A Linear Relationship Between the 13C Ester Carbon Chemical Shift and the Melting Point or S to N Transition Temperature of n-Alkyl Esters of Biphenyl -4,4′-Dicarboxylic Acid

1983 ◽  
Vol 92 (4-5) ◽  
pp. 119-126 ◽  
Author(s):  
Jk Swadesh ◽  
Jc Poirier
Keyword(s):  
Transition Temperature ◽  
Melting Point ◽  
Chemical Shift ◽  
Dicarboxylic Acid ◽  
Linear Relationship ◽  
Alkyl Esters ◽  
Carbon Chemical Shift

scholarly journals INFLUENCE OF ENVIRONMENTAL FACTORS ON PHYSICAL-MECHANICAL PROPERTIES OF POLYDIMETHYL ETHER OF NORBORENE -2;3-DICARBOXYLIC ACID

2017 ◽  
Vol 60 (5) ◽  
pp. 68 ◽  
Author(s):  
Galina S. Bozhenkova ◽  
Alexandra N. Tarakanovskaya ◽  
Oksana D. Tarnovskaya ◽  
Roman V. Ashirov
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Hydrochloric Acid ◽  
Environmental Factors ◽  
Dicarboxylic Acid ◽  
Uv Radiation ◽  
Accelerated Aging ◽  
The Impact

The article is devoted to the production of polymer by metathesis ring-opening polymerization under the influence of ruthenium initiator of type of Hoveyda-Grubbs II generation. The monomer used the mixture of dimethyl ether norbornene-2;3-dicarboxylic acid. The monomer was prepared by the Diels-Alder reaction of dicyclopentadiene and dimethyl maleate. The polymer was prepared in bulk of the monomer mixture. In this paper we have studied the physical and mechanical properties polydimethyl ether of norbornene-2;3-dicarboxylic acid; and assessed the impact of environmental factors on the change in properties of the polymer. As environmental factors; light; UV radiation; water; 0.1 M hydrochloric acid were applied; and accelerated aging conditions; which were held in a climate chamber. During performance we found that maintaining the polymer samples in the UV light chamber led to the slight increase in flexural modulus. In contrast; the polymer storage in water and in a hydrochloric acid solution for two months resulted in a slight decrease in the modulus of elasticity in bending index. These factors did not affect the change in the glass transition temperature of the polymer. Under the conditions of accelerated aging conducted for 1; 2 and 6 days after two cycles we observed the drop in modulus for bending of 8.5%; after 6 cycles of 13%. The glass transition temperature of polydimethyl ether of norbornene-2;3-dicarboxylic acid after 6 cycles decreased by only 3.4% in the climatic chamber. Studies have shown that the resulting polymer is resistant to water; hydrochloric acid; light and UV radiation; as well as it saves properties at a sufficient level for operation at conditions of accelerated aging. It should be noted that the tested polymer was prepared without additives; stabilizers and antioxidants. The proposed polymer can be used as a structural material for machine parts; including bulky.For citation:Bozhenkova G.S.; Tarakanovskaya A.N.; Tarnovskaya O.D.; Ashirov R.V. Influence of environmental factors on physical-mechanical properties of polydimethyl ether of norborene -2;3-dicarboxylic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 68-73

Elastomer Structures and ‘Cold Crystallization’

1979 ◽  
Vol 52 (1) ◽  
pp. 207-212 ◽  
Author(s):  
M. Bruzzone ◽  
E. Sorta
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Melting Point ◽  
Natural Rubber ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Structural Defects ◽  
Strain Induced Crystallization ◽  
Induced Crystallization

Abstract In a great number of applications an ideal elastomer should satisfy, to a certain extent, both of the following requirements: (1) nearly instantaneous crystallization upon application of strain (strain induced crystallization) and (2) slow or no crystallization when cooled at the temperature of maximum crystallization rate (cold induced crystallization). A noteworthy case of (2) is elastomer crystallization in a strained state. The connection between the points (1) and (2) has not been clearly understood up to now, but it is known that some crystallizable elastomers fulfil the requirements of both (1) and (2) better than others. From an experimental point of view, cold induced crystallization kinetics are substantially easier to measure than those of very fast strain induced crystallization. The phenomenon of cold induced crystallization in natural rubber, NR, has been known since the very beginning of elastomer technology and the tendency of natural rubber to crystallize by cooling has been overcome by crosslinking it with sulphur (vulcanization) without impairing its ability to crystallize by stretching (Goodyear, 1836). The synthesis of cis-polyisoprenes (IR) and cis-polybutadiene (BR) of different microstructural purity (different cis content) gave the possibility of changing the crystallization rate. It has also been reported that the very fast cold crystallization of trans-polypentenamer (TPA) could be reduced by lowering the trans content. The same fact had been observed earlier for trans-polychloroprene. There is a general agreement in postulating that the reduction of the crystallization rate, obtained either by cross-linking or by chain regularity reduction, can be linked with the lowering of the melting point. In both cases the low level of structural defects introduced in the chains does not affect the glass transition temperature in such a way as to vary the crystallization rate. The aim of this paper is to emphasize the importance of the variations of the glass transition temperature and melting point on the elastomeric cold crystallization rate and the way these may be used in planning new elastomer structures.

Deshielding γ–gauche effects in 13C magnetic resonance: a comparison of the conformational behaviour of the acetyl group in cyclohexane and 5-substituted-1,3-dioxane systems

1984 ◽  
Vol 62 (7) ◽  
pp. 1308-1311 ◽  
Author(s):  
G. W. Buchanan ◽  
S. H. Preusser ◽  
V. L. Webb
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Low Temperature ◽  
Direct Measurement ◽  
Carbonyl Carbon ◽  
Acetyl Group ◽  
Carbon Chemical Shift ◽  
Reported Data

Low temperature (173 K) 13C spectra of acetylcyclohexane, 1-acetyl-1-methylcyclohexane, and 5-acetyl-5-methyl-1,3-dioxane are reported. Data permit the first direct measurement of −ΔG0 for the acetyl group bonded to cyclohexane. The value obtained, 1.02 ± 0.05 kcal/mol in CS2–CD2Cl2 solution, is considerably lower than that determined by equilibration methods. Factors contributing to observed axial–equatorial carbonyl carbon chemical shift differences for substituted cyclohexanes and 1,3-dioxanes are discussed.

Total assignment of the carbon-13 NMR spectrum of the cembranoid diterpene eunicin through the use of two-dimensional proton-carbon chemical shift correlation

1984 ◽  
Vol 106 (6) ◽  
pp. 1823-1826 ◽  
Author(s):  
Robert T. Gampe ◽  
Maktoob Alam ◽  
Alfred J. Weinheimer ◽  
Gary E. Martin ◽  
James A. Matson ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Two Dimensional ◽  
Chemical Shift Correlation ◽  
Nmr Spectrum ◽  
Carbon Chemical Shift

ChemInform Abstract: Long Range Optimized Two-Dimensional Proton-Carbon Chemical Shift Correlation.

1986 ◽  
Vol 17 (19) ◽  
Author(s):  
M. J. QUAST ◽  
E. L. EZELL ◽  
G. E. MARTIN ◽  
M. L. LEE ◽  
M. L. TEDJAMULIA ◽  
...  
Keyword(s):  
Chemical Shift ◽  
Long Range ◽  
Two Dimensional ◽  
Chemical Shift Correlation ◽  
Carbon Chemical Shift

Solvent Effect Correlations for Acetone: IR versus NMR Data for the Carbonyl Group

1989 ◽  
Vol 43 (6) ◽  
pp. 1049-1053 ◽  
Author(s):  
R. A. Nyquist ◽  
C. L. Putzig ◽  
D. L. Hasha
Keyword(s):  
Hydrogen Bonding ◽  
Chemical Shift ◽  
Solvent Effect ◽  
Linear Relationship ◽  
Carbonyl Group ◽  
Mixed Solvent ◽  
Nmr Data ◽  
Chemical Shift Data ◽  
The Relationship ◽  
Shift Data

A linear relationship is found to exist between the carbonyl stretching frequency ( vC=O) and the carbon-13 chemical shift data [δ(13C=O)] for the carbonyl group of 0.345 mole % acetone in a mixed solvent solution ranging from 1.5 to 70.8 mole % CHCl3/CCl4. The correlation shows that as vC=O decreases in frequency δ(13C=O) increases in frequency as the concentration of CHCl3 increases in the acetone/CHCl3/CCl4 solutions. However, the relationship between vC=O and the mole % CHCl3/CCl4 and between δ(13C=O) and the mole % CHCl3/CCl4 is not linear over the concentration range studied. Both hydrogen bonding and bulk dielectric effects most likely contribute to the change in both the IR and NMR data with change in the CHCl3/CCl4 ratio.

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