合成2-甲基烯丙基二乙酸酯的新工艺

以甲基丙烯醛和无水醋酐为原料及强酸性阳离子交换树脂为催化剂合成了2-甲基烯丙基二乙酸酯,考察了催化剂用量、物料配比、反应温度及反应时间对反应的影响。确定了适宜的反应工艺条件:n(醋酐)/n(甲基丙烯醛)为1.2;强酸性阳离子交换树脂用量以甲基丙烯醛的用量(mol)为基准,2.0 g/mol;反应时间5 h,反应温度-10℃。在此条件下,甲基丙烯醛转化率为95.5%,2-甲基烯丙基二乙酸酯选择性和收率分别为95.7%和91.4%。并对产物进行了红外光谱表征,产物的红外谱图和标准谱图基本吻合。

淀粉乙酸酯的烯丙基醚化反应研究

研究了取代度为0.6～1.6的乙酰淀粉溶解在DMF溶剂中,与氯丙烯发生亲核取代醚化反应,均相合成烯丙基淀粉乙酸酯的方法.考察了碱试剂、反应物配比、催化剂、反应温度及反应时间等因素对烯丙基淀粉乙酸酯合成的影响.实验结果表明,叔丁醇钠是比较适宜的碱试剂;当氯丙烯的物质的量是乙酰化淀粉残余羟基值的1.2倍,反应温度为60℃,反应时间为6 h,催化剂为Nal时,乙酰淀粉的烯丙基醚化度可达0.05～1.20.IR和化学分析数据证实了上述实验结果.

丙烯酸-2,4,6-三硝基苯乙酯的合成及热分解

以TNT、甲醛为原料,在弱碱性条件下反应合成得到2,4,6-三硝基苯乙醇(PicCH2CH2OH);PicCH2CH2OH在浓硫酸催化下和丙烯酸在甲苯中回流反应24h,合成得到丙烯酸-2,4,6-三硝基苯乙酯,产率为62%。采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1HNMR)、红外光谱(FTIR)、质谱(MS)以及元素分析等对产物结构进行了表征。利用热重分析(TG)对产物热稳定性进行了研究,采用Kissinger方法和Ozawa方法计算其热分解活化能Ea分别为99.78,102.96kJ·mol-1。

Preparation of Hollow Silica Microspheres via Poly（N-isopropylacrylamide）

Core-shell structured SiO2/poly（N-isopropylacrylamide） （SiO2/PNIPAM） microspheres were successfully fabricated through hydrolysis and condensation reaction of tertraethyl orthosilicate （TEOS） on the surface of PNIPAM template at 50 ~C. The PNIPAM template can be easily removed by water at room temperature so that SiO2 hollow microspheres were finally obtained. The transmission electron microscope and scanning electron microscope observations indicated that SiO2 hollow microspheres with an average diameter of 150 nm can be formed only if there are enough concentration of PNIPAM and TEOS, and the hy- drolysis time of TEOS. FTIR analysis showed that part of PNIPAM remained on the wall of SiO2 because of the strong interaction between PNIPAM and silica. This work provides a clean and efficient way to prepare hollow microspheres.

Study on Synthesis and Chloramphenicol Release of Poly（2-hydroxyethylmethacrylate-co-acrylamide） Hydrogels

In this article, poly（2-hydroxyethylmethacrylate-co-acrylamide） hydrogels were synthesized by bulk free-radical copolymerization of 2-hydroxyethylmethacrylate （HEMA） and acrylamide （AAm） for soft contact lens（SCL）-based ophthalmic drug delivery system. The copolymer was characterized with FT-IR and SEM, the swelling property of the hydrogels were studied by gravimetrical method, and chloramphenicol was used as a model drug to investigate drug release profile of the hydrogels. The results showed that poly（2-hydroxyethylmethacrylateco-acrylamide） hydrogels were transparent and useful SCL biomaterial, the water content increased as AAm content increase and pH decrease, and in the same way, hydrogel composition affected chloramphenicol release process too. Migration rate of chloramphenicol increased as the AAm content in the hydrogels increased in the first stage of diffusion process, whereas there was no significant difference thereafter.

Porous alumina ceramic via gelcasting based on2-hydroxyethyl methacrylate dissolved in tert-butyl alcohol

To obtain porous alumina ceramic with high strength,a novel gelcasting system based on 2-hydroxyethyl methacrylate(HEMA)dissolved in tert-butyl alcohol(TBA)was developed.The polymerization of the HEMA-TBA gelcasting system,the thermal behavior of obtained green body,and the microstructures and mechanical properties of the sintered bodies were investigated by rheometer,TG-DSC,SEM and bending strength testing,respectively.The results show that,(1)10 mg/mL of the initiator(benzoyl peroxide)is the optimal amount for polymerization of this gelscasting system at 25 ℃;(2)The alumina suspension of the HEMA-TBA gelcasting system showing shear-thinning behavior is sufficiently low for gelcasting process;(3)The bending strength of porous alumina ceramic samples,whose porosities range from 42% to 56%,is from(8±0.5)to(91±4.5)MPa.

Grafting of 2-Hydroxyethyl Methacrylate onto Silk by Atom Transfer Radical Polymerization

Silk was grafted using 2-hydroxyethyl methacrylate(HEMA)by atom transfer radical polymerization(ATRP)method.The amino groups and hydroxyl groups on the side chains of the silk fibroin was reacted with 2-bromoisobutyryl bromide(BriB-Br)to obtain efficient macroinitiator for ATRP.And the macroinitiator was grafted with HEMA in water aqueous using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine(PMDETA)as catalyst system.The effects of monomer concentration,the proportion of CuBr and PMDETA,grafting temperature and time on the silk grafting were discussed,and the optimal grafting technology was obtained.FT-IR characterization of the grafted silk showed a peak corresponding to HEMA,which indicated that HEMA was grafted onto the surface of silk.ATRP method could be applied on the silk modification and this technique provided a new way for silk grafting.

Synthesis and Characterization of Poly(St-co-BA) Latex with an Organic-Inorganic Hybrid Compound as Emulsifier

A poly (St-co-BA) latex was successfully synthesized by using an organic-inorganic hybrid compound (OIHC), an aliphatic carboxylate sodium/nano-silica composite, as the emulsifier, and investigated by particle size analyzer, transmission electron microscope (TEM), optical contact angle measurement (OCA) and dynamic mechanical analyzer (DMA). It was found that the protective agent, sodium polyacrylate (PA),could obviously improve the polymerization stability and the functional monomer, glycidyl methacrylate (GMA), could enhance the store stability of the latex. The particle size of poly(St-co-BA) latex decreased and then leveled off as OIHC content increased. TEM shows that the prepared polymers were actually organic-inorganic nanocomposites, and these films have better waterproof property than those prepared by traditional poly(St-co-BA) latex or organic silicone modified poly(St-co-BA) latex. The nanocomposite polymer has much higher glass transition temperature than organic silicone modified poly(St-co-BA) polymer containing the same organic silicone content.

Relationship between the Composition of Polymer of n-Alkyl Substituted Acrylate and Vinyl Amine and Their Performance on Pour Point Depression

Polymer of n-alkyl substituted acrylate （PA） with the alkyl side chains C16- 30 were synthesized. Their crystallinity, solubility and effect on pour point depression were studied. Results showed that only carbon atoms located far away from polar groups of PAL pour point depressants participated in crystallization. When the number of carbon atoms that participated in crystallization is about three fourths of the average carbon number of wax in crude, the effect of PA is the best. The molecular weight distribution of PA pour point depressant has little influence on the effect of pour point depression, and the average molecular weight of PA in the range of （ 1.5- 2.2）× 10^4 shows the best effect. The introduction of polar groups into the molecule of PA can improve its performance. However, a too high content of polar groups in PA would cause deterioration, and even lead to loss of PA＇s performance for pour point depression.

The structure and properties of Fe_3O_4/P (NaUA-St-BA) magnetic composite nano particles

Fe3O4/P （NaUA-St-BA） core-shell composite micro spheres were in situ prepared by soapless polymerization of styrene and butyl acrylate, with Fe3O4magnetic colloidal particles coated with NaUA. The results of IR and XRD analysis demonstrated that the desired polymer chains have been covalently bonded to the surface of Fe3O4 nano particles. The morphology analysis by TEM confirmed that the composite particles have the core-shell structure and a relatively uniform diameter of about 100nm. The magnetic properties of the obtained composite latex particles were measured by VSM and found that they exhibited super paramagnetic properties. Finally, the prepared magnetic composite particles latex is stable for several months.

CONTROLLED SEQUENTIAL AND RANDOMRADICAL COPOLYMERIZATION OF STYRENE AND BUTYL METHACRYLATE BY ATOM TRANSFER RADICAL POLYMERIZATION

Diblock copolymers containing polystyrene (PSt) andpolybutyl methacrylate (PBMA)segnents and random coplymer of styrene (St) and butyl methacrylate (BMA) havebeen prepared by atom transfer radical polymerizanon (ATRP). Diblock copolymers ofBAN and St with predetermined molecular weight (1× 104ed.5 × 104)and narrowermolecular weight distribution(1.25～1.5) were obained The random copolymercompositions were determined by 1HNMR spectroscopy and the reactivity ratios wereevaluated by the extended Kelen-Tudos method to be γst=0.91, γBMA=0.32.

Removal of nickel(Ⅱ) from aqueous solutions using iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers

Iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers(PGMA-IDA/CFs) were prepared for Ni(II) removal from aqueous solutions. The effects of solution p H value, temperature and adsorption time were investigated. The maximum adsorption capacity of Ni(II) on PGMA-IDA/CFs is 0.923 mmol·L-1· g-1at pH 5.2 and 50 °C. Kinetic data indicate that the adsorption process matches the pseudo-second-order model and Elovich kinetic model. Thermodynamic data suggest that the adsorption process is endothermic spontaneous reaction.

HIGH SOLIDS-CONTENT NANOSIZE POLYMER LATEXES MADE BY A MODIFIED EMULSION COPOLYMERIZATION

Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (~30wt. %) latexes and small (~60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.

烯丙醇的生产方法

公开了一种生产烯丙醇的方法。该工艺包括丙烯、乙酸和氧反应生成反应混合物。反应混合物被蒸馏以产生包含丙烯和液体流的蒸汽流,该流体包括烯丙基乙酸、乙酸、丙烯醛和二乙酸烯丙酯。蒸馏液体流以产生包含丙烯醛的急流;含有乙酸丙烯酯。

Preparation of a pH-sensitive pantoprazole-imprinted polymer and evaluation of its drug-binding and-releasing properties

The aim of this work was to synthesize a pantoprazole-imprinted polymer(MIPs)and study its binding and release properties in an aqueous media.Methacrylic acid(MAA),methacrylamide(MAAM),hydroxyethyl methacrylate(HEMA),and 4-vinyl pyridine(4VP)were tested as functional monomers.Different solvents were also applied as polymerization media under heat or UV radiation.The optimized MIP was prepared in chloroform as a solvent,4-vinyl pyridine as a functional monomer,and ethylene glycole dimethacrylate(EGDMA)as a crosslinker monomer under UV irradiation.Binding and release properties of MIP were studied in comparison with a non-imprinted polymer(NIP)in aqueous media,at different pH values.The protective effect of polymer for drugs against acidic conditions was evaluated at pH 2.Results indicated that the MIP had superior binding properties compared to NIP for pantoprazole.The percentage of drug released from MIP was significantly less than from NIP at all pH values,which was attributed to the presence of imprinted cavities in the MIP matrix.MIP also had a stronger protective effect for pantoprazole in acidic media,in comparison with NIP.

Dual-responsive shape memory polymer arrays with smart and precise multiple-wetting controllability

Smart-controlled surface wettability from superhydrophilicity to superhydrophobicity has been extensively explored,and stimulus-responsive strategies have been widely accepted as a useful method to realize reversibility.However,achieving smart and precise wetting control remains challenging because most previous studies focused on stimulating single surface chemistry or microstructures.Herein,a dualstimulus-responsive strategy that can synergistically stimulate surface chemistry and microstructures is demonstrated on the pH-responsive molecule poly(2-(diisopropylamino)ethyl methacrylate(PDPAEMA)-modified temperature-triggered shape memory polymer(SMP)arrays.The responsive PDPAEMA and SMP can provide the surface with tunable surface chemistry and microstructures,respectively.Thus,the wetting of the surface between various states can be reversibly and precisely controlled from superhydrophilicity to superhydrophobicity with contact angle(CA)differences of less than 15° under the cooperative effect between the adjustable surface microstructure and chemistry.The surface is further utilized as a platform to create gradient wettings based on its excellent controllability.Therefore,this work presents a strategy for surface wetting control by combining tunable surface microstructures and chemistry.The prepared samples with a special wetting controllability can be applied to numerous fields,including adaptive liquid microlenses,accurate drug release,and selective catalysis.This work also proposes novel expectations in designing smart functional surfaces.

Molecularly imprinted polymer for pre-concentration of esculetin from tobacco followed by the UPLC analysis

Molecularly imprinted polymers(MIPs)for solid-phase extraction and pre-concentration of esculetin have been successfully prepared by the bulk polymerization method using esculetin as a template molecule.Polymers of varying composition were prepared using different monomers(4-vinylpyridine,methacrylic acid,and acrylamide),ethylene glycol dimethacrylate as the cross-linker,2,2-azobis(2-methylpropinitrile)as the initiator,and different porogen solvents(ethanol,acetone/methanol,and acetonitrile).The best polymer was obtained when 4-vinylpyridine was used as the monomer and acetone/methanol(3:2)as the porogen solvent,whereas the template:-monomer:-cross-linker ratio was 1:4:20.The imprinting factor of the selected MIPs for esculetin was 3.77.The polymers were evaluated according to their selective recognition properties for esculetin and structurally-related compounds(esculin,scopoletin,coumarin,and 7-methoxycoumarin).Chemical and morphological characterizations of the polymers were investigated by FTIR and scanning electron microscope,which confirmed a high degree of polymerization.Surface area,pore volume,and pore size of the polymer were investigated by Brunauer-Emmett-Teller analysis.MIPs were also successfully used as solid-phase adsorbent materials for the extraction of esculetin from tobacco leaves.Esculetin contents in dried tobacco leaves were found to be(9.27±0.17)μg g-1.

Graft polymerization of 2-hydroxyethyl methacrylate via ATRP with poly(acrylonitrile-co-p-chloromethyl styrene) as a macroinitiator

Amphiphilic graft copolymers are excellent additives for the development of antifouling membranes by nonsolvent induced phase separation. We report a convenient approach to the synthesis of novel graft copolymers with hydrophobic polyacryloni- trile (PAN) backbones and hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) side chains. Atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate was carried out with poly(acrylonitrile-co-p-chloromethyl styrene) (PAN-co-PCMS) as a macroinitiator in the presence of CuC1/2,2'-bipyridine at 50 ~C in dimethyl sulfoxide. Kinetics of the graft polymerization was also evaluated. The synthesis of poly(acrylonitrile-co-p-chloromethyl styrene-g-2-hydroxyethyl methacrylate) (PAN-co-(PCMS-g-PHEMA)) can be relatively controlled when CMS (the ATRP sites) unit in the macroinitia- tor is around 5 mol%. Both the macroinitiators and graft copolymers were characterized by FTIR, NMR and GPC. The surface morphology and wettability of the copolymer films were studied by AFM and water contact angle measurement, respectively. We demonstrate that phase segregation between the PAN-co-PCMS backbones and the PHEMA side chains takes place and the surface hydrophilicity of the graft copolymers increases with the length of the PHEMA side chains. Because these am- phiphilic graft copolymers can be synthesized in mass, they will be useful as latent additives for the fabrication of advanced PAN separation membranes.

States of Water in Hydrogels Containing with Glyceryl Methacrylate

Hydrogel materials were prepared by thermopolymerization with different content of glyceryl methacrylate and hydroxyethyl methacrylate. The different states of water in swelling hydrogels were described and studied by differential scanning calorimetry(DSC). It was found that the hydrophilicity of GMA was stronger than HEMA,the water content and bound water of GMA hydrogel are higher than HEMA hydrogel.With the increase of GMA content, the content of free water in hydrogel increased. When GMA content was lower than 50%, the increase of GMA content also increased the content of bound water; but when GMA content was higher than 50%, the increase of GMA content decreased the content of bound water, which was caused by the chain hydrogen bond formed on the GMA chain with hydroxyl group each other.