Strength of polyethylene and capron as a function of stretch ratio

The relation between the strengths and stretch ratios of a capronmonofilament and a high-pressure polyethylene film has been investigated for various stretching temperatures and stretching rates. The strength, measured at –196°C (_–196), is directly proportional to the stretch ratio (). For a given , _-196 does not depend on stretching temperature and stretching rate. The breaking load at –196° C (for a given initial cross section of the starting unoriented specimen) does not vary with . A possible explanation is offered.Mekhanika Polimerov, Vol. 3, No. 4, pp. 591–595, 1967     

Biological activity of furan derivatives (review)

Information on the biological activity of furan derivatives for the period 1981–1991 is correlated. The promising character of the study of the biological properties of furan derivatives for the creation of new medicinals is demonstrated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 291–321, March, 1993.     

Multiwall carbon nanotubes and their applications

The chemical, electrophysical, magnetic, tribological, and physicomechanical properties of multiwall carbon nanotubes (MWCNTs), as well as the characteristics of new nanocomposites and instruments thereof were discussed. These MWCNTs are produced by unique technology and are free from impurities of other carbon modifications. Advantages of multiwall over single-wall carbon nanotubes were demonstrated for applications in electronic devices and preparation of nanocomposites (as filling agents).     

Synthesis and neurotropic activity of silyl-substituted fufural thiosemicarbazones

5-Silyl-substituted-2-furaldehyde thiosemicarbazones were prepared by the condensation of the corresponding furfurals or furfural diethylace-tals with thiosemicarbazide. The neurotropic activity of the synthesized thiosemicarbazones has been studied. The majority of the compounds examined possess high or medium neurotropic activity of the depressant type. They also show antihypoxic activity and decrease the duration of phenamine stereotype behaviour. Structure-activity correlation has been found.     

Investigation of 2,5-disubstituted silylfurans by PMR spectroscopy

The¹H,¹³C, and²⁹Si NMR spectra of S-substituted furfurals and the corresponding diethyl acetals containing various alkylsilyl substituents at position S of the furan ring were studied in comparison with the carbon- and sulfur-containing analogs and also with a series of monosubstituted silylfurans. In cases where the substituent was conjugated with the residue of the furan molecule the effect of the substituent at position S of the furan was transmitted to C of the aldehyde group. The reverse effect was also observed. It was determined that the contribution from the aldehyde group and the substituents at position S of the furan to the screening of the carbon nuclei of the furan ring was not additive.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 449457, April, 1996.     

Hydrosilylation of unsaturated compounds with 5-dimethylsilylfurfural diethyl acetal

Hydrosilylation of terminal acetylenes, HC≡CR (R = CMe₃,n-C₇H₁₅, SiMe₃, Ph, COOEt, CH₂N(CH₂)₄, and CH₂N(CH₂)₅) with 5-dimethylsilylfurfural diethyl acetal (1) gives a mixture of products of bothtrans-β- and α-addition. When R = CMe₃ or SiMe₃, the reaction proceeds regio- and stereospecifically to give only thetrans-β-derivatives. The formation of β-adducts is favored by pronounced electron-donating substituents and steric hindrance at the C_α atom. Terminal alkenes, H₂C=CHR (R = CH₂CN, CH₂N(CH₂)₄, CH₂N(CH₂)₅, SiMe₃, SiMe(α-furyl)₂, SiMe₂(α-furyl), SiMe₂(α-thienyl), and SiMe₂(5-chloro-2-thienyl)), react with silane1 to give only the products of β-addition; the reaction of1 with H₂C=CHCH₂NHC₆H₁₃-n affords a mixture of β- and α-adducts in a ratio of 1.8∶1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1784–1788, October, 1993.     

Synthesis and Neurotropic Activity of 5-Substituted Furfural Thiosemicarbazones

Abstract

5-Substituted-2-furaldehyde thiosemicarbazones were prepared from furfurals and thiosemicarbazide using the condensation method. The neurotropic activity of the synthesized thiosemicarbazones has been evaluated. The majority of the compounds examined has been shown to possess high or medium neurotropic activity of the depressant type. Structure-activity relationships of the titled compounds have been studied as well.