Degree Of Cyanoethylation Research Articles

Evaluation of processing temperature in the production of fibre reinforced epoxy composites

Abstract A group of cyanoethylated amine (CEA) has been synthesized by carefully reacting triethylenetetramine with varying proportions of acrylonitrile. Such CEAs were utilized as hardener for the curing of epoxy resin. The effect of cyanoethylation of amine on their curing reaction with epoxy resin has been studied by differential scanning calorimeter (DSC). The processing temperature for the fabrication of composite is estimated from the DSC analysis with an approach to satisfy the logical selection of temperature for application of pressure during processing of a composite structure. The exotherm of such curing reaction (ΔHex) and the degree of cyanoethylation (CEt) of the amine follow the relation ΔHex = (324–68.40 CEt) J g−1.

Study of the Influence of Reaction Conditions for Production of Cyanoethylcellulose from Cellulosic Material from Bamboo ( Dendrocalamus strictus )

ABSTRACT Bamboo, a lignocellulosic material, is a renewable resource of interest as feedstock for production of cellulosics by chemical functionalization. The present paper describes the cyanoethylation of cellulose isolated from Dendrocalamus strictus bamboo in which the effect of different reaction conditions was studied with respect to maximum degree of cyanoethylation. Optimum conditions for preparation of a fibrous and organosoluble cyanoethylcellulose (DS 2.2) comprised of aqueous NaOH concentration 12%, alkalization temperature 20°C, acrylonitrile concentration 90 mol/AGU, cyanoethylation time 0.75 h and temperature 55°C.

Decrystallization of jute by cyanoethylation

AbstractThe cyanoethylation of jute fiber was studied at different reaction conditions. Moisture regain decreased significantly on cyanoethylation. Introduction of 5–6% nitrogen content on the fiber minimized the moisture regain capacity to 2.8%. A further increase in the nitrogen content increased the moisture regain. The effect of cyanoethylation on infrared absorption was studied. The absorbance curves of OH and CH stretching frequencies are parabolic in nature, whereas β‐glycosidic and CH bending absorption curves are almost linear with an increase in the degree of substitution. The cellulosic transition was indicated by the lattice conversion ratio, which showed an increase along with the degree of cyanoethylation. © 1993 John Wiley & Sons, Inc.

Cyanoethylated cellulose prepared by homogeneous reaction in paraformaldehyde‐DMSO system

AbstractA series of cyanoethylated celluloses with various degrees of substitution was prepared by homogeneous reaction of cellulose in PF/DMSO system. Their thermal deformation properties changed regularly with the degree of cyanoethylation. By comparing highly cyanoethylated cellulose in the series with that prepared by a traditional cyanoethylation method, it was seen that they were quite different in physical properties such as thermal deformation or tensile properties. Based on the results of dynamic mechanical measurements and infrared spectroscopy, cyanoethylated cellulose prepared in PF/DMSO system was found to be a new cellulose derivative, which includes oligo‐oxymethylene groups at the position between the glucopyraneose ring and the cyanoethyl group in the side chain. The maximum DS value of this cyanoethylated cellulose was estimated to be ca. 2.5.

Preparation and properties of cyanoethylated insulin. An insulin derivative with blocked amino- and imidazole-groups.

Acrylonitrile has been shown to react not only with α‐ and ɛ‐amino groups, but also with imidazole‐nitrogens in beef insulin. Experimental methods are described for the preparation and analysis of insulin derivatives with cyanoethylated amino groups and various amounts of cyanoethylated histidine residues. Cyanoethylated derivatives of insulin can be separated from insulin by electrophoresis. Cyanoethylated insulin represents a mixture of different molecular species as shown by ion exchange chromatography. Residual histidine and carboxyethyl‐histidine residues were determined in acid hydrolysates of the isolated peptides B 1–7 and B 8–19. The amounts of blocked histidine B 5 were found to be greater than those of histidine B 10 by a factor of 2.7–3.6. Under the applied experimental conditions immunological properties of cyanoethylated insulin with a residual histidine content of 50% are similar to those of the native hormone. Depending on the degree of cyanoethylation, cyanoethylated insulin has a biological activity of 50–20% of that of insulin. Evidence is presented for the important role of histidine residues for biological activity of insulin. The data presented suggest that histidine B 5 be particularly important.

Cold water‐soluble films from cyanoethylated polyvinyl alcohol

AbstractThe cyanoethylation of polyvinyl alcohol and the merits of using NaCN as the catallyst are discussed. The application of cyanoethylated PVA to cold water‐soluble films is specifically discussed. The use of NaOH catalysis was found to lead to nitrile hydrolysis which resulted in humidity‐susceptible films. By using NaCN catalysis, it was found that the reaction temperature and per cent solids could be increased resulting in a decrease in undersirable by‐product formation. It was found that films could be cast from cyanoethylated PVA with a degree of cyanoethylation between 5 and 10 mole‐% which were readily soluble in cold water and which had physical properties very similar to several commercial water‐soluble films.

The Dielectric Properties of Cyanoethylated Polyvinyl Alcohol

Polyvinyl alcohol was reacted with acrylonitrile (i.e., cyanoethylated) to obtain a series of polymers differing in degree of cyanoethylation . Dielectric constants (ε′) and of these cyanoethylated polyvinyl alcohols were measured from 60 cps to 300 kcps and −50° to 75°C; d‐c volume resistivities (ρ) were measured at 25°C. Unusually high dielectric constants were observed; however, the losses did not develop dispersion peaks within the frequency range studied even on cooling the polymers to −50°C. In general, ε′ and first decreased slightly with increasing cyanoethylation, then increased and reached plateaus or maxima at 30 to 40% Cross linking the polymer had little effect on dielectric properties when the was high, but lowered ε′ and ε″ and increased ρ when the was low; these changes were greatest with unmodified polyvinyl alcohol . Polar group substitution presumably accounts for the observed variations in dielectric properties.

44—CHEMICAL MODIFICATION OF WOOL: I. Cyanoethylation

A study has been made of the cyanoethylation (CNE) of wool with liquid and gaseous phases of acrylonitrile (AN), using KCN. acetic acid, etc., as catalysts. Results of practical interest are as follow. The gaseous process shows a greater degree of CNE (DCNE) than does the liquid process, attaining a maximum of ca. 6·0g-equiv. CH2: CH·CN/104g wool. NaCN. NaOH, triethanolamine, and boric acid are also used as catalysts for gaseous CNE, but all these catalysts show a lower DCNE except NaCN, which is as effective as KCN. Preformalized wool shows a lower DCNE than does untreated wool. When wool is cyanoethylated in the gaseous phase, using KCN as catalyst, wool shrinkage diminishes remarkably. Breaking strength increases and alkalisolubility remains unchanged, but there is no marked change in respect to moth-proofing. The effect on dyeing properties of the introduction of cyanoethyl groups into wool keratin, using KCN and acetic acid as catalysts, is discussed.

Cyanoethylation of Cotton in Aqueous Medium

An investigation was made of the cyanoethylation of cotton using small quantities of acrylonitrile dissolved or dispersed in aqueous sodium hydroxide solution. As com pared with conventional processes, the rate of reaction and the maximum degree of cyanoethylation were both found to be lower. The losses of acrylonitrile in side reactions were relatively small and approached the minimum obtainable in the best processes previ ously reported. A study of the physical properties of the product showed the im portance of reaction conditions in determining the properties of cyanoethylated cotton.

PREPARATION OF SYNTHETIC FIBERS FROM A MIXTURE OF POLYVINYL ALCOHOL AND POLYVINYL CYANOETHYLETHER

Easily dyeable fibers can be obtained from a solution of a mixture of polyvinyl alcohol and polyvinyl cyanoethylether whose degree of cyanoethylation is lower than 25 mol percents. The mechanical properties of these fibers are similar to the ordinary vinylon.