Synthesis and properties of novel fluorescent‐tagged polyacrylate‐based scale inhibitors

The two fluorescent monomers N ‐allyl‐4‐methoxy‐1,8‐naphtalimide ( F1 ) and N ‐allyl‐2‐(6‐hydroxy‐3‐oxo‐3H ‐xanthen‐9‐yl)benzamide (N ‐allylamidefluorescein, F2 ) have been synthesized and then conjugated to either polyacrylate (PAA) or to a co‐polymer of fumaric and acrylic acids (MA‐AA) to give four novel fluorescent‐tagged antiscalants: nonbiodegradable PAA‐F1, PAA‐F2 and biodegradable MA‐AA‐F1 , MA‐AA‐F2 . All four reagents demonstrate the fluorescence intensity suitable for inhibitors monitoring with a detection limit within 0.40 mg dm^?3. A good linear relationship between antiscalant fluorescent intensity and its dosage is detected. PAA‐F1, PAA‐F2, MA‐AA‐F1, and MA‐AA‐F2 can be used for corresponding scale inhibitor content on‐line measurement. For some antiscalants, the fluorescence is found to be dependent on the background heavy metal ions normally present in the cooling water. This effect is explained by the corresponding complexes formation. PAA‐F1, PAA‐F2, MA‐AA‐F1, and MA‐AA‐F2 revealed a good antiscaling activity toward CaCO₃ and CaSO₄ deposition, comparable with that one of commercial polyacrylates. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45017.     

Melt processable and biodegradable aliphatic polycarbonate derived from carbon dioxide and propylene oxide

Alternating poly(propylene carbonate)s (PPC)s were successfully synthesized from carbon dioxide and propylene oxide in higher yield than previously reported. Such thermally stable and high molecular weight copolymers were achieved by optimizing the reaction conditions. The molecular structural change and mechanical properties of the alternating copolymer subjected to melt extrusion were examined by means of modulated differential scanning calorimetry (MDSC), thermogravimetric analysis (TGA), NMR, and tensile tests. The MDSC and TGA results showed that the alternating copolymer generally exhibits a high glass‐transition temperature of above 40°C and a decomposition temperature of above 250°C. These PPCs can be readily melt processed under conditions similar to those for commercial polyolefins. For instance, they can be melt extruded in a temperature range from 150 to 170°C under varying extrusion pressures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3301–3308, 2003     

Synthesis and degradation behavior of poly(propylene carbonate) derived from carbon dioxide and propylene oxide

High molecular weight and regular molecular structure poly(propylene carbonate) (PPC) was successfully synthesized from carbon dioxide and propylene oxide. The PPC copolymer structure was an exact alternating copolymer as evidenced by the ¹³C‐NMR technique. Degradative behavior of the PPC was conducted by soil burial and buffer solution immersion (pH = 6) tests, respectively. The results showed that the weight loss of soil buried in PPC films increased more slowly than that immersed in the buffer solution after 6‐month exposure. However, the weight loss of sample immersed in the buffer solution increased rapidly during the first 2 months and reached a value of 4.59%. Water sorption measurement also revealed that the PPC membranes immersed in buffer solution were more hydrophilic than those in soil burial tests. The degradation mechanism of PPC membranes was correlated with the sample morphologies, FTIR, and ¹H‐NMR spectra. The SEM morphologies were consistent with the weight loss and water sorption measurements. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1840–1846, 2004     

Mechanisms of carbon dioxide laser stereolithography in epoxy-based materials

We present in this article the use of infrared laser radiation to achieve localized curing in thermosensitive epoxy resin compounds. In stereolithography, the objective is to cure a localized region in a material by precisely confining the laser energy to the area that is to be cured. Industry already uses ultraviolet laser radiation at 352 nm to fabricate three-dimensional structures. Via infrared laser curing, we demonstrate the viability of a completely thermal localized curing process. In our experiment, we have focused the beam from a carbon dioxide (CO₂) laser onto a sample composed of epoxy resin, diethylene triamine, and silica powder. Such resins typically cure, or solidify, when heated to moderately high temperatures, and our results show that we can confine the heating of the material, and, therefore, its curing in all three dimensions. We present a physical and a chemical model to describe the process and measure the curing rate as a function of temperature. In order to model the flow of heat in our sample as a result of infrared laser irradiation, we solved the time-dependent heat equation in cylindrical coordinates using the Crank-Nicholson finite-difference method. The results allow us to predict the curing behavior of the sample as a function of laser irradiation conditions, and we find good agreement with our preliminary experimental observations. © 1996 John Wiley & Sons, Inc.     

Synthesis and characterization of modified poly(aspartic acid) and its performance as a formaldehyde adsorbent

A modified poly(aspartic acid) (PASPTU) as an efficient formaldehyde adsorbent is successfully prepared by grafting poly(aspartic acid) (PASP) with threonine and urea. The graft copolymer is characterized by means of nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. Its formaldehyde adsorbent property is measured. The optimal adsorption process is as follows: synthesis temperature was 40 °C, molar ratio of PSI, threonine, and urea was 1:0.6:0.4 and adsorption time was 3.0 h. In above condition, the formaldehyde adsorbent efficiency of the copolymer was nearly 100% when the PASPTU dosage was 0.5 g. The Langmuir and Freundlich adsorption isotherms are used to study the adsorption process of formaldehyde. The findings show that PASPTU has excellent formaldehyde adsorbent efficiency. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45798.     

Green polycarbonates prepared by the copolymerization of CO2 with epoxides

Polycarbonates can be prepared by the copolymerization of epoxides with carbon dioxide as an inexpensive, abundant, nontoxic, and renewable feedstock. This review covers the synthesis, the physicochemical properties, and the growing applications of this class of green polymers. The review has been conceived to provide a useful tool for the researchers who are new to this field, as well as to offer an updated overview for those who are already actively working on this topic. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41141.     

Preparation of carbon dioxide/propylene oxide/ε-caprolactone copolymers and their drug release behaviors

Summary Poly (propylene-ram-ε-caprolactone carbonate) (PPCL) and poly (propylene carbonate) (PPC) were synthesized by ring-opening copolymerization from carbon dioxide, propylene oxide (PO) and ε-caprolactone (CL) using a polymer-supported bimetallic complexes (PBM) as catalyst. PPC and PPCL microspheres containing a 5-alpha reductase inhibitor, finasteride were elaborated by a conventional oil-in-water (O/W) emulsion-solvent evaporation method. The effects of polymer used on microspheres morphology, size, drug loading, encapsulation efficiency and drug release behaviors were examined. In vitro drug release of these microcapsules was performed in a pH 7.4 phosphate-buffered solution. A prolonged in vitro drug release profile was observed. The release profiles of finasteride from PPC and PPCL microcapsules were found to occur with a burst release followed by a gradual release phase. Drug release rates were dependent upon the properties of the polymer in the microspheres, the higher hydrolytic activity of polymer provided faster release rate.     

Copolymerization of carbon dioxide and epoxides with a novel effective Zn–Ni double‐metal cyanide complex

A novel double‐metal cyanide complex based on Zn[Ni(CN)₄] was prepared and used as a catalyst for the copolymerizations of carbon dioxide and propylene oxide (PO) and carbon dioxide and cyclohexene oxide (CHO). The copolymers were characterized by IR and ¹H‐NMR, and the effects of temperature, pressure, solvent, and preparative methods for the catalysts on catalytic activity and composition of the copolymer were investigated. The results show that this novel catalyst exhibited its highest catalytic efficiency at about 500 g/g of Zn[Ni(CN)₄] for PO and CO₂, whereas the catalytic efficiency for CHO and CO₂ was merely between 5.6 and 22.5 g/g of Zn[Ni(CN)₄]. The molar fraction of carbonate linkages for PO–CO₂ and CHO–CO₂ copolymers reached about 0.6 and 0.3, respectively. The results show that a lower temperature and a higher CO₂ pressure were favorable for the incorporation of CO₂ into the copolymer, and the nonpolar solvents were better media for copolymerization. As a complexing agent, glycol ether exhibited better promoting effects on catalytic efficiency among those investigated, but the catalysts prepared by different complexing agents showed no significant differences in the compositions of the copolymers. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

High-viscoelastic graft modified chitosan hydrophobic association polymer for enhanced oil recovery

The conventional partially hydrolyzed polyacrylamide (HPAM) is greatly restricted by its single linear molecular structure in oil reservoirs with severe reservoir conditions such as high temperature and high salt. In this article, the chitosan (CS) grafted imidazoline monomer copolymer (CS-g-AM/AA/NIDA) was prepared from N-maleyl CS (N-MCS), acrylamide (AM), acrylic acid (AA), 1-(2-N-acryloylaminoethyl)-2-oleoyl imidazoline (NIDA) by free radical copolymerization. The structure was determined by means of Fourier transform infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy, scanning electron microscope, thermal gravimetric analysis, and so forth, which confirmed the successful preparation of the copolymer with good thermal stability. Under the same conditions, compared with HPAM and copolymer CS-g-AM/AA, CS-g-AM/AA/NIDA greatly increased the viscosity of the aqueous solution and exhibited excellent shear stability (viscosity retention rate 15.62, 4.91, and 11.54% at 510 s⁻¹), temperature resistance (the viscosity retention rate reached 50.89, 24.50, and 36.59% at 120°C) and salt resistance (14,000 mg/L NaCl: viscosity retention rate up to 17.27, 8.26, and 14.60%). In addition, core flooding experiments showed that oil recovery could be enhanced by up to 8.08% by CS-g-AM/AA/NIDA. As a natural polymer material, CS has hardly been reported for polymer flooding, and it is expected to replace general polymers in tertiary oil recovery.     

Amino-functionalized magnetic zirconium alginate beads for phosphate removal and recovery from aqueous solutions

Amino-functionalized magnetic zirconium alginate beads with an interpenetrating network (Fe₃O₄/PAM/SA–Zr) were prepared, characterized, and then tested as a novel biomass adsorbent for phosphate removal and recovery. The hydrogel beads exhibited outstanding thermostability and possessed a magnetic response. The effects of the pH, dosage, initial phosphate concentration, interference ions, and temperature on the removal of phosphate were investigated. The kinetics, isotherms, and thermodynamics of the adsorption were studied. Notably, the adsorption of phosphate was endothermic, feasible, and spontaneous with a maximum uptake capacity of 42.23 mg-P/g at an optimized pH of 2.0. The phosphate could be desorbed effectively with a 0.2 mol/L NaOH solution, and the adsorbent exhibited a good reusability. The possible adsorption mechanisms were verified by zeta potential, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses. Continuous phosphate-adsorption tests were conducted in a fixed-bed columns packed with Fe₃O₄/PAM/SA–Zr, and the breakthrough curves were predicted by the Adams–Bohart, Thomas, and Yoon–Nelson models, respectively. The suitability of the hydrogel beads for the treatment of real wastewater was also tested. These hydrogel beads should be a promising adsorbent for phosphate removal and recovery from aqueous solutions, with the advantages of a high uptake capacity, good reusability, and easy magnetic separation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46897.     

Synthesis,characterization and application of novel polyacrylamide‐grafted barley

Polyacrylamide‐grafted barley (BAR‐g‐PAM) was synthesized by ceric ion‐based conventional method. The grafting of polyacrylamide chains on the polysaccharide backbone was confirmed through various physicochemical techniques such as intrinsic viscosity measurement, ¹³C‐NMR spectra, FTIR spectroscopy, elemental analysis, scanning electron microscopy morphology, thermogravimetric analysis study, number‐average molecular weight, and aqueous solubility. Furthermore, flocculation efficacy of the graft copolymers was studied in coal fine suspension through “jar test” procedure, toward its possible application as a novel flocculant for treatment of coal washery effluent. BAR‐g‐PAM is reported as a novel flocculant that can be used for bulk treatment of coal washery effluents. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41046.     

Preparation and characterization of graft copolymer from dealkaline lignin and styrene

Graft copolymerization of styrene onto dealkaline lignin by ferrous chloride and hydrogen peroxide coinitiator has been achieved successfully. The influence of temperature and reaction time as well as the amount of the styrene monomer, initiator, and catalyst on the grafting copolymerization was investigated. The optimum reaction conditions were determined as follows: c (styrene) = 20.00 mmol, c (H₂O₂) = 5.00 mmol, c (FeCl₂) = 0.10 mmol, T = 30°C and t = 48 h. The optimum yield (Y), total conversion (TC), grafting efficiency (GE), and degree grafted (DG) values were 96.6, 96.3, 59.5, and 53.7%, respectively. The copolymer of lignin grafted PS was separated and characterized by elemental analysis, differential scanning calorimetry, Fourier transform infrared, thermogravimetry analysis, field emission‐scanning electron microscopy, gel permeation chromatography, and nuclear magnetic resonance. It was demonstrated that the solubility what the copolymer exhibited turned out to be the very reverse of the original lignin. The surface properties and structure of lignin were completely changed after grafting copolymerization. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41900.     

Effect of interfacial area on heterogeneous free radical grafting of vinyl monomers in supercritical carbon dioxide: Grafting of acrylic acid on poly(vinylidenefluoride) nanoparticles

The role of the polymer interfacial area on free radical grafting of acrylic acid (AA) onto poly(vinylidenefluoride) (PVDF) was studied at 65°C using supercritical carbon dioxide (scCO₂) as a solvent and swelling agent, benzoylperoxide (BPO) as chemical initiator and PVDF nanoparticles as polymer matrix. Under adopted conditions PVDF particles do not melt neither dissolve in the reaction medium and FTIR analyses performed on carefully washed nanoparticles confirmed the achievement of high grafting levels. The mass fraction of grafted AA increased with the grafting time and the BPO concentration while it decreased when the density of the fluid phase was enhanced. Collected results suggest that the grafting level obtained by free radical grafting of vinyl monomers onto solid polymer in scCO₂ can be significantly enhanced by increasing the interfacial area of the matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41541.     

Functionalization in copolymers based on 4VP:DVB for the removal of Cr(VI) ions from aqueous solution

Adsorption capacity for Cr(VI) ions has been evaluated on two ion‐exchange resins. A gel‐type precursor resin was obtained by suspension polymerization of 4‐vinylpyridine and divinylbenzene monomers with 40% crosslinking degree. It was quaternized with different functional groups to give two ion‐exchange resins. The R2 resin contained sulfobetaine groups, and R3 methyl groups. The resins were characterized by Fourier transform infrared and solid‐state ¹³C CP/MAS NMR spectroscopy and by elemental analysis. An adsorption experiment was carried out by a batch equilibrium procedure. Langmuir and Freundlich isotherm models were used to determine the adsorption capacity. R2 and R3 resins exhibited maximum adsorption capacity q_max = 75.8 and 56.2 mg/g, respectively. The resins achieve equilibrium in 60 min. The R3 and R2 resins showed a retention capacity of 95% and 80% for the Cr(VI) ions, respectively. The behaviors of both resins were explained well by a pseudo‐second‐order kinetics model. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45548.     

Synthesis and modification of epoxy-based divinyl ester resin

Syntheses of epoxy-based divinyl ester resin and its modification with toluene diisocyanate (TDI) are presented. The resin was obtained from commercially available epoxy resin Epidian 5 and methacrylic acid during graduated heating. Three different resin solutions were obtained by adding 45, 50, and 55% of styrene; then, each solution was modified with TDI at room temperature. Properties of the resins before and after modification were studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2062–2067, 2001     

基于二氧化碳、水、太阳能的绿色化工精炼

化石资源为人类提供了不可或缺的化学品、材料以及燃料,但也造成了大量二氧化碳排放。生物质是可以生产低碳化工产品的可再生资源,但要占用有限的可耕地资源。提出了直接以二氧化碳、水和太阳能为原料的绿色化工精炼。采用光电板收集太阳能并转化为电能,电能通过膜式水电解池产生氢气,氢气通入新型生物反应器并在自养菌的作用下把二氧化碳还原为聚三羟基丁酸酯(PHB)。此新型生物反应器解决了因气体溶解性低而影响传质速度的关键技术,微生物干重产出达0.18 g·L^-1·h^-1,其中PHB质量分数约50%。PHB不仅是优良的可生物降解塑料,也是可用于生产C₃～C₄有机低分子和芳香烃的平台化合物。在磷酸催化作用下,PHB可转化为与汽油相当热值和元素组成的C₄～C₁₆燃料油。分离PHB后的细菌生物质残渣可水热分解获得生物油和富氮水相产物。此生物油具有比植物生物油更高的热值,而水相产物可作为营养物用于培养微生物。     

Improvement of impact strength and hydrolytic stability of PC/ABS blend using reactive polymer

Polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) blends have been used widely for specific applications such as in automotive interior and exterior parts, and for office automation equipment parts. This study was conducted to investigate the effects of a reactive polymer as a modifier on properties such as the impact strength of PC/ABS blends. A reaction between PC and maleic anhydride group cannot usually be expected because the end hydroxyl group of PC is capped with an end‐capping agent such as t‐butylphenol to improve PC properties such as fluidity, thermal resistance, and impact strength. However, a reactive polymer that has a maleic anhydride group reacts with the end hydroxyl group of PC hydrolyzed with metal salts. Results show that PC/ABS with a reactive polymer exhibits improved impact strength. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44550.     

Graphene oxide functionalized by poly(ionic liquid)s for carbon dioxide capture

Poly(ionic liquid)s have been demonstrated as high efficient CO₂ absorbents. In the current study, a kind of poly(ionic liquid)s, Poly[2‐(methacryloyloxy)‐ethyl] trimethylammonium tetrafluoroborate (P[MATMA][BF₄]) was used to functionalize graphene oxide (GO). The hybrid in which P[MATMA][BF₄] was covalently bonded on GO platelets was prepared by a simple method, that is, traditional radical polymerization. The characterizations based on transmission electron microscopy, scanning electron microscope, Fourier transform infrared spectroscopy, Raman spectroscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy demonstrated the graft of P[MATMA][BF₄] on GO. N₂ adsorption measurements indicated that P[MATMA][BF₄] also greatly increased the specific surface area of GO. Due to the higher specific surface area and the CO₂ affinity of P[MATMA][BF₄], the GO‐P[MATMA][BF₄] hybrid exhibited a much higher CO₂ adsorption capacity compared with GO, GO‐NH₂, and P[MATMA][BF₄]. Their study showed that the combinations of poly(ionic liquid)s and GO could be promising CO₂ absorbents. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44592.