoring Mass Spectrometry

BackgroundPhospholipases D (PLD) are major components of signalling pathways in plant responses to some stresses and hormones. The product of PLD activity is phosphatidic acid (PA). PAs with different acyl chains do not have the same protein targets, so to understand the signalling role of PLD it is essential to analyze the composition of its PA products in the presence and absence of an elicitor.Methodology/Principal findingsPotential PLD substrates and products were studied in Arabidopsis thaliana suspension cells treated with or without the hormone salicylic acid (SA). As PA can be produced by enzymes other than PLD, we analyzed phosphatidylbutanol (PBut), which is specifically produced by PLD in the presence of n-butanol. The acyl chain compositions of PBut and the major glycerophospholipids were determined by multiple reaction monitoring (MRM) mass spectrometry. PBut profiles of untreated cells or cells treated with SA show an over-representation of 160/18∶2- and 16∶0/18∶3-species compared to those of phosphatidylcholine and phosphatidylethanolamine either from bulk lipid extracts or from purified membrane fractions. When microsomal PLDs were used in in vitro assays, the resulting PBut profile matched exactly that of the substrate provided. Therefore there is a mismatch between the acyl chain compositions of putative substrates and the in vivo products of PLDs that is unlikely to reflect any selectivity of PLDs for the acyl chains of substrates.ConclusionsMRM mass spectrometry is a reliable technique to analyze PLD products. Our results suggest that PLD action in response to SA is not due to the production of a stress-specific molecular species, but that the level of PLD products per se is important. The over-representation of 160/18∶2- and 16∶0/18∶3-species in PLD products when compared to putative substrates might be related to a regulatory role of the heterogeneous distribution of glycerophospholipids in membrane sub-domains.

Using PVP-SDS Complex as a Probe to Study the Effect of n-Butanol on Micellization Behavior of SDS

PVP[poly(vinyl pyrrolidone)]/SDS(sodium dodecyl sulfate) complex was applied as a probe to study the effect of n-butanol on micellization behavior of SDS. It has been found that a critical concentration, namely cs, exists in the relative viscosity versus n-butanol concentration plot. As the n-butanol concentration is less than cs, the relative viscosity of solution containing PVP/SDS complex increased by adding n-butanol into solution successively. On the other hand, as the n-butanol concentration is greater than cs, the relative viscosity of solution containing PVP/SDS complex decreased by adding n-butanol into solution. The increase and the decrease of the relative viscosity of solution containing PVP/SDS complex in the presence of n-butanol is just due to the cosurfactant and the cosolvent effect on micellization behavior of SDS in aqueous solution. Further experimental results indicate that cs is dependent on SDS concentration.

Low Energy Ion Scattering Investigations of n-Butanol−Ice System in the Temperature Range of 110−150 K

We have investigated the interaction of n-butanol (NBA) with thin layers of water ice prepared in ultra high vacuum in the temperature range of 110−150 K. From the mass spectra of the chemically sputtered species, created upon the collision of low energy (≥30 eV) Ar+ ions, we study the process of diffusive mixing of NBA with water ice, at the molecular level. The results show that NBA undergoes diffusive mixing with H2O. Even after depositing 1000 monolayers (MLs) of amorphous solid water (ASW) over NBA, both the species are observed on the surface. However, when NBA is deposited over ASW, no water is seen on the surface above 3−5 MLs of NBA. This could be interpreted as the absence of diffusive mixing in this system or surface segregation of NBA, in view of its lower surface energy just as in the case of liquid alcohols. An isomeric alcohol, namely, tert-butyl alcohol (TBA), also behaves similarly. Although the presence of NBA and TBA is detected, in the presence of ASW, they undergo selective ionization, giving specific peaks in the mass spectrum. D2O behaves in a manner similar to that of H2O. Preliminary experiments with other alcohols; namely, methanol, ethanol, and propanol were also done, and the results suggest that incomplete diffusion or surface segregation begins with propanol.

Modulatory role of phospholipase D in the activation of signal transducer and activator of transcription (STAT)-3 by thyroid oncogenic kinase RET/PTC

BackgroundRET/PTC (rearranged in transformation/papillary thyroid carcinomas) gene rearrangements are the most frequent genetic alterations identified in papillary thyroid carcinoma. Although it has been established that RET/PTC kinase plays a crucial role in intracellular signaling pathways that regulate cellular transformation, growth, and proliferation in thyroid epithelial cells, the upstream signaling that leads to the activation of RET/PTC is largely unknown. Based on the observation of high levels of PLD expression in human papillary thyroid cancer tissues, we investigated whether PLD plays a role in the regulating the RET/PTC-induced STAT3 activation.MethodsCancer tissue samples were obtained from papillary thyroid cancer patients (n = 6). The expression level of PLD was examined using immunohistochemistry and western blotting. Direct interaction between RET/PTC and PLD was analyzed by co-immunoprecipitation assay. PLD activity was assessed by measuring the formation of [3H]phosphatidylbutanol, the product of PLD-mediated transphosphatidylation, in the presence of n-butanol. The transcriptional activity of STAT3 was assessed by m67 luciferase reporter assay.ResultsIn human papillary thyroid cancer, the expression levels of PLD2 protein were higher than those in the corresponding paired normal tissues. PLD and RET/PTC could be co-immunoprecipitated from cells where each protein was over-expressed. In addition, the activation of PLD by pervanadate triggered phosphorylation of tyrosine 705 residue on STAT-3, and its phosphorylation was dramatically higher in TPC-1 cells (from papillary carcinoma) that have an endogenous RET/PTC1 than in ARO cells (from anaplastic carcinoma) without alteration of total STAT-3 expression. Moreover, the RET/PTC-mediated transcriptional activation of STAT-3 was synergistically increased by over-expression of PLD, whereas the PLD activity as a lipid hydrolyzing enzyme was not affected by RET/PTC.ConclusionThese findings led us to suggest that the PLD synergistically functions to activate the STAT3 signaling by interacting directly with the thyroid oncogenic kinase RET/PTC.

Gas Phase Hydrogenation of Maleic Anhydride to γ-Butyrolactone by Cu–Zn–Ce Catalyst in the Presence of n-Butanol

A series of Cu–Zn–Ce catalysts were prepared by coprecipitation method and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, temperature programmed reduction, and N2 adsorption. The catalytic activities of the Cu–Zn–Ce catalysts in gas phase hydrogenation of maleic anhydride in the presence of n-butanol were studied at 220–280 °C and 1 MPa. The conversion of maleic anhydride was more than 97%. After reduction, CuO species present in the calcined Cu–Zn–Ce catalysts were converted to metallic copper (Cu°). The presence of ZnO in the Cu–Zn–Ce catalysts was beneficial to stabilizing the catalytic activity in maleic anhydride hydrogenation to γ-butyrolactone. At the same time, n-butanol was dehydrogenated to butyl aldehyde, then to butyl butyrate via reactions, such as disproportionation and esterification. Cu–Zn–Ce catalysts are beneficial to the H2 compensation in the coupling process of hydrogenation and dehydrogenation.

Gas phase hydrogenation of maleic anhydride to tetrahydrofuran by Cu/ZnO/TiO2 catalysts in the presence of n-butanol

Abstract Cu/ZnO/TiO 2 catalysts were prepared via the coprecipitation method. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectrometry, temperature programmed reduction, and N 2 adsorption. The catalytic activity of Cu/ZnO/TiO 2 catalyst in gas phase hydrogenation of maleic anhydride in the presence of n -butanol was studied at 235–280 °C and 1 MPa. The conversion of maleic anhydride was more than 95.7% and the selectivity of tetrahydrofuran was up to 92.7%. At the same time, n -butanol was converted to butyraldehyde and butyl butyrate via reactions, namely, dehydrogenation, disproportionation, and esterification. There were two kinds of CuO species present in the calcined Cu/ZnO/TiO 2 catalysts. At a lower copper content, the CuO species strongly interacted with ZnO and TiO 2 ; at a higher copper content, both the surface-anchored and bulk CuO species were present. The metallic copper (CuO) produced by the reduction of the surface-anchored CuO species favored the deep hydrogenation of maleic anhydride to tetrahydrofuran. The deep hydrogenation activity of Cu/ZnO/TiO 2 catalyst increased with the decrease of crystallite sizes of CuO and the increase of microstrain values. Compensations of reaction heat and H 2 in the coupling reaction of maleic anhydride hydrogenation and n -butanol dehydrogenation were distinct.

N -Butanol induces depolymerization of microtubules in vivo and in vitro

The effects of butanol on microtubules (MTs) were examined by immunofluorescence microscopy. Fragmentation of cortical MTs was induced by n-butanol, but not by s- and t-butanols, in cultured tobacco BY-2 cells. Taxol prevented n-butanol-induced MT fragmentation. Fragmented cortical MTs were still attached to the inner face of the plasma membrane when n-butanol-treated protoplasts were ruptured on the slide glass. Moreover, MTs were depolymerized in the presence of n-butanol in vitro. Therefore, n-butanol is not only an activator of phospholipase D but also an effective MT-depolymerizing agent.

Do sperm contribute to the buffering capacity of steelhead trout ( Oncorhynchus mykiss) semen?

The motility of salmonid sperm is pH-sensitive and the buffering capacity of the seminal plasma is low. The objective of the present study was to determine the extent to which sperm contribute to the buffering capacity of whole steelhead ( Oncorhynchus mykiss) semen. To determine the buffering capacity, semen and seminal plasma samples were titrated with HCl and pH measurements taken at 1–2 min. The buffering capacity of semen was not different from that of seminal plasma over the pH range 7.5 to 8.5 and was approximately 15% to 20% less over the range 6.0 to 7.0. Comparable results were obtained for the semen and seminal plasma of the chinook salmon ( Oncorhynchus tshawytscha). To assess whether the intracellular environment could influence the buffering capacity, the effects of cell disruption with n-butanol and Triton X-100 (TX-100) were determined. Over the pH range 7.5 to 8.5, the presence of n-butanol or TX-100 resulted in a doubling of the buffering capacity of the semen; TX-100, but not n-butanol, increased semen buffering capacity over the pH range 6.0 to 7.0. To determine whether the sperm's intracellular compartment might contribute to the buffering capacity over a longer duration, semen and seminal plasma samples were acidified with HCl and the pH measured over several hours. These data suggest that intact sperm contribute no more than about 25% to the buffering capacity of whole semen. The buffering capacity of steelhead semen and seminal plasma were comparably and modestly temperature sensitive. The results suggest that the sperm may contribute to the buffering capacity of the semen over a physiological pH range, however, if so, the effect is relatively small.

Kinetics of microemulsion copolymerization of styrene and acrylonitrile in the presence of cosurfactant

The kinetics of microemulsion copolymerization of styrene and acrylonitrile in oil-in-water microemulsions in the presence of n-butanol as a cosurfactant was investigated. Stable and translucent poly(styrene- co-acrylonitrile) latexes were produced. The variations of initiator concentration, polymerization temperature, monomer feed composition and cosurfactant concentration in the microemulsion copolymerization were studied. In addition, the particle size and molecular weights of copolymerization products were characterized. It was found that the rate of copolymerization decreases pronouncedly and the maximum rate was shifted to a lower conversion with an increase of AN concentration in the monomer feed. The presence of n-butanol can lead to a decrease in polymerization rate and an increase in particle size, but a complex effect on the molecular weight of the copolymer. The obtained experimental results were discussed in terms of the nucleation mechanism, the agglomeration of particles and the effect of microemulsion structure.