Synthesis of glycidyl amine adducts and their copolymerization with glycidyl methacrylate

Syntheses of new adducts from glycidyl methacrylate and the following amines: aniline, p‐phenylenediamine, 4,4′‐oxydianiline, 4,4′‐diaminodiphenylmethane, 4,4′‐diaminodiphenyl sulfone, 4,4′‐thiodianiline, and 4,4′‐diaminodicyclohexylmethane, are presented. These adducts were copolymerized with glycidyl methacrylate. The curing process was initiated thermally and by UV light. Thermomechanical properties of the obtained compositions were studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2461–2466, 2005     

Synthesis and characterization superabsorbent‐ethanol polyacrylic acid gels

In this article, superabsorbent‐ethanol polyacrylic acid gels were synthesized by free‐radical aqueous polymerization method by using γ rays as initiator and varying the concentration of the Zn²⁺ from 0.1 to 0.3%, which acts as crosslinker. Effect of irradiation dose, monomer concentration, kind, and concentration of the crosslinker on swelling behaviors of polyacrylic acid gels were investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis,characterization, and antifungal activity of nystatin—gum arabic conjugates

Nystatin, a polyene tetraene antibiotic widely used in the treatment of mycoses, was coupled with oxidized polysaccharide gum Arabic, by forming Schiff base structures between amine groups of antibiotics and aldehyde groups of modified carbohydrate. Imine conjugates synthesized in this way were reduced with sodium borohydride to secondary amines. Two imine and two amine conjugates were obtained with different nystatin content. The conjugates were characterized by UV–Vis, FTIR, ¹H NMR spectroscopy, and thermogravimetric analysis. Solubility in water, unlike nystatin, and significant activity against Candida albicans and Aspergillus niger with minimum inhibitory concentrations in range of 3.125–6.25 μg mL^?1 and 6.25–25 μg mL^?1, respectively, indicate that the chemical integrity and the biological function of these compounds were retained. A comparison of stability of the conjugates in the dry form, solution and under different pH values showed that the conjugates exhibited better stability than pure drug. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Baylis-Hillman加成物的合成及生物活性研究

以三甲胺、1,4-重氮二环[2,2,2]辛烷(DABCO)为催化剂,室温合成了19个Baylis-Hillman加成物(BH),生物活性测试发现:在2000g a.i./ha的剂量下,2-((2,4-二氯苯基)(羟基)甲基)丙烯酸甲酯(BH-7)具有较为广谱的除草活性,对阔叶杂草百日草和苘麻的防效达到100％;对禾本科...     

Synthesis in inverse emulsion and properties of water‐soluble associating polymers

An inverse, free‐radical emulsion polymerization technique was designed for the preparation of copolymers of acrylamide and sodium acrylate modified with low amounts (<0.5 mol %) of a series of amphiphilic comonomers, the isooctylphenoxy–poly(oxyethylene)(n) methacrylates (1 ≤ n ≤ 12). The products of the reaction were hydrophobically modified water‐soluble polymers (HMWSPs) of high molecular weight encapsulated within water droplets dispersed in an organic medium. Kinetic studies showed that the full‐conversion samples were rather homogeneous in composition because of the specificity of the process. A mechanistic scheme is proposed that accounts for the incorporation level of the amphiphilic comonomer as a function of its hydrophile–lipophile balance and the nature of the redox initiator (hydrophilic or lipophilic). The rheological properties of the HMWSPs in aqueous solutions were investigated as a function of the comonomer content and the nature of the initiator with steady‐flow experiments. The thickening properties were directly correlated to the conditions of synthesis and were optimal when the initiator and the amphiphilic comonomer were located in two distinct phases. A maximum in viscosity was observed for a hydrophobe content of about 0.3 mol %. An examination of the viscosity as a function of the shear rate and time showed that these solutions had all the characteristics of associating polymers. The complex rheological behavior was the result of the balance between interchain and intrachain hydrophobic liaisons and the kinetics of disorganization and reorganization of the network structure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1418–1430, 2002; DOI 10.1002/app.10337     

Synthesis of a novel series of propargyloxyphenyl maleimides and their characterization as thermal‐resistance resins

Novel thermosetting monomers possessing both maleimide and propargyl groups were first designed and synthesized. The monomers included N‐(2‐propargyloxyphenyl) maleimide (2‐PPM), N‐(3‐propargyloxyphenyl) maleimide (3‐PPM), and N‐(4‐propargyloxyphenyl) maleimide (4‐PPM), and their structures were confirmed with Fourier transform infrared (FTIR) spectroscopy, ¹H‐NMR, and elemental analysis. The cure behaviors of these monomers were characterized with differential scanning calorimetry and FTIR spectroscopy, and the results indicated that the monomers had a broader processing window than normal bismaleimide (BMI) resins. The thermal properties of the cured monomers were characterized with thermogravimetric analysis and dynamic mechanical analysis. The 5% mass loss temperatures of the cured monomers were high (ca. 400°C), and the glass‐transition temperatures of cured 2‐PPM, 3‐PPM, and 4‐PPM were 386, 373, and 387°C, respectively, which were much higher than those of typical commercial blended BMI resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

反相悬浮聚合法制备水溶性固体聚丙烯酸

以环己烷为连续相,失水山梨醇单油酸酯(Span-80)为分散剂,K2S2O8为引发剂,采用反相悬浮聚合法合成了水溶性良好的固体聚丙烯酸(PAA),详细探讨了搅拌速度、分散剂用量、单体浓度、反应温度及反应时间等对聚合产物颗粒特性的影响。结果表明,较优的工艺条件是:搅拌速度500r/min、分散剂质量分数4%~8%(相对于单体质量)、单体质量分数50%、反应温度70℃、反应时间3.0h。     

Synthesis in inverse emulsion and associating behavior of hydrophobically modified polyacrylamides

An inverse free‐radical emulsion polymerization technique was used to prepare copolymers of acrylamide and two different hydrophobic comonomers: N,N‐dihexylacrylamide (diC6) or N,N‐diphenylacrylamide (diPh). The products of the reaction were high molecular weight hydrophobically modified water‐soluble polymers (HMWSPs) encapsulated within water droplets dispersed in an organic medium. A comparison of the copolymer compositions prepared under different experimental conditions showed that the level of incorporation of diPh in the final copolymer depended strongly on its localization in the emulsion (aqueous or oil phase) and on the nature of the redox initiator pair (water‐soluble or oil‐soluble). The rheological properties of the HMWSPs in aqueous solution were investigated as a function of the comonomer content and the nature of the initiator, using steady‐flow experiments. The thickening properties were found to be directly correlated to the conditions of synthesis and were optimal when the initiator and the hydrophobic comonomer were located in two distinct phases. An examination of the viscosity as a function of shear rate showed that these solutions exhibit typical characteristics of hydrophobically associative polymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 916–924, 2004     

Graft copolymerization of acrylic acid on methylcellulose by ceric ion/p‐xylene redox pair

The graft copolymerization of acrylic acid onto methylcellulose by ceric ion/p‐xylene redox pair was investigated in aqueous media under homogeneous conditions. The graft yield dependency on p‐xylene concentration in the range 1.8–45.0 × 10^?5M showed a minimum and an enhanced yield when the methylcellulose interacted with ceric ion and p‐xylene for an initial period of 10 min (preoxidation time) prior to addition of monomer to the reaction medium. This was attributed to the presence of two kinetically controlled reactions initiated by p‐xylyl radical and diradical species. At prolonged preoxidation times of 30 and 60 min, the graft yield dependency on p‐xylene concentration was normal and suggested the presence of only one initiating species. The effect of ceric ion on the graft reaction in the concentration range of 8.33–83.3 × 10^?3M was optimal at 131% graft yield for ceric ion concentration of 16.7 × 10^?3M and was reduced significantly by as much as 75% at the highest concentration of the latter. The temperature dependency of graft yield was negative in the region 30–50°C. At 50°C the initial rate of graft was only 37% of the value at 30°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 500–504, 2002; DOI 10.1002/app.10200     

Polymerization of cyclic monomers. VII. Synthesis and radical polymerization of 1,3‐bis[(1‐alkoxycarbonyl‐2‐vinylcyclopropane‐1‐yl)carboxy]benzenes

1,3‐Bis[(1‐alkoxycarbonyl‐2‐vinylcyclopropane‐1‐yl)carboxy]benzenes 1 [RO: CH₃O (a), C₂H₅O (b)] were synthesized by the esterification of the corresponding 1‐alkoxycarbonyl‐2‐vinylcyclopropane‐1‐carboxylic acids with resorcinol. The structure of the new vinylcyclopropanes was confirmed by elemental analysis and infrared (IR), ¹H nuclear magnetic resonance (¹H‐NMR), and ¹³C nuclear magnetic resonance (¹³C‐NMR) spectroscopy. The radical polymerization of difunctional 2‐vinyl‐cyclopropanes in bulk with 2,2′‐azoisobutyronitrile (AIBN) results in hard, transparent, crosslinked polymers. During the bulk polymerization of the crystalline bis[(1‐methoxycarbonyl‐2‐vinylcyclopropane‐1‐yl)carboxy]benzene 1a, an expansion in volume of about 1% took place. The radical solution polymerization of 1a resulted in a soluble polymer with pendant 2‐vinylcyclopropane groups. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1775–1782, 1999     

Synthesis and characterization of emulsion copolymer of N‐cyclohexylmaleimide and methyl methacrylate

Copolymers of N‐cyclohexylmaleimide (ChMI) and methyl methacrylate (MMA) were synthesized by the emulsion semibatch copolymerization method. The effects of the monomer mixture composition on the average molecular weight (M_n and M_w ), glass transition temperature (T_g), degradation temperature, mechanical properties, and rheological behavior of the copolymers were investigated. The results show that M_n and M_w have maximum values when the ChMI feed content was about 20% (by wt). The degradation temperature and T_g of the copolymers increase with increasing ChMI moieties in the copolymer. The mechanical properties (tensile strength and impact strength) decrease with an increasing ChMI feed content. All copolymers in the melt show pseudoplastic behavior. The flow index n increases with an increasing ChMI feed content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1070–1075, 2002; DOI 10.1002/app.10394     

Preparation and characterization of Calendula officinalis-loaded PCL/gum arabic nanocomposite scaffolds for wound healing applications

Medicinal plants such as Calendula officinalis (C. officinalis) are commonly used for skin wounds’ treatment. On the other hand, gum arabic (GA) has a lot of potential for use in wound healing because of its unique physio-chemical properties. Wound healing activity of gum arabic (GA) and Calendula officinalis (C. officinalis) along with good mechanical properties of poly (ε-caprolactone) (PCL) can produce a suitable nanofibrous scaffold for skin tissue engineering as well as wound dressing application. In this study, PCL/C. officinalis/GA nanofibrous scaffolds with diameter distribution in the range of 85–290 nm were prepared via electrospinning. Characteristics of the nanofibrous scaffolds, i.e., morphology, scaffold compounds, porosity, mechanical and antibacterial properties, hydrophilicity and degradability in phosphate buffer saline (PBS) were investigated. Cell viability and proliferation of scaffolds were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. Results indicated that hydrophilicity of the PCL/C. officinalis/GA scaffolds was higher than the PCL scaffold. The tensile strength and elongation of the PCL/C. officinalis/GA scaffolds were in the range of 2.13–4.41 MPa and 26.37–74.37%, respectively, which are very suitable for skin tissue engineering. The porosity of the scaffolds was higher than 60% and was appropriate for the proliferation of fibroblast cells. The nanocomposite scaffold also showed suitable degradability and antimicrobial activity. Moreover, cell culture indicated that GA and C. officinalis promoted cell attachment and proliferation. It can be concluded that the nanofibrous calendula-loaded PCL/GA scaffolds are well suited for regenerating skin.

     

聚丙烯酸/高岭土复合高吸水树脂的制备及结构性能研究

以丙烯酸和高岭土为原料,采用水溶液聚合法制备了聚丙烯酸/高岭土复合高吸水树脂,对其结构性能进行了研究。结果表明:当丙烯酸质量分数为20%,高岭土质量分数为10%,过硫酸钾质量分数为0.13%,N,N'-亚甲基双丙烯酰胺质量分数为0.2%,反应温度为80℃,反应时间为3 h时,所制的聚丙烯酸/高岭土复合高吸水树脂表面形貌良好,高岭土分散均匀,吸水倍率为132 g/g,保水率为93.9%,凝胶形变量为2.3 mm;聚丙烯酸高吸水树脂的吸水倍率为121 g/g,保水率为82.5%,凝胶形变量为7.1 mm;高岭土的加入不仅提高了聚丙烯酸树脂的吸水倍率、吸水速率与保水率,且显著提高了聚丙烯酸树脂的凝胶强度。     

Synthesis and characterization of PNIPAM/PS core/shell particles

Crosslinked, monodisperse PNIPAM particles were synthesized by precipitation polymerization. The particle size was measured by dynamic light scattering (DLS), capillary hydrodynamic fractionation (CHDF), and transmission electron microscopy (TEM). Two different polymerization methods were used to prepare PNIPAM/PS core/shell particles, both above and below the volume phase transition temperature (VPPT) using either a semibatch or seeded semibatch polymerization process. In both processes, uniform “raspberry” structures were obtained in which polystyrene formed small domains on the surface of the PNIPAM particles. The resulting core and shell structure was confirmed by temperature‐dependent particle size and density gradient experiments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Poly(acrylic acid)/gum arabic/ZnO semi-IPN hydrogels: synthesis,characterization and their optimizations by response surface methodology

Iranian Polymer Journal - Synthesis of novel semi-interpenetrating poly(acrylic acid) (PAA)/gum arabic (AG)/ZnO hydrogels by in situ free radical polymerization was optimized using response surface...     

聚丙烯酸钠的合成及应用

综述了不同相对分子质量的聚丙烯酸钠及聚丙烯酸钠高吸水性树脂的合成方法。分别介绍了它们的应用领域。不同相对分子质量聚丙烯酸钠的合成主要采用水溶液法。根据其聚合程度的不同，分别用于石油化工、日用化工、污水处理及陶瓷制作等领域。聚丙烯酸钠高吸水性树脂的合成主要有水溶液聚合法、反应悬浮聚合法、反向乳液聚合法，微波及辐射聚合法。介绍了它在日用化工、农业、医药及建筑行业中的应用。并结合目前国内的发展状况，对今后我国聚丙烯酸钠的研制和发展作出展望。     

表面接枝高密度磺酸基聚苯乙烯的制备及表征

以无水溴化铝为催化剂,对氯苯甲醛为醛基化试剂,通过傅克反应在聚苯乙烯微球表面接枝醛基;基于醛基的可氧化性,利用还原剂硝酸铵铈将树脂微球表面的醛基自由基化,引发对苯乙烯磺酸钠在树脂微球表面聚合,并对其进行表征。结果表明,聚苯乙烯微球磺酸化改性成功,优化的磺化工艺条件为:醛基含量1.5 mmol/g的聚苯乙烯微球用量0.3 g,对苯乙烯磺酸钠质量浓度40 g/L,硝酸铵铈质量浓度40 g/L,反应温度70℃,在此条件下制备的树脂表面磺酸基含量为58 mmol/g。     

Synthesis and characterization of poly(acrylonitrile)/montmorillonite nanocomposites from surface‐initiated redox polymerization

We have developed a facile method to prepare polyacrylonitrile/montmorillonite (PAN/MMT) nanocomposites using the surface‐initiated redox polymerization of acrylonitrile (AN) in the aqueous phase. The MMT silicate surfaces were first treated with diethanolamine, and the modified MMT (DEA‐MMT) was subsequently used together with the Ce(IV) salt to serve as a redox system. The PAN chains growing on a surface‐tethered DEA expand the interlayer space, and thus lead to intercalated/exfoliated nanocomposites. The nano‐morphology of the prepared nanocomposites depends on the AN/OH molar ratio in feed. An exfoliated PAN/MMT nanocomposite was obtained when the feeding AN/OH molar ratio = 300 was used. The molecular weight of PAN in the nanocomposites prepared by the present method is also dependent on the AN/OH molar ratio in feed and can be up to ca. 160,000 g/mol. The differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) analyses show that the increasing fraction of exfoliated silicate structures should enhance the contact interface between the silicate and polymer, resulting in the higher glass transition temperature and thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and photovoltaic device studies of azo‐linked low‐bandgap polymers

We report the synthesis of a series of new polymers containing azo linkage as a part of the main chain. The monomer 1,2‐bis(7‐bromo‐9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazene was synthesized using a precursor approach which avoids non‐selective bromination and was copolymerized with various donor or acceptor units. The homopolymer poly[1,2‐bis(9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazene] ( P1 ) as well as the copolymers poly[1‐(9,9‐dioctyl‐9H ‐fluoren‐2‐yl)‐2‐(9,9,9′,9′‐tetraoctyl‐9H ,9′H ‐[2,2′‐bifluoren]‐7‐yl)diazene] ( P2 ), poly[1‐(9,9‐dioctyl‐7‐(4‐octylthiophen‐2‐yl)‐9H ‐fluoren‐2‐yl)‐2‐(9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazene] ( P3 ) and poly[4‐(7‐((9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazenyl)‐9,9‐dioctyl‐9H ‐fluoren‐2‐yl)benzo[c ][1,2,5]thiadiazole] ( P4 ) were synthesized by Suzuki polymerization. The copolymers poly[1‐(7‐(4,4‐dioctyl‐4H ‐cyclopenta[1,2‐b :5,4‐b ′]dithiophen‐2‐yl)‐9,9‐dioctyl‐9H ‐fluoren‐2‐yl)‐2‐(9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazene] ( P5 ) and poly[4‐(5‐(7‐((9,9‐dioctyl‐9H ‐fluoren‐2‐yl)diazenyl)‐9,9‐dioctyl‐9H ‐fluoren‐2‐yl)‐4‐octylthiophen‐2‐yl)‐7‐(4‐octylthiophen‐2‐yl)benzo[c ][1,2,5]thiadiazole] ( P6 ) were synthesized by direct arylation polymerization reaction. Polymers synthesized using the direct arylation method show good molecular weight, with absorption maxima in the range 500 to 532 nm. P5 and P6 possess low optical bandgaps of 1.81 and 1.86 eV, respectively. A power conversion efficiency of 0.53% with open circuit voltage of 0.53 V, short circuit current density of 3.1 mA cm^?2 and fill factor of 29% has been achieved with C71‐PCBM as acceptor in bulk heterojunction solar cells fabricated with P5 as donor. © 2016 Society of Chemical Industry     

Synthesis,characterization, flocculation,and rheological characteristics of hydrolyzed and unhydrolyzed polyacrylamide‐grafted poly(vinyl alcohol)

Graft copolymers of poly(vinyl alcohol) and polyacrylamide (PVA‐g‐PAM) were synthesized using a ceric ion–induced solution polymerization technique at 28°C. Three grades of graft copolymers were synthesized with varying acrylamide concentrations. Three grades of hydrolyzed products of PVA‐g‐PAM were synthesized with varying concentrations of sodium hydroxide solution. Hydrolyzed and unhydrolyzed PVA‐g‐PAM were characterized by viscometry, X‐ray diffractometry, infrared spectroscopy, and thermal analysis. Rheological investigation was also carried out on the aqueous solutions of various samples. The flocculation characteristics of various materials were investigated by the use of jar and settling tests in 0.25 and 5 wt %, respectively, using kaolin and iron ore suspensions. Among the series of graft copolymers, the one with fewest but longest PAM chains showed superior performance. The flocculation characteristics of the best‐performing graft copolymer were compared with those of various commercially available flocculants in the two suspensions under investigation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2109–2122, 2006