氯代甲酸苯氧乙基酯的合成研究

介绍了氯代甲酸苯氧乙基酯的合成方法．并重点讨论了以三光气为原料合成氯代甲酸苯氧乙基酯的方法。     

抗抑郁药奈法唑酮中间体2-苯氧乙胺的合成工艺改进

以乙腈为原料与乙醇胺反应制得 2 甲基 2 口恶唑啉 ,再与苯酚反应 ,水解得到所需产物 2 苯氧乙胺 ,对工艺进行了改进 ,收率提高到 5 1 5 % ,成本低 ,有一定的工业应用前景。     

Comparing emulsion polymerization of methacrylate-monomers with different hydrophilicity

A comprehensive experimental study concerning the influence of various types of initiator-emulsifier systems on emulsion polymerization of methacrylate monomers (2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and butyl methacrylate (BMA)) reveals interesting relations between initiator and surfactant hydrophilicity on the one hand and the hydrophilicity of the monomers on the other hand. For the water-soluble HEMA stable latexes are only obtained if hydrophobic initiators such as 2,2′-azobisisobutyronitrile or dibenzoyl peroxide in combination with alkyl sulfate surfactants with carbon chain lengths greater than 10 or surface active initiators of the 2,2′-azobis(N-2′-methylpropanoyl-2-amino-alkyl-1)-sulfonate type with alkyl chain lengths greater than 8 are employed. Stable nano size range poly(2-hydroxyethyl methacrylate) (PHEMA) particles have been prepared also by batch emulsion polymerization using ionic surface active initiators (inisurfs). The results clearly show that the formation of stable latex particles requires a proper choice of the initiator-emulsifier system regarding its hydrophilic-hydrophobic balance. The PHEMA particles prepared with surface-active initiators keep their identity and spherical shape even in the dried state whereas in the case of the other initiator-emulsifier systems complete coagulation and coalescence occurs during drying.     

Free-radical propagation rate coefficients for hydroxyalkyl methacrylates and cyclohexyl methacrylate

Free-radical propagation rate coefficients (k _p ) at 30°C for the homopolymerization of cyclohexyl methacrylate (CHMA), 4-hydroxybutyl methacrylate (HBMA), 2-hydroxypropyl methacrylate (HPMA), and 2-hydroxyethyl methacrylate (HEMA) were determined to be 1070, 917, 640, and 71.9 (L mol⁻¹s⁻¹), using the rotating-sector method. The k _p value increases rapidly, and the value of life time of free radicals (τ_s) increases smoothly with increasing the alkyl chain length in the hydroxyalkyl pendant group of the monomer. Values for the steady-illumination polymerization rate for CHMA, HBMA and HPMA are much larger than that for HEMA. Comparisons of k _p values from different sources were also made.     

Copolymers of 2-hydroxyethyl methacrylate and methyl methacrylate: an electron beam resist study

The electron beam development characteristics of copolymers of HEMA and MMA are reported. A copolymer with 4% of HEMA was found to have comparable sensitivity and enhanced contrast compared with conventional PMMA and this material would appear to be useful in lithographic applications.     

核壳乳液聚合法制备聚丙烯酸酯-聚氨酯复合乳液

以聚四氢呋喃二醇(PTMG-1000)和异佛尔酮二异氰酸酯(IPDI)为基本原料,二羟甲基丙酸(DMPA)作为亲水扩链剂,甲基丙烯酸-β-羟乙酯(HEMA)作为偶联剂与甲基丙烯酸甲酯(MMA)反应,采用核壳乳液共聚法,制备了聚丙烯酸酯-聚氨酯复合乳液(WPUA);通过红外光谱、透射电镜对WPUA乳液粒子的结构进行观察,探讨了DMPA用量、聚氨酯预聚体R值、聚氨酯(PU)链段与聚丙烯酸酯(PA)链段质量比等因素对乳液外观、粘度、稳定性等性能的影响;结果表明,当DM-PA用量为6份,R值为2.5,PU链段与PA链段质量比为70∶30时,所得WPUA表观性能较为优异。     

一种复合二氧化钛大孔共聚物的合成及其在扩张床吸附中的应用（Ⅰ）基质合成及其特性

以甲基丙烯酸缩水甘油酯和双甲基丙烯酸乙二醇酯作单体，在致孔剂存在下通过悬浮聚合将经过表面改性处理的二氧化钛超细颗粒包埋其中，制得一种密度增大的复合二氧化钛大孔共聚物（GET），作为扩张床吸附基质.研究了二氧化钛添加量、交联剂用量、致孔剂用量和配比对共聚物湿真密度和孔结构的影响.     

甲基丙烯酸2-羟乙酯的合成研究

以四甲基氢氧化铵为催化剂 ,由甲基丙烯酸甲酯和乙二醇合成了甲基丙烯酸 2 -羟乙酯。通过正交实验获得了最佳反应条件为 :反应温度 75℃ ,反应时间 4h,酯醇摩尔比 1∶ 2 .0 ,催化剂的用量为 2 .0 ml,产品收率为 91.4%。     

Dielectric analyses of a series of poly(2-hydroxyethyl methacrylate-co-2,3-dihydroxypropyl methacylate) copolymers

The dielectric spectra of a series of copolymers of 2-hydroxyethyl methacrylate (HEMA) and 2,3-dihydroxypropyl methacrylate (DHPMA) were investigated. Recently, the full range dielectric spectrum of poly(2-hydroxyethyl methacrylate) was reported. This study looks at the effects on the dielectric behavior as a result of 2,3-dihydroxypropyl methacrylate addition. The dielectric permittivity, ε′, and the loss factor, ε″, were measured using a dielectric analyzer in the frequency range of 0.6 Hz to 100 kHz and between the temperature range of −150 and 275 °C. The electric modulus formalism was used to reveal the viscoelastic and conductivity relaxations present in the polymers. Several notable changes were observed as 2,3-dihydroxypropyl methacrylate concentration increased. It was observed through DSC and DEA that the glass transition temperature decreased as DHPMA content increased. The secondary dielectric relaxations were also affected as it was recorded that the activation energy for the γ transition increased and the β relaxation decreased with DHPMA content. Ionic conductivity data prove that DHPMA facilitates ionic mobility more efficiently than HEMA.     

一种复合二氧化钛大孔共聚物的合成及其在扩张床吸附中的应用(Ⅰ)基质合成及其特性

以甲基丙烯酸缩水甘油酯和双甲基丙烯酸乙二醇酯作单体 ,在致孔剂存在下通过悬浮聚合将经过表面改性处理的二氧化钛超细颗粒包埋其中 ,制得一种密度增大的复合二氧化钛大孔共聚物 (GET) ,作为扩张床吸附基质 .研究了二氧化钛添加量、交联剂用量、致孔剂用量和配比对共聚物湿真密度和孔结构的影响     

Vapor sorption in thin supported polymer films studied by white light interferometry

In the present study, we apply a white light interferometric methodology to study sorption of moisture and methanol vapor in thin films of poly(2-hydroxyethyl methacrylate) [PHEMA] and poly(methyl methacrylate) [PMMA], supported on oxidized silicon wafers. The measured equilibrium thickness expansion of each film, exposed to different activities of the vapor penetrant, is used to determine the sorption isotherm of the system. Results for relatively thick films (100 nm < L_o < 600 nm) are compared with corresponding literature data for bulk, free-standing films, obtained by direct gravimetric methods. Furthermore, PMMA films of thicknesses lower than 100 nm were employed in order to study the effect of the dry film's thickness, and of substrate, on fractional swelling.     

Superporous poly(2-hydroxyethyl methacrylate) based scaffolds: Preparation and characterization

Superporous poly(2-hydroxyethyl methacrylate) (PHEMA) scaffolds with pore size from 10¹ to 10² μm range were prepared by radical polymerization of 2-hydroxyethyl methacrylate (HEMA) with 2 wt.% ethylene dimethacrylate (EDMA) with the aim to obtain a support for cell cultivation. Superpores were formed by salt-leaching technique using NaCl or (NH₄)₂SO₄ as a porogen. Addition of liquid porogen (cyclohexanol/dodecan-1-ol (CyOH/DOH) = 9/1 w/w) to the polymerization mixture did not substantially affect the formation of meso- and macropores. The prepared slabs were characterized by several methods including water and cyclohexane regain by centrifugation, water regain by suction, scanning electron microscopy (SEM), mercury porosimetry and dynamic desorption of nitrogen. High-vacuum scanning electron microscopy (HVSEM) confirmed permeability of hydrogel slabs to 8-μm microspheres, whereas low-vacuum scanning electron microscopy (LVSEM) at cryo-conditions showed the undeformed structure of the frozen slabs. Interconnection of pores in the PHEMA slabs was proved. Water regain estimated by centrifugation method did not include volume of large superpores (imprints of porogen crystals), in contrast to water regain by suction method. The porosities of the slabs ranging from 81 to 91% were proportional to the volume of porogen in the feed.     

Effect of sparteine on the photopolymerization of methyl and ethyl methacrylates with bis(cyclopentadienyl)titanium dichloride in a water–methanol mixture

The photopolymerization of methyl methacrylate (MMA) with bis(cyclopentadienyl)titanium dichloride (Cp₂TiCl₂) in a H₂O‐MeOH [1 : 1 (v/v)] mixture was examined at 40°C in the presence of 2,2′‐bipyridyl (Bipy), 1,10‐phenanthlorine (Phen) or sparteine (Spr) as the chelating reagent. The presence of these chelating reagents retarded the photopolymerization. Poly(MMA)s formed in the presence of them were found to contain a considerable fraction of the benzene‐insoluble part, in contrast to the ones in the absence of them. Spr was the most effective for formation of the insoluble part. The benzene‐insoluble poly(MMA) was insoluble in usual organic solvents including acetone, tetrahydrofuran, ethyl acetate, and dimethyl sulfoxide, suggesting crosslinking. However, poly(MMA) reproduced by hydrolysis of the insoluble part followed by methylation was soluble in usual organic solvents, indicating no crosslinking between polymer main chains. The insoluble part was thermally more stable than the soluble part. Polymerization of ethyl methacrylate in the presence of Spr gave similar results. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 815–822, 2001     

甲基丙烯酸2，2，2-三氟乙酯的制备及聚合

甲基丙烯酸2，2，2-三氟乙酯是一种重要的有机含氟聚合物单体，具有独特的物化性质，被广泛应用于涂料、光学纤维和接触镜片等领域。     

Synthesis and characterisation of N-toluyl methacrylatoethyl carbamates,homopolymers and copolymers with methyl methacrylate

The paper describes the synthesis of N-2/4-toluyl methacrylatoethyl carbamates using 2/4-toluyl isocyanate and 2-hydroxyethyl methacrylate. Homopolymerisation and copolymerisation of these novel monomers with methyl methacrylate was carried out using benzoyl peroxide as an initiator and tetrahydrofuran as solvent. Photopolymerisation of N-4-toluyl methacrylatoethyl carbamate could be carried out without the use of photosensitiser. Structural characterisation of copolymers was done using ¹H-NMR. Thermal stability of copolymers was evaluated in a nitrogen atmosphere by dynamic thermogravimetry.     

Effect of Silicon Monomers on the Swelling and Mechanical Properties of (PEGMA-co-HEMA) Hydrogels

A series of novel copolymeric hydrogels were prepared from 2-hydroxyethylmethacrylate (HEMA) and poly(ethyleneglycol) methacrylate (PEGMA), and silicon monomers such as trimethylsilylmethacrylate (TMSM) and 2-(trimethylsilyloxy) ethyl methacrylate (TMSOE). The effect of silicon monomer on the swelling and mechanical properties of the hydrogels was examined. The results showed that the addition of silicon monomers lowered the equilibrium water content of (PEGMA-co-HEMA) hydrogels due to their lower hydrophilicities than PEGMA and HEMA. From the swelling kinetics data, it was found that the hydrophobicity of TMSM is larger than TMSOE. The addition of TMSM effectively lowered Young's modulus and increased elongation of the synthesized hydrogels. The hydrogels containing TMSM showed pH-sensitivities, but those containing TMSOE showed a good stability in acid and base solutions.     

Differential microemulsion polymerization as a new root for entrapment of drugs

Nanosized particles derived from poly(methyl methacrylate) as well as copolymer of methyl methacrylate (MMA) and 2‐hydroxyethyl methacrylate (HEMA) were synthesized by differential microemulsion technique in the presence of ammonium persulfate as water‐soluble initiator. The polymerization was stabilized by adding biologically safe emulsifiers namely the sodium dodecyl sulfate (SDS) or polyvinyl pyrrolidone (PVP) either alone or in conjunction with polyethylene glycol. The turbidity measurements, surface tension, ζ potential, and morphological characterizations of the obtained nanosized poly MMA and its copolymer with HEMA in different monomer feed compositions were investigated. It is found that increasing HEMA content leads to increase in the particle size, turbidity measurements but the negatively charged ζ potential decreased. However, when SDS is used, the surface tension of the prepared lattices increased, whereas it is decreased by using PVP. Kinetic studies of (MMA/HEMA) in ratio of 95/5 wt % in the presence of SDS or PVP revealed that the emulsifier concentration has a considerable effect on the rate of polymerization and the power of the emulsifier. The entrapment of drug was investigated using two active molecules different in water solubility (sodium warfarin and ibuprofen). It is noted that entrapment efficiency is independent of HEMA content in the monomer feed composition but dependent on type of drug and the amount of drug introduced. Hence, higher entrapment efficiency was attained for sodium warfarin (more hydrophilic) than that of ibuprofen (more hydrophobic) and they were 95.5 and 85%, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Free-radical synthesis of narrow polydispersed 2-hydroxyethyl methacrylate-based tetrapolymers for dilute aqueous base developable negative photoresists

Novel (meth)acrylate tetrapolymers based on 2-hydroxyethyl methacrylate (HEMA) were synthesized via free-radical polymerization in refluxing xylene under monomer-starved conditions for use in negative photoresist formulations. 2,2′-Azobis(2-methylbutyronitrile) was used as initiator and 2-mercaptoethanol as chain transfer agent. Optimized resist formulations were obtained with a relatively narrow polydispersed (D=1.86) low molecular weight copolymer (M_n=1677) of 2-hydroxyethyl methacrylate (HEMA), isobornyl methacrylate (IBMA), cyclohexyl methacrylate (CHMA) and acrylic acid (AA), in a 40/30/23/7 weight ratio. A novel high-resolution single layer negative tone photoresist suitable for 193 nm and e-beam lithography that meets basic performance requirements (aqueous-base development, enhanced etch resistance, sub-0.2 μm resolution) was developed from the aforementioned (meth)acrylate tetrapolymer, the poly(2-hydroxyethyl methacrylate-co-cyclohexyl methacrylate-co-isobornyl methacrylate-co-acrylic acid) (PHECIMA) and a sulfonium salt photo acid generator. The key-components for the negative image formation (photoacid induced crosslinking) are the hydroxyl groups of the HEMA moieties. The swelling-free negative resist material was developed in diluted aqueous base [tetramethyl ammonium hydroxide, (TMAH) 0.26×10⁻²N] and presented enhanced etch resistance without the use of etch resistance promoters. 0.20-0.14 μm lines were obtained upon 193 nm and/or e-beam lithography.     

天然橡胶接枝甲基丙烯酸羟乙酯的合成与表征

以甲基丙烯酸羟乙酯(HEMA)为接枝单体,过氧化二苯甲酰(BPO)为引发剂,合成了天然橡胶(NR)接枝聚甲基丙烯酸羟乙酯(NR-g-HEMA)。研究了BPO和HEMA用量、反应温度、反应时间以及NR塑炼时间对单体转化率、接枝率和接枝效率的影响,并采用红外光谱对接枝产物进行了表征。结果表明:当BPO用量为3%,HEMA用量为30%,反应温度为80℃,反应时间和NR塑炼时间分别为4h和30min时,NR-g-HEMA的接枝率达16%。