Modification and Application of Poly(Ethylene Terephethalate) Nonwoven Fiber Using Octadecyl Acrylate and Acrylic Acid as Oil Sorbers

Three series of crosslinked octadecyl acrylate and acrylic acid copolymers were prepared through suspension copolymerization based on acrylic acid content (10, 30, 50%wt. ratio). Divinyl benzene (DVB) was used as a crosslinker with different weight ratios (1, 4 and 10%). Isopropyl alcohol or dioctyl phthalate and methyl benzoate were used as two different reaction solvents in the presence of ABIN as initiator. The prepared crosslinked copolymers were characterized by SEM, TGA and FTIR spectroscopic analyses. The prepared polymers were coated onto poly(ethylene terephethalate) nonwoven fiber (NWPET). The effect of copolymerization feed composition, crosslinker wt% and reaction media or solvent on swelling properties of crosslinked polymers were studied through the oil absorption tests in toluene and 10% of diluted crude oil with toluene. It was noticed that the maximum swelling of crosslinked copolymers was increased from 30 to 100 g/g after grafting of copolymers onto NWPET.     

Synthesis of porous divinylbiphenyl copolymers and their sorptive properties towards phenol and its derivatives

Seven porous divinylbiphenyl polymers having the same nominal crosslinking degree (51.8 wt.%) have been synthesized using suspension polymerization method in the presence of the following inert diluents or their mixtures: toluene, heptane, dodecane, isooctane. The use of various inert diluents was aimed at changing the extent of polymeric network-diluent interactions. The obtained polymers have specific surface area in the range 50-300 m²/g depending on the type and amount of inert diluents used during polymerization. Their sorptive properties have been studied using dilute (0.5 mmol/l) aqueous solutions of phenol and its derivatives (2-chlorophenol, 2,4-dichlorophenol, 2,4,5-trichlorophenol, 2,6-dimethylphenol, 4-hydroxyphenol). It has been found that sorption, at low equilibrium concentration, follows the order: 2,4,5-trichlorophenol > 2,4-dichlorophenol > 2-chlorophenol > 2,6-dimethylphenol > phenol > 4-hydroxyphenol. Full characteristic of the porous structure of polymers has been obtained by nitrogen adsorption at 77K.     

大孔高交联苯乙烯-双烯-A共聚物的合成及孔结构的研究

利用新型交联剂──双甲基丙烯酰氧苯基丙烷(双烯-A)与苯乙烯悬浮共聚合,以甲苯、异戊醇作致孔剂,合成了一系列大孔高交联共聚物。考察了双烯-A用量、甲苯/异戊醇配比、引发剂用量及分散剂用量对共聚物孔结构的影响,通过红外光谱、表现密度、全自动物理吸附仪及扫描电镜对干燥的共聚物小球进行了表征。结果表明,随交联利双烯-A含量的增加,苯乙烯-双烯-A共聚物的表面孔结构明显增大。共聚物的比表面积、孔容及孔径均随致孔剂中不良溶剂异戊醇含量的增加而明显增大。     

Synthesis of crosslinked poly(butyl methacrylate‐co‐pentaerythritol triacrylate) gel by single electron transfer‐living radical polymerization and its oil‐absorbing properties

A novel high oil‐absorbing crosslinked gel was synthesized by copolymerization of butyl methacrylate (BMA) with a small amount of pentaerythritol triacrylate (PETA) crosslinker using single electron transfer‐living radical polymerization (SET–LRP) initiated with carbon tetrachloride (CCl₄) and catalyzed by Cu(0)/hexamethylenetetramine (HMTA) in N, N‐dimethylformamide (DMF). The polymerization followed first‐order kinetics as indicated by linear increase of monomer concentration with reaction time. Effects of reaction temperature, crosslinker, initiator, and catalyst on the oil‐absorbing properties of the crosslinked gel were investigated in detail. The oil absorptions of the crosslinked gel to chloroform, toluene could reach 51.9, 34.5 g/g, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Properties of polyurethane-polystyrene graft copolymer membranes used for separating water-ethanol mixtures

Polyurethane prepolymers (PU) based on hydrophilic poly(ethylene glycol) (PEG), hydroxypropyl acrylic acid (HPA), 2,4-toluene diisocyanate (TDI), and butanediol (BDO) were prepared by one-step polymerization with butanediol as the chain extender. Polyurethane-polystyrene graft copolymers (PU-g-PS) were synthesized by free radical copolymerization of PU with styrene (ST), 2,2′-azobisisobutyronitrile (AIBN) was used as initiator and toluene as solvent. Experimental results showed that the crosslinked membranes of PU-PS graft copolymers could be used for separating ethanol-water mixtures. The highest value of the separation factor (α) of the crosslinked separation membranes can reach 17.3. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize the properties of PU-PS crosslinked membranes.     

Diels-Alder反应可控制备交联等规聚丙烯

交联改性可以提升聚合物材料的机械性能、热稳定性及化学稳定性。 含有蒽基团的高质均分子量等规聚丙烯(iPP)可由配位共聚合反应制得,随后通过双官能的马来酰亚胺试剂与iPP中悬挂蒽基团间的Diels-Alder反应可以成功制备交联的iPP膜材料。 材料的交联度可以通过凝胶重量分析及膜红外分析得出,并由制备过程中交联剂的加入量有效地调控。 通过示差扫描量热仪(DSC)与广角X射线衍射仪(WAXD)表征发现,随交联度增加,交联改性限制了分子链的运动,iPP的结晶度逐渐降低、结晶能力逐渐下降。 对交联材料的动态热机械分析仪(DMA)测试表明,随交联度增加,iPP的损耗模量逐渐降低,材料韧性变差。 交联iPP的T_g逐渐升高,说明材料的耐热性得到提升。 由于交联形成了聚合物链间的交联网络,形成了更多受力点并且限制了聚合物链的自由移动,交联材料的拉伸强度随交联度的升高而增加,而断裂伸长率逐渐下降。     

Synthesis of hollow crosslinked miktoarm polymer using miniemulsion as templates

Hollow crosslinked polymers (HCPs) were synthesized using arm first method via atom transfer radical polymerization. The polymerization process was performed in miniemulsion system, in which the macroinitiator, PEG‐Br, was in the water phase, whereas the vinyl‐monomer, 4‐vinylpyridine (4VP), and the crosslinker, DVB, were in the butanone phase. TEM images and light scattering characterization showed that the resultant polymer contained a hollow space, and the volume of the hollow space could be adjusted by changing the ratio of water to butanone. Also, hollow crosslinked Miktoarm polymers (HCMPs) were synthesized through this method when two different macroinitiators, PEG‐Br and PNIPAM‐Br, were used to coinitiate the polymerization of the vinyl‐monomer, 4VP and DVB. The ¹H NMR spectra showed that the hollow polymers contained both PEG arms and PNIPAM arms. The hollow morphologies of the resultant Miktoarm polymers were the same as the HCPs. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1651–1660, 2009     

大孔交联甲基丙烯酸缩水甘油酯共聚物的合成及其结构性能研究(Ⅰ)

甲基丙烯酸缩水甘油酯（GMA）为单体，三烯丙基氰尿酸酯（TAC）为交联剂，在致孔剂甲苯、正庚烷存在下，用悬浮聚合法制得一系列大孔共聚物（GT）。测定了共聚物的孔结构性能，讨论了不同交联剂及致孔剂用量和配比对共聚物结构的影响，并初步讨论了特大孔共聚物的形成机理。     

2,4,6‐trichlorophenyl acrylate emulsion‐templated porous polymers (PolyHIPEs). Morphology and reactivity studies

A series of monolithic crosslinked polymers with 2,4,6‐trichlorophenyl acrylate as a reactive component was prepared by free radical polymerization of the internal phases of high internal phase emulsions (HIPEs). The volume ratio of water to oil phase (void volume; 60–90%), crosslinker type (divinylbenzene or ethylenglycol dimethacrylate) and quantity (30–50 mol %) and type of porogenic solvent (chlorobenzene, toluene, chloroform, dichloroethane) were altered to study these effects on the structure and reactivity of the monolithic polymers. The polymer supports were characterized by scanning electron microscopy (SEM), FTIR spectroscopy, elemental analysis and mercury intrusion porosimetry. SEM images revealed an open cellular structure with voids between 1 and 12 μm and window sizes between 0.3 and 3 μm. The porogen had an influence on the surface area, being larger with added porogen and the influence being highest with toluene. Adding toluene also influenced the void size, increasing the average diameter from ～2 μm (no porogen) to ～12 μm (added toluene). Monolithic supports were functionalized by reaction of the ester moieties with tris(2‐aminoethyl)amine derivative and by hydrolysis of the ester groups to carboxylic acids. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4043–4053, 2007     

Preparation of a novel polymeric fluorescent nanoparticle

A new type of narrowly dispersed fluorescent crosslinked polystyrene (PS) nanoparticles (20-50 nm) was synthesized via a modified microemulsion copolymerization of styrene, crosslinker divinyl benzene (DVB) and a hydrophilic comonomer amino ethyl methacrylate hydrochloride (AEMH), in the presence of pyrene. Characterized by steady-state fluorescence spectra, these nanoparticles show high luminescent intensity and the embedded pyrene has a negligible desorption from the nanoparticles. The emission intensity I₁ of the pyrene in the crosslinked nanoparticles is 40 times higher than that of pyrene in toluene or styrene solution with the same concentration. The fluorescence emission intensity can be varied by the amount of the monomer, crosslinker and pyrene, but is influenced little by the amount of AEMH in the range of investigation. The surface of the nanoparticles is modified by amino and amidino functional groups introduced by the comonomer and the initiator 2, 2'-azobis(2-amidinopropane) dihydrochloride (V₅₀), which controls the zeta potential on the particle surface.     

Factors affecting the sorption of Eu(III) on modified silica gel</p> </p>

Summary 8-Hydroxyquinoline in benzene, xylene, chloroform and toluene diluents was used to modify silica gel as a solid phase extractant (SPE) for the sorption of Eu(III) in batch extraction techniques. Influences of solid/liquid ratio, pH, metal ion concentration, particle size and temperature were studied. The optimum initial pH is 4.2, while the maximum sorption capacities for the prepared impregnated resins in benzene, xylene, chloroform and toluene diluents are 18.52, 14.98, 14.79 and 5.94 mg ^. g^-1, respectively. The sorption process is found to be affected by both metal ion concentration and particle size of the impregnated resin. Thermodynamic parameters for the sorption of Eu(III) were determined and the reaction is found to be exothermic and spontaneous with enthalpy-14.23 and-23.71 kJ ^. mol^-1 for benzene and xylene as diluents. Release of the element from the loaded solid particles into 0.01M HNO₃ is@85% and@53% from 8-HQ/benzene/silica gel and 8-HQ/xylene/silica gel.</p> </p>     

Emulsion procedures for thermally reversible covalent crosslinking of polymers

Quaternization and dequaternization of tertiary amine compounds were employed to obtain thermally reversible ionene networks from aqueous colloidal polymer dispersions prepared via emulsion polymerization. Chlorine‐functionalized polymers prepared via the emulsion copolymerization of styrene (St), butylacrylate (BA), or both with chloromethylstyrene, and amino‐functionalized polymers prepared via the emulsion copolymerization of St, BA, or both with 2‐(dimethylamino)ethylacrylate or 4‐vinylpyridine, were reacted without polymer separation, with a ditertiaryamine crosslinker and a dihalide crosslinker, respectively, to obtain crosslinked polymers. Crosslinked polymers were also obtained via the reaction of a chlorine‐functionalized polymer dispersion with an amino‐functionalized polymer dispersion or via the drying of the polymer blend prepared from the two kinds of dispersions. Reactive solubility experiments, flowability investigations (by thermocompression at ca. 215 °C), IR, and ¹H NMR analyses of the obtained crosslinked polymers indicated that the generated ionene bridges dequaternized on heating and requaternized on cooling. In comparison with solution crosslinking, no organic solvent was employed, and simple procedures were required for the preparation of the thermally reversible covalent crosslinked polymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4373–4384, 2000     

介孔聚离子液体的可控合成及在常压CO2环加成反应中应用

采用刚性的离子液体聚合单体双-（3-乙烯基-1-咪唑）亚甲基双溴盐（[C₁DVIM]Br）,以聚乙二醇（PEG）为溶剂,能够简单快捷制备出高比表面积的介孔聚离子液体.通过调节PEG的分子量大小,即可有效控制所得聚离子液体的孔结构.介孔聚离子液体由于具有典型的聚阳离子骨架、较高的比表面积以及丰富的卤素位,作为非金属多相催化剂在常压下氧化苯乙烯为底物的CO₂环加成反应中表现出优异的催化活性和良好的回收稳定性,循环使用5次后催化性能基本保持不变.此外,该催化材料还表现出良好的底物兼容性,可以有效转化很难反应的脂肪类环氧化合物.     

Synthesis and properties of conjugated fluoroalkyl ether-substituted polythiophenes prepared in organic solvent and supercritical carbon dioxide

A number of new fluoroalkyl ether-containing polythiophenes are synthesized via oxidative polymerization in supercritical CO₂ (scCO₂) and chloroform. In both cases, high-molecular-mass polymers with high yields are prepared. The properties of the polymers synthesized in scCO₂, such as molecular mass, polydispersity, conjugation, and UV absorption, are similar to the properties of the polymers obtained in chloroform. All poly(fluoroalkyl ether thiophenes) show solubility in DMF, toluene, THF, chloroform, and acetone. The glass-transition temperatures of the polymers are in the range 58–82°C, and the temperatures corresponding to 10% loss in their weight are in the ranges 248–294 and 260–303°C for poly(fluoroalkyl ether thiophenes) synthesized in scCO₂ and chloroform, respectively. All polymers fluoresce in the blue region with emission maxima at 506 to 526 nm. Because of the unique combination of fluoroalkyl and carbonyl groups, poly(fluoroalkyl ether thiophenes) feature good solubility in scCO₂, which is a promising alternative solvent for the oxidative polymerization of fluoroalkyl ether thiophenes.     

聚二乙烯苯的取代反应研究

以悬浮聚合法制得一系列高交联聚二乙烯苯树脂，通过改变反应试剂、催化剂、反应溶剂考察了聚二乙烯苯树脂进行亲电取代反应的规律．结果表明，聚二乙烯苯树脂可发生亲电取代反应，反应程度较低．聚（对－二乙烯苯）的反应程度高于聚（间－二乙烯苯）．     

交联剂分子量对高吸水性树脂性能的影响

通过丙烯酰氯对聚乙二醇的封端反应合成了一系列分子量不同、结构类似的交联剂———聚乙二醇二丙烯酸酯 (PEGDA) ,并用于聚丙烯酸高吸水性树脂的制备 .运用FTIR对PEGDA进行了分析 .吸水性能实验结果表明 ,交联剂的分子量越大 ,则高吸水性树脂的吸水倍率越高 ,吸水速率越大 ,而相对吸水速率降低 .同时 ,PEGDA与常用的交联剂N ,N′ 亚甲基双丙烯酰胺 (MBA)相比 ,前者制备的高吸水性树脂的吸水倍率远高于后者 ;线型可溶性聚合物及残留单体的含量 ,前者也低于后者     

Influence of diluent composition on the porous structure of methacrylate copolymers

The porous structure of copolymers obtained by suspension polymerization has been investigated. Three different copolymers were synthesized—styrene‐divinylbenzene, ethylene glycol dimethacrylate‐divinylbenzene, and 1,4‐phenylene dimethacrylate‐divinylbenzene. All the copolymers were porous. As a pore‐forming diluent, the mixture of toluene (good solvent) and n‐dodecane (nonsolvent) was used. The influence of the composition of two‐component diluent on the porous structure of the copolymers has been examined. Surface areas, pore volumes, pore size distributions, skeletal and apparent densities, and swellability coefficients were determined for the copolymers obtained in the presence of 0, 15, 50, 85, and 100% (v/v) toluene in the mixture with n‐dodecane. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3079–3085, 2002     

Preparation of oligoamide‐ended poly(ethylene glycol) and hydrogen‐bonding‐assisted formation of aggregates and nanoscale fibers

An oligoamide‐ended poly(ethylene glycol) (PEG) with a PEG weight‐average molecular weight of 5000 (PEG‐5000‐oligoamide), with 3,5‐bis‐[2‐(5‐acetylamino‐2‐isobutoxy‐benzoylamino)‐acetylamino]‐benzoyl as the oligoamide, was synthesized. PEG‐5000‐oligoamide aggregated in chloroform or toluene via hydrogen‐bonding interactions among the oligoamide strands as a core and PEG, which was soluble in the solvents, as a shell. When a chloroform solution of PEG‐5000‐oligoamide at a concentration of approximately 0.06 g/L was cast onto a silicon wafer or a mica plate, rapid solvent evaporation induced its self reassembly as nanofibers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1119–1128, 2005     

Inverse Suspension Polymerization of Partially Neutralized and Lightly Cross-Linked Acrylic Acid: Effect of Reaction Parameters

An inverse suspension polymerization was carried out in laboratory in one Liter Buchi glass reactor to produce superabsorbent polymers (SAPs) based on acrylic monomers for hygiene applications. Strongly water absorbing polymers, based on acrylic acid, sodium acrylate were prepared by copolymerization using potassium per sulfate as initiator and N-N′ methylene-bisacrylamide (MBA) as crosslinking agent. The effect of varying monomer, crosslinker, initiator, dispersant concentration, time of reaction and degree of neutralization, on absorption capacities was investigated. In the present studies, the continuous hydrocarbon phase was taken as 50:50 mixture of n-heptane and cyclohexane (aliphatic-alicyclic) because the availability of crosslinker in the aqueous phase is controlled by the partition coefficient of the crosslinker between the aqueous phase and the continuous hydrocarbon phase. The SAPs were evaluated for their free absorption capacities in distilled water, saline (0.9% NaCl), and also absorption under load (AUL). The experimental results show that these SAPs have good absorbency both in water and NaCl solutions. It was observed that SAP synthesized from acrylic acid with about 70% degree of neutralization, containing 1% cross-linker, and 0.5–1.0% initiator concentration with 10% dispersant exhibited absorption capacities in water, saline and AUL as 220 g/g, 70 g/g and 27 g/g respectively.     

Effect of Crosslinking Agent on Neem (Azadirachta Indica A. Juss.) Seed Oil (NSO) Encapsulated Microcapsules of κ -Carrageenan and Chitosan Polyelectrolyte Complex

Microencapsulation of neem (Azadirachta Indica A. Juss.) seed oil (NSO) was carried out by polyelectrolyte complexation of κ -carrageenan and chitosan. The microcapsules were crosslinked by using three different crosslinking agents - glutaraldehyde, genipin and tannic acid. The lowest and highest water uptake capacities were exhibited by glutaraldehyde and tannic acid crosslinked matrices, respectively. The release behavior of NSO from encapsulated crosslinked microcapsules followed the order: tannic acid > genipin > glutaraldehyde. Polyelectrolyte complex formation and its interaction with crosslinker was studied. Crosslinking improved thermal stability without affecting crystallinity. Roughness appeared on microcapsule's surface indicated interaction between microcapsules and crosslinker.