Experimental investigation of foam performance in the presence of crude oil

The foam performance in the presence of oil plays an important role in foam application in enhancing oil recovery. The present study systematically investigated the effect of oil type, oil content, surfactant type, surfactant concentration, alkane chain length, salinity, and polymer concentration on foam performance in both the absence and presence of oil. The results showed that oil viscosity and oil density as well as oil component all contributed to foam performance in the presence of oil. Within a certain oil content, both light oil and heavy oil had a positive effect on foam, but heavy oil had a higher tendency to stabilize the foam. The order of foam performance by different surfactants was changed by the oil. It is noteworthy that heavy oil is detrimental to sodium dibutyl naphthalene sulfonate (BM) foam. Light oil can improve foam performance while heavy oil can harm foam in some specific cases. Lower salinity, longer alkane chain length, higher surfactant concentration and the presence of a polymer all benefited foam in the presence of crude oil.     

Oxidative degradation properties of Co-based catalysts in the presence of ozone

Four series of cobalt-based catalysts, such as bare Co₃O₄ and CoO, CoO_x–CeO₂ mixed oxides, CoO_x supported over alumina and alumina–baria and CoMgAl and CoNiAl hydrotalcites have been synthesized and investigated for the oxidative degradation of phenol in the presence of ozone. Characterizations were obtained by several techniques in order to investigate the nature of cobalt species and their morphological properties, depending on the system. Analyses by XRD, BET, TPR, UV–visible diffuse reflectance spectroscopy and TG/DT were performed.

The CoNiAl hydrotalcite exhibits, after 4 h of reaction, the highest phenol ozonation activity followed by Co(3 wt%)/Al₂O₃–BaO and CoMgAl. The samples Co(1 wt%)/Al₂O₃–BaO and Co(1 and 3 wt%)/Al₂O₃ show a comparable medium activity, while the oxidation properties of bare oxides Co₃O₄, CoO and CoO_x–CeO₂ are really low. Leaching of cobalt ions in the water solution was detected during the reaction, the amount varied depending on the nature of catalysts. A massive release was observed for the CoMgAl and CoNiAl hydrotalcites, while cobalt catalysts over alumina and alumina–baria look much more stable. The recycle of CoO_x/Al₂O₃ and CoO_x/Al₂O₃–BaO was studied by performing three consecutive cycles in the phenol oxidation. Because of the potential interest of the cobalt-supported catalysts in the ozonation process, the oxidative degradation of naphtol blue black was also investigated.

On the basis of TPR and UV–visible results it appears that highly dispersed Co²⁺ ions especially present over Co(3 wt%)/Al₂O₃–BaO are the main active sites for phenol and naphtol blue black oxidative degradation by ozone.     

Influences of rice hull in polyurethane foam on its sound absorption characteristics

In this article, rice hull (RH) was used in the moulding of polyurethane (PU) foam system. The article analyzed the participation of RH in the chemical reaction of PU synthesis with Attenuated Total Reflection‐Fourier Transform Infrared spectroscopy method. Besides, the influence of RH on the formation of pore structure along with the acoustic performance such as sound impedance rate, acoustic reflection factor, sound absorption coefficient, and transmission loss of the products were studied with the Transfer Function Method. The results indicated that RH significantly influenced the uniformity of pore diameter in PU foam. As the content of RH increased, the sound absorption peak shifted toward lower frequency region. And the sound absorption coefficients increased till a threshold value of RH content. POLYM. COMPOS., 34:1847–1855, 2013. © 2013 Society of Plastics Engineers     

丙三醇水蒸气重整制氢M/Al2O3催化剂

以Al2O3为载体,采用浸渍法制备了Cu、Co、Ni、Pt/Al2O3四种单一组分催化剂(M/Al2O3)。研究了M/Al2O3催化剂对丙三醇水蒸气重整制氢反应的适用性及反应行为;考察了制备条件及还原条件,通过活性、稳定性及抗积炭性进行了催化剂的活性评价,并对催化剂进行了TPR、XRD表征。研究发现M/Al2O3催化剂用于丙三醇水蒸气重整制氢均表现出一定活性;其中Cu/Al2O3催化剂具有一定的抗积炭性;Pt/Al2O3催化剂表现出较好的抗积炭性、高温活性,但稳定性较差;Co/Al2O3催化剂表现出较好的稳定性;Ni/Al2O3催化剂表现出较好的低温活性。     

聚氨酯板材HCFC-141b替代技术及配套的泡沫稳定剂和催化剂发展现状

介绍了我国聚氨酯板材子行业在聚氨酯泡沫行业第一阶段淘汰目标完成和第二阶段HCFCs(含氢氯氟烃)替代工作已启动的情况下,HCFC—141b(一氟二氯乙烷)替代技术的应用情况及与替代技术相配套的泡沫稳定剂和催化剂的应用现状,阐述了泡沫稳定剂和催化剂开发重点。     

Study of the structure of foam glass with different characteristics

The results of a study of the micro-and macroscopic structure of foam glass with different characteristics are reported.     

Simultaneous removal of Pb(II) and chemical oxygen demand from aqueous solution using immobilized microorganisms on polyurethane foam carrier

We studied the simultaneous removal of Pb(II) and chemical oxygen demand (COD) from synthetic solutions using immobilized microorganism. The immobilized microorganisms on polyurethane foam (IPUF) were successfully prepared by cultivating the microbe B350 in a mixture of culture medium and polyurethane foam (PUF). The adsorption of Pb(II) ion from aqueous solutions onto PUF and IPUF was studied by batch adsorption. IPUF exhibited high Pb(II) removal efficiency. When 0.12 g of IPUF was used to treat 50mL of 20mg/L P(II) solution at pH 7.0 and 25 °C for 120 mins, the removal ratio was 80%. The biosorption kinetics could be described by the pseudo-secondorder model, and the adsorption isotherms could be described by Langmuir and Freundlich equations. In addition, for synthetic wastewater containing Pb(II) and C₆H₁₂O₆, the removal ratios of Pb(II) and COD after being treated by IPUF for 8 hours were 92.0% and 84.2%, respectively. The removal ratio of COD clearly decreased with the increase of Pb(II) concentration, meaning that Pb(II) was toxic to the mobilized microorganisms and lower Pb(II) concentration was preferred.     

Use of inverse gas chromatography to assess the compatibility of polyurethane foam with liquids at different temperatures

A crosslinked polyurethane foam has been used as the stationary phase in inverse gas chromatography to measure the solubility parameter (δ₂) of the polymer at several temperatures (T) within the range 298–383 K. Values of δ₂ = 29.5(MPa)^1/2 at 298K and dδ₂/dT = ?0.06(MPa)^1/2 K^?1 were yielded. Linear decreases with temperature of the solubility parameters (δ₁) of water, ethanol and methanol were obtained by calculation from relevant properties of the liquids. The results were used to assess the conditions for the polyurethane foam to act as a non-interacting barrier against liquids of different polarities for which the criterion is that |δ₁ ? δ₂| should be large. The findings highlight the need to consider both the nature of the liquid and the temperature regime.     

泡沫塑料法在高浓度盐酸溶液中吸附回收锗

研究了用聚氨酯泡沫塑料吸附分离富集微量锗的性能。结果表明,在盐酸溶液中泡塑对微量锗具有显著的吸附性能,最佳吸附条件为:盐酸浓度10 mol/L,泡塑与含锗溶液的固液比为1 g/50 mL,吸附时间1 h,吸附率可达80%,可获得最大吸附量为6.056 mg/g。实验发现,在铁离子共存下,锗的吸附效率明显有所提高,共存离子铁离子能起到协助吸附效应。     

Biodegradation of chlorophenols using the cell‐free culture broth of Phanerochaete chrysosporium immobilized in polyurethane foam

A cell‐free culture broth of Phanerochaete chrysosporium immobilized in polyurethane foam has been evaluated for the biodegradation of chlorophenols. Lignin peroxidase, manganese peroxidase, and oxalate concentrations in cell‐free culture broth were measured and compared to find the optimum combination of secondary metabolites for the highest biodegradation of chlorophenols. The isozyme distributions and their expression levels were significantly different and changed with increases in the culture time. The oxalate concentration was also found to vary, depending on culture time. Cell‐free broth containing an optimal combination of secondary metabolites showed the greatest biodegradation of 2,4,5‐chlorophenol in the presence of veratryl alcohol and H₂O₂. Phenols with greater numbers of chlorines were degraded more efficiently by this cell‐free culture broth according to the results of biodegradation experiments for five chlorophenols, including 2‐, 4‐, 2,4‐, 2,4,5‐, and pentachlorophenol, as well as phenol. This degradation efficiency correlated well with remaining lignin peroxidase activity during degradation. Cell‐free culture broths may readily be used for biodegradation of highly recalcitrant chemicals since the system would not be affected by the toxicity of the chemicals nor would the adsorption characteristics of the cells be of concern. © 2002 Society of Chemical Industry     

Water-dispersed polypyrrole nanoparticles via chemical oxidative polymerization in the presence of a functional polyanion

Poly(2-hydroxy-3-(methacryloyloxy) propane-1-sulfonate) (PHMPS), a polyhydroxyl sulfonate, was used as both the template and the dopant in the in situ doping chemical oxidative polymerization of pyrrole. The resultant PHMPS doped polypyrrole (PPy/PHMPS) nanoparticles were characterized with FTIR, UV–vis, TGA, zeta potentials and TEM techniques. It was found that their size decreased and their dispersing stabilities in water increased with the increasing of the feeding ratio of PHMPS. The PPy/PHMPS nanoparticles possess high electrical conductivity at room temperature and the weak temperature dependence of the conductivity. The conductivity–temperature heating curves are discussed.     

Effects of different catalysts on the structure and properties of polyurethane/water glass grouting materials

Polyurethane/water glass (PU/WG) grouting materials were prepared in presence of different proportions of catalyst. The effects of catalyst on the mechanical properties, thermal properties, and chemical cross‐sectional morphologies of the grouting materials were also investigated. Catalyst addition can significantly increase the chemical reaction rate, reduce the gel time and curing time, and improve the thermal stability of PU/WG grouting materials. It was found that the grouting material containing 0.1 wt % BDMA + 0.1 wt % DBTDL demonstrated high fluidity, short curing time, and high early‐stage and late‐stage (up to 66.1 MPa) compression strengths. However, when the content of the added catalyst was equal to 0.5 wt %, fine cracks were formed in the material structure accompanied by the detachment of spherical particles from the PU matrix, which significantly deteriorated its mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46460.     

Use of gas-liquid chromatography in the analysis of rigid polyurethane foam polyols

Detailed characterization of the low molecular weight polyols used as intermediates in rigid polyurethane foam production has not been feasible to date. Gas-liquid chromatography of the trimethylsilyl ether derivatives of the polyols now offers a more complete picture of polyol composition, particularly with regard to the molecular weight distribution. The data may be interpreted on a semiquantitative basis. The study of processing variables in polyol manufacture, detection of impurities and analysis of unknown polyols or those based on mixed initiators may all be facilitated by use of this GLC technique.     

Hydraulic resistance of rigid polyurethane foams. III. Effect of variation of the concentration of catalysts on foam structure and properties

Water blown rigid polyurethane foams are made using dibutyltin dilaurate and triethanol amine as catalysts. The rate of carbon dioxide generation due to the reaction of isocyanate with water and the rate of polymerization are varied by changing the relative proportion of the catalysts keeping the total catalyst concentration fixed. The foams have densities in the range of 134 to 164 kg/m³. Foams are characterized for hydraulic resistance, “closed cell content,” and compressive modulus. A cell window is the lamella of the foam material that separates two adjacent cells. A strut is generated where three windows of three different cells meet. The cell window area and strut width of the foam cells are measured by optical microscopy. It is found that cell window area and strut width decrease and the respective distribution becomes narrower as the proportion of dibutyltin dilaurate in the total amount of the catalysts is increased. The hydraulic resistance and hence threshold pressure of the foams increases with increase in the proportion of dibutyltin dilaurate. The maximum threshold pressure of 1.81 MPa is observed for the foam made with dibutyltin dilaurate alone. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2838–2843, 2004     

Preparation,characterization and dielectric properties of polycyanurate films cyclotrimerized in the presence of different catalysts

The article deals with the preparation and characterization of a series of functional polycyanurate (PCN) films obtained from bisphenol E dicyanate (BDECy) by thermal cyclotrimerization in the presence of four different catalysts. Thermal, structural, and dielectrical analyses of PCN films are performed as well as some physical properties such as solubility, adhesion, hardness, and contact angle measurements are studied. Fourier transform infrared spectroscopy results reveal that cyclotrimerized structure is formed from BDECy not only in the presence of catalyst but also free of catalyst. While 55.5% of BDECy is cylotrimerized without catalyst, the conversion of BDECy into triazine significantly increases and reaches to 82.1% and 84.8% for PCNPh1‐2 and PCNPh3‐2, respectively. Thermogravimetric analysis results reveal that PCN films prepared in the presence of catalyst are thermally stable up to 240°C and exhibit two degradation steps. Dielectric constant and dielectrical breakdown strength of the PCN film cyclotrimerized with 1 wt% phenol as catalyst are found to be 3.16 at 1 MHz and 194 kV/mm, respectively, while the catalyst‐free PCN film has the dielectric constant of 4.92 at the same frequency. On the other hand, chemical stability, hardness, and adhesion properties of the prepared films are found to be excellent. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers.     

Rheological analysis of the degradation of HDPE during consecutive processing steps and for different processing conditions

Using a twin‐screw extruder, HDPE has been processed six times consecutively under a range of processing conditions (changing barrel temperature, screw speed, and feed rate). After each pass, the product has been analyzed in terms of the melt flow index (MFI) and G_C(ω_C), the crossover point of the viscoelastic moduli as a function of the angular velocity at which it occurs. MFI data show changes in the structure of the HDPE after each processing step, but this information is limited in quality and quantity. G_C data show the mechanism for degradation (side‐chain branching and chain scission) and allow us to track relative changes in mean molecular weight (MMW) and molecular weight distribution (MWD). MMW and MWD both increase as a result of continued reprocessing. The apparent changes in MWD are substantial indicating significant chain scission initially, accompanied and followed during subsequent processing by a combination of side‐chain branching and further chain scission. A relative measure of the polydispersity index (PI) of the melt is calculated and the PI increases as the HDPE is further reprocessed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009