Spontaneous copolymerization of N-(2-hydroxyethyl)ethyleneimine with maleic anhydride

Summary The copolymerization of N-(2-hydroxyethyl)ethyleneimine, (HEEI) as nucleophilic monomer and maleic anhydride (MA) as electrophilic monomer in the absence of initiator in acetonitrile was investigated. Copolymers were characterized by IR, ¹H-NMR and ¹³C-NMR spectroscopy. The copolymer composition depends on the monomer ratio in the feed, determined by ¹H-NMR spectroscopy. The presence of MA bridges between copolymer chains was established by spectroscopic analysis. At lower temperature the yield and molecular weight of copolymers decrease as well as the MA unit content in the copolymer.     

Copolymerization without initiator ofN-(2-hydroxyethyl)ethyleneimine with succinic anhydride

Summary Copolymers of N-(2-hydroxyethyl)ethyleneimine and succinic anhydride without initiator were prepared under different experimental conditions. The composition of the copolymers was determined by elemental analyses and¹H-NMR spectroscopy. From the results of FT-IR and¹H-NMR spectroscopy a scheme of copolymerization via zwitterion is presented which includes an esterification reaction of the pendant hydroxylic groups.     

Spontaneous copolymerization of 1-(2-hydroxyethyl)aziridine with N-phenylmaleimide and p-methoxyphenylmaleimide

Summary The copolymerization of 1-(2-hydroxyethyl)aziridine as nucleophilic monomer with N-phenylmaleimide and p-methoxyphenylmaleimide as electrophilic monomer in the absence of an initiator in solution was investigated. Copolymerizations under different experimental conditions were carried out. The copolymers were characterized by FT-IR and ¹H-NMR spectroscopy. The copolymer compositions were determined by elemental analysis and ¹H-NMR spectroscopy. Almost all products are statistical copolymers.     

N-(2-羟乙基)-邻苯二甲酰亚胺的合成研究

报道了无溶剂法合成N-（2-羟乙基）-邻苯二甲酰亚胺。邻苯二甲酸酐与乙醇胺在无溶剂的条件下反应，质量收率达到99％以上，质量分数99％以上。讨论了反应温度，反应时间，物料比例及不同后处理方式对反应质量收率和质量分数的影响。该方法操作简便，实验条件温和，后处理简便，设备投入少，无污染，适合工业化生产。     

N-(2-羟基乙基)肉桂酰胺的合成工艺研究

以肉桂酸为起始原料,经一步反应制得标题化合物.投料比为肉桂酸∶氯甲酸甲酯∶乙醇胺=1∶1.08∶2.其结构经IR、1HNMR、MS等确证,产率75%.     

Copolymerization of methylacrylate with electron-donor N-(2-hydroxyethyl) carbazolyl acrylate and n-butylacrylate with electron-acceptor (β-hydroxyethyl)-3,5-dinitrobenzoyl acrylate

Summary The radicalic copolymerization at 60° C, initiated by AIBN, in the mixture of the none chain transfer solvent benzene and the chain transfer solvent dioxane of methylacrylate with the electron-donor N-(2-hydroxyethyl)carbazolyl acrylate obeys the terminal model. The copolymerization in the same conditions of n-butylacrylate with the electron-acceptor (-hydroxyethyl)-3,5-dinitrobenzoyl acrylate failed and the desired copolymers were synthesized by radical copolymerization of n-butylacrylate with acryloylchlorid at 85° C in benzene, followed by the polymer analogue reaction with -hydroxyethyl-3,5-dinitrobenzoate in benzene/THF and with pyridine as base. The reactivity ratios of the binary system, computed in accordance with the Kelen-Tüdös method were used for constructing the copolymerization diagramm, to calculate the sequence distribution and to proof the glass transition — sequence distribution correlations.Herrn Professor Rüchardt zum 60. Geburtstag herzlich gewidmet     

The copolymerization of N-vinyl-2-pyrrolidone with 2-hydroxyethyl methacrylate

Summary The bulk free radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with N-vinyl-2-pyrrolidone (VP) was carried out to low conversions at 50 °C, using benzoyl peroxide (BPO) as initiator. The compositions of the copolymers were determined using ¹³C NMR spectroscopy. The conversion of monomers to polymers was studied using FT-NIR spectroscopy in order to predict the extent of conversion of monomer to polymer. From model fits to the composition data, a statistical F-test revealed that the penultimate model describes the copolymerization better than the terminal model. Reactivity ratios were calculated by using a non-linear least squares analysis (NLLS) and r _H = 8.18 and r _V = 0.097 were found to be the best fit values of the reactivity ratios for the terminal model and r _HH = 12.0, r _VH = 2.20, r _VV = 0.12 and r _HV = 0.03 for the penultimate model. Predictions were made for changes in compositions as a function of conversion based upon the terminal and penultimate models. Received: 27 Febuary 2001/Revised version: 5 November 2001/Accepted: 6 November 2001     

Synthesis,characterisation and properties of α,β-poly(N-2-hydroxyethyl)-dl-aspartamide-graft-maleic anhydride precursors and their stimuli-responsive hydrogels

A family of poly(amino acid)-maleic anhydride hydrogels were designed and synthesized. Water soluble polymeric precursors were prepared by partially substituting the hydroxyl groups of the α,β-poly(N-2-hydroxyethyl)-dl-aspartamide backbone with maleic anhydride, so as to provide double bonds for crosslinking and carboxylic acid groups for pH and electric field responsiveness. Reaction conditions (reactive mixture composition and catalysis) were systematically varied in order to obtain PHEA–MA precursors with different and reliable graft-maleic anhydride levels. PHEA–MA precursors were characterised by titration, Nuclear Magnetic Resonance (¹H NMR), Fourier-Transformed Infrared Spectroscopy (FTIR) and Size Exclusion Chromatography (SEC) for structural and molecular determination. Aqueous solutions of selected PHEA–MA precursors were subjected to gamma-irradiation at different irradiation doses and polymer to water concentrations in order to induce chemical crosslinking without the addition of crosslinking agents. The yield of crosslinking reactions was evaluated by solubility tests as well as the effect of ammonium persulphate, as assistant radical initiator for gamma crosslinking. Selected hydrogels were tested through swelling measurements to prove their pH and electric field responsiveness. Structural features of the different variants produced were related to the swelling behaviour.     

Copolymerization of methyl- and buthylmethacrylate with electron-donor N-(2-hydroxyethyl)carbazolyl methacrylate and electron-acceptor (β-hydroxyethyl)-3,5-dinitrobenzoyl methacrylate

Summary The radical copolymerization of methyl- and butyl methacrylates with an electrondonor monomer: N-(2-hydroxyethyl)-carbazolyl methacrylate and an electron-acceptor monomer: (β-hydroxyethyl)-3,5-dinitrobenzoyl-methacrylate respectively, in dioxane at 60°C was investigated. The reactivity ratios of the binary systems were computed by using the Kelen-Tüd?s method. The azeothropic compositions were established according to the respective copolymerization diagrams.     

Studies on graft copolymerization of 2-hydroxyethyl methacrylate onto poly(vinyl chloride)

Poly(vinyl chloride) was dehydrochlorinated in alkali solution and then grafted with 2-hydroxyethyl methacrylate (HEMA) using benzoyl peroxide as a free-radical initiator under a nitrogen atmosphere. The investigations involved examining the effects of grafting efficiency on various conditions, such as degree of dehydrochlorination, HEMA concentration, solvent effect, and reaction time. Maximum grafting to the extent of 57.2% was obtained. The mixed solvent grafting was attempted. © 1994 John Wiley & Sons, Inc.     

Graft copolymerization of unsaturated segmented polyurethanes with 2-hydroxyethyl methacrylate

Relatively high molecular weight unsaturated segmented polyurethane synthesized from poly(ethylene glycol), methylene bis(4-phenyl isocyanate), cis-2-butene-1,4-diol, and butane-1,4-diol was modified by graft copolymerization reaction. 2-Hydroxyethyl methacrylate (HEMA) monomer was grafted onto the unsaturated segmented polyurethane using 2,2′-azobisisobutyronitrile (AIBN) as initiator in N,N-dimethylformamide (DMF) as solvent. The graft copolymers were isolated by selective solvent extraction in a Soxhlet apparatus. The effect of reaction time, initiator concentration, reaction temperature, and monomer concentration on the graft yields has been examined. The graft yields were enhanced by increased monomer concentration and reaction temperature.     

Hydrogels based on copolymers of N-(2-hydroxyethyl) methacrylamide, 2-hydroxyethyl methacrylate,and 4-t-butyi-2-hydroxycyclohexyl methacrylate

A nonionic, high water content, high-strength hydrogel based on N-(2-hydroxyethyl)methacrylamide (HMA), 2-hydroxyethyl methacrylate (HEMA), and a strengthening agent, 4-t-butyl-2-hydroxycyclohexyl methacrylate (TBCM). The HMA was prepared by the reaction of methacryloyl chloride with ethanol amine. The copolymerization of HMA with varying concentrations of HEMA and TBCM resulted in transparent hydrogel films possessing a wide range of mechanical and physical properties. A copolymer composition of 79 parts HMA, 20.7 parts TBCM, and 0.3 parts ethylene glycol dimethacrylate (EGDMA) gave a transparent, flexible film possessing a water content of 72.6%, a Young's modulus of 0.45 MPa, oxygen permeability of 28 barrers, and a tear strength of 28 N/m. In contrast, a copolymer composition of 40 parts HMA, 59.7 parts TBCM, and 0.3 parts EGDMA gave a hard, transparent film possessing a water content of 33% and a modulus of 504 MPa. © 1993 John Wiley & Sons, Inc.     

Tuning the thermoresponsive properties of poly(oligo(propylene glycol) methacrylate) hydrogels via gradient copolymerization with 2-hydroxyethyl methacrylate

Gamma radiation was used to prepare copolymer hydrogel libraries based on oligo(propylene glycol) methacrylate (OPGMA) and 2-hydroxyethyl methacrylate (HEMA); a complete screening in composition of P(OPGMA/HEMA) copolymers was elaborated from 0% to 100% of OPGMA. Determination of gel fraction was performed as the first step after radiation induced synthesis. Tuning of the volume phase transition temperature (VPTT) of P(OPGMA/HEMA) copolymeric hydrogels was investigated by swelling study. Additional characterization of structure and properties was conducted by FTIR, DSC, and UV-Vis spectroscopy. All results indicate that new P(OPGMA/HEMA) copolymeric hydrogels have wide diversity in thermoresponsive properties which strongly depend on their composition.     

Poly(vinylidenefluoride)-hexafluoropropylene gel electrolytes based on N-(2-hydroxyethyl)-N-methyl morpholinium ionic liquids

Poly(vinylidenefluoride)-hexafluoropropylene (PVdF(HFP))-ionic liquid gel electrolytes were prepared by using ionic liquids based on N-(2-hydroxyethyl)-N-methyl morpholinium tetrafluoroborate and N-(2-hydroxyethyl)-N-methyl morpholinium hexafluorophosphate. TGA and FT-IR analyses confirmed that the solvent, N,N-dimethylacetamide (DMAC), used for mixing the PVdF(HFP) polymer with the ionic liquid, was almost totally removed during the gelling and drying processes. SEM photographs were taken of the surface structure of the PVdF(HFP)-ionic liquid in order to evaluate the morphology of the film’s surface according to the mixing ratio, as well as the nature of the ionic liquid. The thermal behaviors of PVdF(HFP)-ionic liquid gels were observed to be similar to those of neat ionic liquids through a DSC analysis, and the compatibility between the polymer and the ionic liquid was investigated by an XRD analysis. The ionic conductivities of all the gels were 10⁻⁴–10⁻⁸S·cm⁻¹ in a temperature range of 20°C to 70°C.     

Ultraviolet radiation-induced graft copolymerization of 2-hydroxyethyl methacrylate onto polypropylene

Polypropylene staple fibers were grafted with 2-hydroxyethyl methacrylate (HEMA) using ultraviolet radiation in the presence of three different photoinitiators, uranyl nitrate (UN), ceric ammonium nitrate (CAN), and benzoin ethyl ether (BEE), separately. The parameters of grafting were optimized for obtaining maximum graft add-on. BEE appeared to be a better photoinitiator than the other two, giving maximum possible graft add-on. CAN, as a chemical initiator, did not show significant improvement in grafting. The moisture regain of the grafted polypropylene increased in proportion with the graft add-on. Dyeing with reactive dye could give only light color to the grafted fiber. Possible explanations have been given. © 1994 John Wiley & Sons, Inc.     

Use of styrene-maleic anhydride copolymers (SMA resins) in emulsion copolymerization

The composition and quantity of styrene-maleic anhydride (SMA) copolymer resins were varied in emulsion copolymerizations of methyl methacrylate and n-butyl acrylate conducted by both batch and semicontinuous processes. The resulting particle sizes and levels of coagulum were measured to determine the optimum conditions for incorporation of the SMA resins into the resulting latexes. A semicontinuous process, in which no buffer was included and the SMA was added in a second stage comonomer emulsion, was found to produce coagulum-free latexes. These recipes, however, relied on nucleation of the polymer particles by conventional surfactants [nonyl phenol poly(ethylene) oxide and its corresponding sulfate salt] with a first-stage addition of a monomer emulsion prepared with these surfactants. SMA1000, having a 1/1 ratio of styrene to maleic anhydride in its copolymer, was determined to be the preferred resin (as opposed to SMA2000 and SMA3000, having SMA ratios of 2/1 and 3/1, respectively) because it interacted the least with conventional surfactants, which allowed its ready incorporation into coagulum-free recipes. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2729–2747, 1998     

Spontaneous copolymerization of 2-phenyl-2-oxazoline with cyclic carboxylic anhydrides

Summary The copolymers obtained by the spontaneous reaction between 2-phenyl-2-oxazoline (PhOx) and different anhydrides (succinic-SA, maleic-MA and phthalic-PA) in the absence of an added initiator have been studied. The copolymers were characterized by FTIR and ¹³C-NMR spectroscopies. Compositions were determined by quantitative elemental analysis and average molecular weights were obtained by GPC. The PhOx/MA and PhOx/PA were found to be alternating copolymers, whereas the PhOx/SA copolymer was a statistical one, rich in PhOx.     

Spontaneous cyclodehydration of N-(o-aminophenyl) amic acids

The model reaction between phthalic anhydride and 1,2-diaminobenzene was studied under conditions analogous to those of the low-temperature polycondensation of aromatic dianhydrides with bis(o-diamines) in amide solvents followed by thermal cyclodehydration in condensed state to form ladder polyimidazopyrrolones (polypyrrones). The intermediate N-(o-aminophenyl)phthalamic acid was found to undergo spontaneous cyclodehydration to give N-(o-aminophenyl)phthalimide and 2-(o-carboxy-phenyl)benzimidazole. The reaction occurred at ambient temperature in the presence of water or alcohol without using a dehydration agent. The yield of imide-amine and/or carboxy-benzimidazole depended on the temperature of the condensation reaction. Temperatures below 0°C appeared to favor the formation of the carboxy-benzimidazole. Thermal cyclization of N-(o-aminophenyl)phthalamic acid passed through the same intermediates: imide-amine and carboxy-benzimidazole. The former converted to corresponding pyrrone above 200°C, while the secondary cyclization of the latter started above 250°C. Spontaneous cyclodehydration was also observed for polyamide acid-amine precursors obtained by low-temperature polycondensation of pyromellitic dianhydride with 3,3′-diaminobenzidine. The prepolymer solutions in DMF diluted with water at room temperature turned to a gel after 48–72 h. A spectroscopic study of the resulting polymers indicated the presence of significant amounts of imide cycles. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 609–619, 1998     

Preparation and Properties of Starch-Based Film Using N-(2-hydroxyethyl)formamide as a New Plasticizer

N-(2-hydroxyethyl)formamide (HF) was synthesized efficiently and used as a new plasticizer for corn starch to prepare flexible starch film. The hydrogen bond interaction between HF and starch was proved by Fourier-Transform Infrared (FT-IR). By scanning electron microscope (SEM), starch granules were completely disrupted, and the homogeneous materials were obtained. The crystallinity of corn starch and HF-plasticized starch film (HSF) was characterized by X-ray diffraction (XRD). Water vapor permeability of HSF was higher than that of glycerol-plasticized starch film (GSF). The elongations at break of HSF were higher than those of GSF at relative humidity 33%.     

Effect of ZnCl2 on the copolymerization of acrylonitrile with N-2-chlorophenylmaleimide

Summary The effect of ZnCl₂ addition on the reactivity ratios of the system acrylonitirle (AN)-N-2-Chlorophenylmaleimide (2CMI) has been investigated. It has been found that the addition of small amount of ZnCl₂ doubles the reactivity of AN while drastically decreasing that of the 2CMI. The viscosity of the copolymers has been measured and was found to decrease with increasing the maleimide and the ZnCl₂ concentrations.