以水为溶剂马来酸酐-丙烯酸共聚物的合成及阻垢性能研究

以水做溶剂,采用自制的催化剂合成了马来酸酐（MA）－丙烯酸（AA）共聚物（MA／AA）,考察了合成条件与共聚物性质的关系。探讨了共聚物对CaCO3、Ca3（PO4）和CaSO4的阻垢率与引发剂用量、滴加时间以及单体配比之间的关系。实验结果表明,合砀共聚物对碳酸钙、硫酸钙、磷酸钙具有良好的阻垢性能。在药剂用量为12mg/L时,对碳酸钙的阻垢率达98％以上;对硫酸钙、磷酸钙也分别为58％和69％。该共聚物可用作工业循环冷却水的阻垢剂。     

Synthesis and application of a new vinyl copolymer superplasticizer

A new vinyl graft copolymer superplasticizer was synthesized by copolymerization of polyethylene glycol acrylate (PEGAA), polyethylene glycol biester of maleic acid and citric acid (PEGMC), acrylic acid (AA), sodium allylsulphonate (SAS), and methyl acrylate (MA). The effects of the vinyl monomers' molar ratio, initiator, reaction temperature, and reaction time on its application properties were investigated. The results show that the new vinyl graft copolymer superplasticizer has excellent application properties when the molar ratio of PEGAA, PEGMC, AA, SAS, and MA is 0.5 : 0.10 : 0.20 : 0.05 : 0.03 and the initiator ammonium persulfate [(NH₄)₂S₂O₈, APS] is 0.8 wt % at 80°C for 3 h. The vinyl monomers' conversion is 98.7%. The applied results show that the water‐reducing ratio and retardation solidification time of the superplasticizer reach 33.5% and 4 h, respectively. The applied concrete has excellent mechanical properties. Its molecular structure was characterized by nuclear magnetic resonance, Fourier transform infrared spectra, and gel permeation chromatography. It is characteristic of the new vinyl graft copolymer superplasticizer that citric acid (CA) and MA are introduced into the copolymer molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

一种新型聚降冰片烯类无规共聚物的合成与表征

降冰片烯衍生物的开环易位聚合具有反应条件温和、反应速率快及尺寸可控等优点,且因其独特的结构使得聚合物主链具有良好的热稳定性及耐酸碱性能。本文通过开环易位聚合法制备了降冰片烯基苯磺酰氯(NBSC)与5-降冰片烯-2,3-二羧酸二甲酯(DCNM)的新型二元无规共聚物。通过FT-IR、NMR表征了单体和共聚物的化学结构,并通过设计对比实验探究了最佳反应条件。GPC数据显示,当两单体配比1:1,催化剂用量为单体总物质的量1/450,反应时间30 min,反应温度40℃时,共聚物的相对分子质量最大,分子量分布较窄,产率最高,此条件为最佳反应条件。DSC表明,DCNM单体均聚物的T_g为60℃,与NBSC共聚后,T_g升高至80℃左右。TGA数据显示共聚物质量分解5%时对应的温度为145℃,最大分解速率时的温度为245℃,证明该聚合物具有良好的热稳定性。综合考虑其各项性能,这种新型的聚合物有望用于燃料电池质子交换膜领域的研究。     

片状碳酸钙粒子的制备及表征

在乙二胺四乙酸钠((EDTA2Na)和三氯化铝(AlCl3)为添加剂,通过鼓泡法,制得片状CaCO3粒子。利用场发射扫描电镜(FESEM)、X射线衍射(XRD)和热重(TGA)对所得碳酸钙产品的结构和性质进行表征。     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

Synthesis of silicon ester dispersants and its application in CaCO3/polyethylene composites

Silicon ester dispersants were prepared using transesterification between ethyl petroleum silicate and the alkyl alcohols by different molecular masses. The dispersants were used to modify calcium carbonate (CaCO₃), and their effect on the mechanical properties of CaCO₃/polyethylene (PE) composites was investigated. The transesterification was confirmed by gas chromatography (GC). The optimal conditions for the preparation of silicon ester dispersants were 110°C for 3 h with 2% catalyst by weight and fixed molar ratio of isooctyl alcohol to ethyl petroleum silicate of 3 : 1. Fourier transmission infrared spectroscopy (FTIR) results indicated that the dispersants were coating to the CaCO₃ particles. Dispersant with octadecanol as its solvable chain enabled the best modification effect. CaCO₃/PE composites modified by dispersants demonstrated improved mechanical properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and characterization of a pentaerythritol-based amphiphilic star block copolymer and its application in controlled drug release

A star-like amphiphilic copolymer was synthesized via RAFT polymerization by using a pentaerythritol-based compound (PTDBA) as a chain transfer agent with Styrene and DMAEMA as monomers. The polymer structure was characterized by FTIR, ¹H NMR, ¹³C NMR and SEC/MALLS. After the retardation period, the molecular weight of PS-CTA and PMMA-CTA increased linearly with monomer conversion. The amphiphilic copolymer self-assembled into spherical micelles when water was added into its DMF solution. The particle size and polydispersity index (PDI) of the micelles in deionized water were about 406 nm and 0.113, respectively. In a pH 10 buffer solution and low micelle concentration, the micelle size decreased with temperature increase. At higher temperatures and micelle concentrations the size increased, resulting in precipitation among agglomerating micelles. This phenomenon was not observed in deionized water. Furthermore, the copolymer effectively prolonged the release time of chlorambucil (CLB) in deionized water.     

Synthesis of a soluble conjugated copolymer based on dialkyl-substituted dithienothiophene and its application in photovoltaic cells

A soluble conjugated alternating 3,5-didecanyldithieno[3,2-b:2′,3′-d]thiophene-thiophene copolymer was synthesized by palladium(0)-catalyzed Stille coupling reaction. The thermal, absorption, emission, electrochemical, and photovoltaic properties of the polymer were examined. A weight-average molecular weight around 6.2 × 10⁴ and a polydispersity index of 1.8 was estimated for the polymer using gel permeation chromatography. The polymer exhibits good thermal stability with decomposition temperature of 340 °C and glass-transition temperature of 136 °C. The polymer shows strong absorption peaked at 505 nm in diluted solution and 518 nm in thin film with an optical band gap 2.0 eV. The polymer exhibits intense emission located at 550 nm in solution and 603 nm in film. The HOMO and LUMO energies of the polymer were estimated to be −5.4 and −3.4 eV, respectively, by cyclic voltammetry. Polymer solar cells were fabricated based on the blend of the polymer and methanofullerene [6,6]-phenyl C61-butyric acid methyl ester (PCBM). The power conversion efficiency of 0.7% was achieved under AM 1.5, 100 mW/cm² using polymer:PCBM (1:4, w/w) as active layer.     

重钙的处理及其在塑料中的应用

研究了铝酸酯等复合处理剂对重质碳酸钙的活化方法，对制得的活性重质碳酸钙的活化度及石蜡油／碳酸钙混合物的粘度行为进行了表征，拉伸实验结果表明，经过活化处理的重度碳酸钙对LDPE／重质碳酸钙复合材料断裂伸长率的改善特别有效。     

端羟基聚异戊二烯及其共聚物的合成与表征

以仲丁基锂为引发剂,引发异戊二烯本体负离子聚合,再用环氧丙烷甲醇终止法合成了端羟基聚异戊二烯;然后利用端羟基聚异戊二烯的活性端羟基,引发丙交酯的开环聚合制备了聚乳酸一聚异戊二烯共聚物,并采用IR、^1H—NMR、TG等测试手段对产品进行了表征。结果表明,通过改变仲丁基锂及环氧丙烷的用量,可合成相对分子质量及羟基含量可控的且1,4-结构质量分数超过87．5％的端羟基聚异戊二烯。     

Synthesis of novel copolymer based on precipitation polymerization and its application in positive-tone photoresist

A series of copolymers Poly (TBA-CA-St-ASM)(PTCSA) were synthesized via precipitation polymerization by using tert-Butyl acrylate (TBA), Styrene (St), p-acetoxy styrene (ASM), and cedryl methacrylate (CA) as co-monomer. Then, Poly (TBA-CA-St-HS)(PTCSH) was prepared in the presence of sodium methoxide in methanol. The fourier transfer infrared (FT-IR) spectra and proton nuclear magnetic resonance (¹H–NMR) spectra indicated that the synthesis was successful. The molecular weight, glass transition temperature (T_g) and thermal decomposition temperature (T(10%)) of the copolymers increased with the addition of CA. Moreover, a positive-tone chemically amplified Krypton Fluoride (KrF) photoresist was prepared, and the photolithography performance of the photoresist was evaluated using a KrF laser exposure system, the result showed that the resolution could reach the level of 0.25 μm.     

Synthesis and self-assembly of amphiphilic maleic anhydride-stearyl methacrylate copolymer

Amphiphilic maleic anhydride-stearyl methacrylate (MA-SMA) random copolymer was synthesized via the free radical copolymerization and its amide was prepared through the MA moieties being reacted with morpholine. Polymers obtained were characterized by GPC and ¹H NMR. The aggregating behaviors of copolymers were investigated by first dissolving them in tetrahydrofuran (THF) and then adding water to induce association of the long alkyl chains and observed over the range of copolymer concentrations from 0.028 to 0.22 wt% and water content from 5.32 to 34.85 wt%. Resultant aggregates show new potential application in the fields of drug delivery systems, microcapsules and so on.     

Synthesis and characterization of a PE-g-LCP copolymer

The possibility of reinforcing polyethylene (PE) by blending it with a liquid crystalline polymer (LCP) rests on the successful improvement of phase compatibility and interfacial adhesion of these two structurally unlike polymers. The approach that is being considered in our laboratories consists of the synthesis of PE–LCP block or graft copolymers and of their use as compatibilizing agents for PE/LCP blends. In this work, the melt polycon-densation of sebacic acid (S), 4,4′-dihydroxybiphenyl (B), and 4-hydroxybenzoic acid (H) has been carried out at temperatures up to 280°C in the presence of an oxidized low molar mass PE sample containing free carboxylic groups (PEox), with the main scope of demonstrating that a PE-g-LCP copolymer may be synthesized by this route. The polycon-densation product has been fractionated by successive extractions with boiling toluene and xylene. The soluble fractions and the residues have been characterized by IR and NMR spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TG, DTG), and scanning electron microscopy (SEM). The extractions and the analyses have been repeated on a PEox/LCP blend prepared by melt mixing PEox and preformed LCP (SBH 112, by Eniricerche). The results show that, whereas for the blend a fairly clean separation of PEox and SBH can be obtained by solvent extraction, this is not so for the polycondensation product. All analytical procedures concordantly show that a PEox-g-SBH copolymer has, in fact, been obtained. In effect, both PEox and SBH chain segments are present, with different relative ratios, in all fractions of the polycondensate. Moreover, a fairly quantitative esterification of the PEox carboxyl groups has been shown by IR analysis to take place in the adopted conditions. Preliminary morphological investigations carried out by SEM have shown that the addition of the synthesized graft copolymer into HDPE/SBH blends leads to an improvement of the interfacial adhesion. © 1996 John Wiley & Sons, Inc.     

Preparation and characterization of nano‐CaCO3 encapsulated by copolymerization of styrene and maleic anhydride

Encapsulated nanometer calcium carbonate (nano‐CaCO₃) was prepared using styrene and maleic anhydride (MAH) copolymer in 2‐propanol or methanol–water mixture in the presence of different initiator systems. The particle morphology and physical properties of the encapsulated nano‐CaCO₃ particles, such as the interaction between the encapsulating polymer and the nano‐CaCO₃, and the thermal stability of encapsulated nano‐CaCO₃ were studied by Fourier‐transform infrared spectroscopy (FTIR), Soxhlet extraction experiments, thermogravimetric analysis banded with FTIR (TGA‐FTIR) and transmission electron microscopy (TEM). The encapsulating ratio and the stable encapsulating ratio of encapsulated nano‐CaCO₃ were characterized. The results showed that a strong interfacial interaction was obtained due to the formation of a chemical bond or ion‐dipole between the C?O group of MAH and Ca²⁺ ion of nano‐CaCO₃. The encapsulating ratio and stable encapsulating ratio of nano‐CaCO₃ initiated by AIBN was higher than that initiated by BPO. Addition of maleic anhydride increased the encapsulating ratio and the stable encapsulating ratio of encapsulated nano‐CaCO₃. For the encapsulated nano‐CaCO₃ prepared in methanol–water, the diameter of the encapsulated nano‐CaCO₃ particle increased from 60–70 nm to about 100 nm and the morphology changed from a cube with a sharp edge to spherical with a rough surface. Copyright © 2006 Society of Chemical Industry     

Synthesis of CaCO3–P(MMA–BA) nanocomposite and its application in water based alkyd emulsion coating

As part of broader effort to synthesize a new class of water-based composite, hybrid emulsion polymerization was carried out with acrylic monomers [methyl methacrylate (MMA), n-butyl acrylate (BA)]. Nanocomposite of P(MMA–BA)/nano CaCO₃ was synthesized by in situ emulsion polymerization. Water-based alkyd coating with various proportions nano CaCO₃, P(MMA–BA) and its nanocomposite was formulated. Extent of polymerization with and without nano CaCO₃ was measured using gravimetric method. Thermal properties of neat polymer, nanocomposite and coating films were evaluated by TGA and DSC, DTA analysis. Uniform dispersion of nano CaCO₃ in polymer matrix was ensured from SEM/TEM images. Incorporation of nanoparticles to hybrid polymer and nanocomposite to alkyd emulsion showed significant enhancement in mechanical and thermal properties. Dual role of nanocomposite in coating; as a partial binder and a filler to improve property profile of neat coating has been reported.     

Synthesis and characterization of a new alternating copolymer containing quaterphenyl and fluorenyl groups

An alternating copolymer was synthesized by Suzuki reaction from 4,4′-dibromo-p-quaterphenyl (PPP oligomer) and 9,9-dioctylfluorene-2,7-diboronic acid in good yield (84%). The copolymer is partially crystalline, readily soluble in organic solvents, presents high fluorescence quantum yield (85.6%) and high thermal stability. The copolymer absorption as well as the emission spectra are red shifted compared to those of monomers. Ultrafast time-resolved fluorescence experiments on the copolymer were carried out and confirmed the results obtained from stationary experiments. The copolymer fluorescence decay is found to be bi-exponential with fluorescence lifetimes of 297 ± 6 ps and 942 ± 5 ps.     

“一步法”合成改性纳米碳酸钙及表征

通过直接沉淀法、微乳液法和水热法合成并改性了纳米CaCO3。3种方法均有表面活性剂的介入,目的在于表面活性剂在控制碳酸钙晶粒生长的同时可使纳米CaCO3表面得到改性。采用X射线衍射(XRD)、红外光谱(FTIR)、透射电镜(TEM)等分析测试方法对产物的物相、形貌及颗粒大小进行表征。结果表明,采用水热法在十二烷基磺酸钠(SDS)和EDTA共同作用下得到粒径为20~50 nm的方解石型纳米CaCO3,通过表面活性剂与纳米CaCO3表面的化学吸附实现表面改性的目的。     

马来酸酐-丙烯酰胺交联共聚物的制备及其重金属吸附性能

以N,N-亚甲基双丙烯酰胺为交联剂,马来酸酐(MA)和丙烯酰胺(AM)为单体,溶液法合成了MA-AM交联共聚物,采用傅里叶变换红外光谱表征了其结构,并以原子吸收光谱法为检测手段,研究了交联共聚物的物料比、吸附时间、体系p H值及温度等对Cu2+,Fe3+,Zn2+,Pb2+,Ni3+吸附性能的影响。结果表明,n(AM)∶n(MA)为1∶4时,交联共聚物的吸附性能最佳,且对Zn2+的吸附量最大。Zn2+的最佳吸附条件为35℃,吸附时间1.5 h,p H值为5时,最大吸附量达到99.4 mg/g。     

Electrochemical synthesis and characterization of a novel thiazole-based copolymer and its application in biosensor

A novel copolymer based on 2-aminothiazole (AT) and 2-amino-4-thiazoleacetic acid (ATA) is electrochemically synthesized and then characterized using UV–visible absorption spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and electrochemical techniques. The results confirmed that the obtained polymer was a copolymer rather than a blend or a composite of the respective homopolymers and could improve the electrochemical response of both positively and negatively charged analytes. Therefore, the copolythiazole film was applied to determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). It is found that the peak separating degrees and peak currents of AA, DA and UA at copolythiazole modified electrode were much better than those at bare GCE. Under the optimum conditions, the linear calibration curves were obtained in the range of 10–2000 μM for AA, 1–150 μM for DA, 1–180 μM for UA. The detection limits of AA, DA and UA were 2, 0.04 and 0.4 μM, respectively (S/N = 3). The practical application of the modified electrode was demonstrated by the determination of UA in urine sample.     

Preparation and characterization of nano‐CaCO3 encapsulated with polyacrylic and its application in PVC toughness

The properties and morphology of nano‐calcium carbonate (nano‐CaCO₃) modified with the titanate coupling agent isopropyl trioleoyl titanate (IPTT) were characterized by Fourier transform infrared, thermogravimetric analyses, surface tension, and transmission electron microscopy. The results showed that the grafting ratio of IPTT on the surface of nano‐CaCO₃ (IPTT‐Ca) increased with IPTT content. IPTT‐Ca/PBA/PMMA (IPTT‐Ca/ACR, PBA/PMMA core‐shell polymer, referred to ACR) latexes were prepared by seeded emulsion polymerization. They were then used to mix with PVC resin. The outer layer (PMMA) enhanced the dispensability of IPTT‐Ca/ACR in the PVC matrix by increasing the interfacial interaction of these composite particles with PVC. The notched impact strengths of the blends were influenced by the weight ratio of IPTT‐Ca to BA/MMA monomers, the weight ratio of BA/MMA. The relationships between the mechanical properties and the core‐shell composite structures were elaborated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010