Polymerization of p-cresyl glycidyl ether catalyzed by imidazoles I. The influence of the imidazole concentration,the reaction temperature,and the presence of isopropanol on the polymerization

The polymerization of p-cresyl glycidyl ether catalyzed by imidazoles has been investigated as a model reaction for the polymerization of technical epoxy resins. The dependence of oligomer yield on time, temperature, and imidazole concentration, the distribution of the polymerization degrees, and the influence of isopropanol have been studied. The reaction rate and the average degree of polymerization are affected by the presence or absence of a secondary nitrogen on the imidazole, i.e., different results are obtained when 2-ethyl, 4-methyl imidazole (EMI) or 1-methyl imidazole (1-MIA) are used. 1-MIA seems to be “precursor” of the catalyst rather than a catalyst by itself. The comparisons of CGE polymerizations catalyzed by 1-MIA in the absence and presence of isopropanol show only quantitative differences: The polymerization in the presence of isopropanol is faster, and the average degree of polymerization is shifted to higher values. The activation energies of CGE polymerizations catalyzed by different imidazoles have been determined.     

二氧化硅负载壳聚糖络合铂催化烯丙基缩水甘油醚硅氢加成反应

将壳聚糖(CS)负载到SiO2上得到SiO2-CS,再与Pt配位,制得二氧化硅负载壳聚糖络合铂催化剂(SiO2-CS-Pt)。以烯丙基缩水甘油醚和三甲氧基硅烷的硅氢加成为模型反应,考察了SiO2-CS-Pt的催化性能,研究了温度、原料配比、反应时间等对目的产物的收率的影响,结果表明该催化剂具有较好的催化活性和重复利用性能。目的产物收率达59.7%,催化剂连续使用4次,活性下降不大。     

Stereoregular polymerization of glycidyl phenyl ether catalyzed by dibutyltin oxide-tributyl phosphate condensates

Summary Polymerization of glycidyl phenyl ether was carried out with the dibutyltin oxide-tributyl phosphate condensate as catalyst. The product was fractionated. The yield of the acetone-insoluble fraction was in the range of 85% to 96%. The tacticity of the polymer fractions was studied using ¹³C NMR spectroscopy. The results indicated that the microstructure of PGPE was dependent on the catalyst structure and the reaction conditions. By using the condensate of appropriate molecular weight as catalyst, the isotacticity of the acetone-insoluble fractions can reach as high as 87.4%. In some cases, however, the fractions rich in syndiotactic structure were obtained in addition to the isotactic fraction. It was suggested that more than one kind of active sites were present in the catalyst. Received: 24 September 1997/Revised version: 8 December 1997/Accepted: 15 December 1997     

Copolymerization of phenyl glycidyl ether with carbon dioxide catalyzed by ionic liquids

The copolymerization of phenyl glycidyl ether (PGE) and carbon dioxide was performed without any solvent in the presence of ionic liquid as catalyst. The reaction was carried out in a batch autoclave reactor. The carbonate content of polycarbonate was affected by the structure of imidazolium salt ionic liquid; the one with the cation of bulkier alkyl chain length and with more nucleophilic anion showed better reactivity. However, the yield of carbon dioxide addition decreased when hexyl or octyl containing ionic liquids were used in place of butyl group in 1-alkyl-3-methyl imidazolium salts. The carbonate content and turnover number (TON) of the polycarbonate increased as the reaction temperature increased from 40 to 80 ‡C. However, the carbonate content decreased with increasing reaction time.     

相转移催化法合成烯丙基缩水甘油醚

以烯丙醇和环氧氯丙烷为原料，采用相转移催化法，合成了烯丙基缩水甘油醚。研究了反应时间、反应温度、投料比及固体碱的用量对反应收率的影响。在n(烯丙醇)∶n(环氧氯丙烷)∶n(固体碱)∶n(催化剂)=1∶1.5∶1.5∶0.005、反应时间1 h、反应温度50～60 ℃时，烯丙醇缩水甘油醚收率可达88%。     

月桂基缩水甘油醚合成工艺的研究

以月桂醇和二氯丙醇为原料,在相转移催化剂四丁基硫酸氢铵(TBAHS)存在下合成了月桂基缩水甘油醚,通过测定产品环氧值的方法来计算产品的收率。采用单因素实验和正交试验相结合,考察了原料摩尔比、碱加入量、反应时间和反应温度等对月桂基缩水甘油醚收率的影响,并用1HNMR和IR等对产物结构进行了表征。正交试验极差和方差分析表明,因素影响大小依次为:原料摩尔比碱加入量反应时间反应温度,在优化工艺条件n(二氯丙醇)∶n(月桂醇)=1.2∶1,n(氢氧化钠)∶n(月桂醇)=2.2∶1,50℃下反应4 h,月桂基缩水甘油醚的收率可达81.3%。     

相转移催化法合成十二烷基缩水甘油醚

以十二醇和二氯丙醇为原料,用相转移催化剂直接合成了十二烷基缩水甘油醚。考察了催化剂种类、原料摩尔比、反应时间和反应温度对十二烷基缩水甘油醚收率的影响。结果表明,以四丁基溴化铵为催化剂,甲苯为溶剂,n(十二醇)∶n(二氯丙醇)=1∶1.60,反应温度50℃,反应时间4 h,十二烷基缩水甘油醚收率可达73.2%。用IR、1HNMR对产物结构进行了表征,采用测定产品环氧值的方法来计算十二烷基缩水甘油醚的收率。     

腰果酚基缩水甘油醚的制备及其性能研究

以腰果酚、环氧氯丙烷为主要原料,制备腰果酚基缩水甘油醚(CGE),并研究CGE/双酚A型环氧树脂(DGEBA)固化物的性能。研究表明,在CGE用量达15%时,环氧树脂固化物的机械性能达到最大值。与纯DGEBA的性能相比,复合材料的拉伸强度、弯曲强度、冲击强度分别提高了35.4%,43.3%和109.5%。随着CGE含量的增加,材料的玻璃化转变温度降低。固化微观相分离和断面出现"海岛"结构是腰果酚基缩水甘油醚的增韧机理。     

腰果酚基缩水甘油醚的制备及其性能研究

以腰果酚、环氧氯丙烷为主要原料,制备腰果酚基缩水甘油醚(CGE),并研究CGE/双酚A型环氧树脂(DGEBA)固化物的性能。研究表明,在CGE用量达15%时,环氧树脂固化物的机械性能达到最大值。与纯DGEBA的性能相比,复合材料的拉伸强度、弯曲强度、冲击强度分别提高了35.4%,43.3%和109.5%。随着CGE含量的增加,材料的玻璃化转变温度降低。固化微观相分离和断面出现"海岛"结构是腰果酚基缩水甘油醚的增韧机理。     

Polymerization of chlorophenyl glycidyl ethers. VI

Summary Polymerization of p-chlorophenyl glycidyl ether initiated by potassium glycolates (ethylene, propylene and 2-methyl propylene glycolatea) in DMSO containing some 18-crown-6 ether or glycol was investigated. For the reaction system containing the propylene glycolate asymmetrically substituted with a methyl group, relatively high polymerization rates were obtained as compared with those found for the other systems studied, the resultant polymers also having higher molecular weights and comparatively low polydispersities. Aliphatic double bonds were found to be absent in the polymers synthesized, which would suggest that in the anionic polymerization process studied the growing chain is not transferred to the monomer.Dedicated to Prof. C.I. Simionescu on the occasion of the 60th anniversary of his birthday     

New aspects in acceleration of glycidyl ether oligomerization by imidazole compounds

Summary Using simple model compounds the oligomerization of glycidyl ethers accelerated by imidazole and imidazole derivatives was investigated. The formation of oligomers depending on 1,3-diphenoxy-2-hydroxypropane as their starting compound was predominant.In the case of imidazole 1,2-dihydroxy-3-phenoxypropane and the resulting oligomers are further formed. It seems to be obvious that this reaction also occurs in the absence of water.An over-all reaction mechanism including both the main products of the glycidyl ether oligomerization formed and the different imidazole compounds investigated is proposed.     

缩水甘油β-萘基醚、正丁基醚共聚物磺酸钠的合成及表征

以硫酸为磺化剂合成了一系列不同组成的缩水甘油 β-萘基醚 -缩水甘油正丁基醚共聚物磺酸钠 ,通过控制聚醚预聚体的组成和聚醚预聚体侧链上芳基的磺化度可控制磺酸聚醚的组成 ,并用 VPO、1HNMR、IR等测定了聚醚预聚体的数均分子量与组成、磺酸聚醚的磺化度。     

超声波辐射相转移催化合成十二烷基缩水甘油醚

超声波辐射下三乙基苄基氯化铵相转移催化由十二醇与环氧氯丙烷合成十二烷基缩水甘油醚,产品用FT-IR进行结构表征。考察了催化剂的种类、反应物的摩尔比及其与催化剂和NaOH的摩尔比、超声波辐射功率和辐射时间等因素对产品收率的影响。结果表明,超声波辐射下,三乙基苄基氯化铵具有良好的催化活性,较佳反应条件为:十二醇0.15 mol,n(十二醇):n(环氧氯丙烷):n(三乙基苄基氯化铵):n(NaOH)=1:1.15:0.05:1.05,甲苯15 mL,超声波辐射功率100 W下辐射45 min,此时产品的收率达到93%以上。     

醚基功能化离子液体合成及催化烷基化反应

合成了一系列酸性的醚基功能化离子液体,对其进行了表征和测定。通过乙腈探针红外光谱法确定了最强酸性的催化剂,并将其用于催化异丁烷与2-丁烯的烷基化反应。结果表明:1-甲氧基乙基-3-甲基咪唑溴氯铝酸离子液体([MOEMIM]Br/AlCl₃)在AlCl₃摩尔比为0.75时酸性最强,催化烷基化反应效果最佳;在反应温度35℃,异丁烷与2-丁烯体积比10:1的反应条件下催化烷基化反应,可得到C₈选择性66.6%的烷基化油;其催化效果远优于非醚基功能化氯铝酸离子液体的催化效果;该催化剂可循环利用。     

The alkyl glycidyl ether as synthetic building blocks

Alkyl glycidyl ether is one of the most useful key materials for industrial applications because the addition reaction of various kinds of nucleophilic reagents to the reactive epoxy bond of the glycidyl ethers has led to glyceryl ether derivatives. Glyceryl ether exhibits many interesting physical and pharmacological properties. The alkyl glycidyl ether can presently be produced at an industrial scale under the phase-transfer catalytic Williamson ether synthesis. We have reviwwed some addition reactions of the alkyl glycidyl ether and possibilities for use as the building blocks for the syntheses of surfactants, pharmaceuticals, etc. that contain glyceryl ether skeletons. Typical examples of alkyl glyceryl ether derivatives include: amino ether as cosmetic material, and isodiglycerin mono- and dialkyl ethers and triglycerin monoalkyl ether as a cosmetic or a pharmacologically useful material, respectively. Another interesting reaction is the rearrangement of the epoxy bond of the alkyl glycidyl ether, which gives alkoxy ketone in a one-pot synthesis.     

Polymerization of bismaleimide and maleimide catalyzed by nanocrystalline titania

Polymerization of 4,4′‐bismaleimidediphenyl methane and N‐phenylmaleimide was conducted in dimethyl formamide, catalyzed by nanocrystalline titania. The monomers and polymers involved were characterized with infrared spectroscopy, ¹H‐NMR, and ¹³C‐NMR, respectively. The mechanism of the catalyzed polymerization was discussed as well. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 665–669, 1999     

离子液体催化合成双烷基二苯醚

以盐酸三乙胺/三氯化铝(Et_3NHCl-AlCl_3)离子液体为催化剂,二苯醚和1-十二烯烃为原料合成了双烷基二苯醚。通过正交试验,得到烷基化反应的较优工艺条件为:n(二苯醚):n(1-十二烯烃)=1:3,二苯醚用量0.3 mol,催化剂用量0.045 mol,反应温度70℃,反应时间1 h。在此条件下,烷基化转化率为98.1%,双烷基二苯醚选择性为33.7%。改变离子液体的阳离子和阴离子部分结构,研究了催化剂结构对其催化性能的影响。结果表明,该类催化剂的催化活性主要由阴离子部分的结构决定,较优的阴阳离子组合为Et_3NHCl-AlCl_3。     

Reaction catalyzed by montmorillonite: Polymerization of methyl methacrylate

The polymerization of methyl methacrylate (MMA) was carried out in aqueous media having various concentrations of potassium persulfate as initiator in the presence or the absence of montmorillonite (Texas) at various temperatures. The rate of polymerization increased with increasing initiator concentration. Thermal stabilities of the resulting composite materials were studied and the activation energies of polymerization and degradation were determined. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 367–372, 1997     

Composites of allyl glycidyl ether modified polyethylene and cellulose

Linear medium density polyethylene (LMDPE) was functionalized with allyl glycidyl ether (AGE) in an internal laboratory mixer in the presence of peroxide. AGE is a bifunctional monomer, which forms unstable and energetically rich macroradicals. Upon increasing the peroxide content chain scission and grafting yield were favored. The degree of functionalization was determined by means of a calibration function for Fourier-transformed infrared spectroscopy (FTIR). Grafting AGE onto LMDPE led to a small loss of crystallinity, as evidenced by differential scanning calorimetry (DSC) and X-ray diffractometry analyses. Composites of LMDPE or functionalized LMDPE-AGE and cellulose were prepared in the mixer with filler contents ranging from 20 to 50 wt%. Composites of AGE functionalized LMDPE and filler content higher than 30 wt% presented tensile properties superior to that observed for composites with unmodified LMDPE. Scanning electron microscopy (SEM) on the composites fracture surface evidenced good interfacial adhesion between LMDPE-AGE and cellulose fibers.