Synthesis and properties of certain polyamides based on diamines having cyclohexane rings

Kalmykova, V.D.; Bogdanov, M.N.; Okromchedlidze, N. P.; Zhmayeva, I.V.; Yefremov, V.Ya.

doi:10.1016/0032-3950(67)90151-7

Cited by 4 publications

(4 citation statements)

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“…The incorporation of cycloaliphatic monomers into polyesters and polyamides and the effects on the crystal structure and physical properties have been reported extensively. − Ridgway described isomorphism in polyamides of the type x.6 after incorporating 1,4-cyclohexanedicarboxylic acid (1,4-CHDA) . Kricheldorf and Schwarz described how incorporated 1,4-CHDA residues preferentially reside in the crystallites when they adopt a trans configuration .…”

Section: Introductionmentioning

confidence: 99%

Stereochemistry Driven Distribution of 1,4-Diaminocyclohexane Residues over the Crystalline and Amorphous Phase in Copolyamides 4.14/1,4-DACH.14. A Solid-State NMR and Temperature-Dependent WAXD Study

et al. 2005

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Following our previous study on the stereoselective cocrystallization of linear and cyclic dicarboxylic acid residues in copolyamides 12.6/12.1,4-cyclohexanedicarboxylic acid (12.6/12.1,4-CHDA, Vanhaecht et al., Macromolecules 2004, 37, 421), we have now investigated a series of copolyamides containing trans or cis isomers of 1,4-diaminocyclohexane (1,4-DACH), viz. 4.14/1,4-DACH.14. Solidstate NMR studies and WAXD experiments demonstrate that the cis isomer is present in the amorphous regions of the copolyamide, whereas the trans isomer is located in both the crystalline and the amorphous phase. Similar to the results for the trans-1,4-CHDA-based copolyamides, trans-1,4-DACH moieties are probably built into the crystalline structure with the cycloaliphatic ring oriented perpendicular to the hydrogen-bonded crystal sheets. Temperature-dependent WAXD patterns show that, unlike in the homopolyamide 4.14, a pseudohexagonal phase is not formed at the Brill temperature in the copolyamide. Instead, crossing rather than merging of the (100) and the combined ( 010)-( 110) WAXD reflections occurs upon heating of the copolyamides containing trans-1,4-DACH. In contrast to the cis isomer, introduction of trans-1,4-DACH into polyamide 4.14 raises the melting temperature, confirming the findings by solidstate NMR and WAXD analysis. Unlike 1,4-CHDA moieties, 1,4-DACH residues do not undergo thermal isomerization. Therefore, at the same amount of initially trans isomers, the copolyamides 4.14/1,4-DACH.14 exhibit higher second heating end melting points than the corresponding isomeric copolyamides 12.6/12.1,4-1,4-CHDA.

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Section: Introductionmentioning

confidence: 99%

Stereochemistry Driven Distribution of 1,4-Diaminocyclohexane Residues over the Crystalline and Amorphous Phase in Copolyamides 4.14/1,4-DACH.14. A Solid-State NMR and Temperature-Dependent WAXD Study

et al. 2005

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“…The effect of the incorporation of cycloaliphatic monomers in polyesters and polyamides has been reported quite extensively in the literature. [1][2][3][4][5][6][7][8][9][10] In previous publications, we have already discussed the partial substitution of the linear aliphatic residues with 1,4cyclohexanedicarboxylic acid (1,4-CHDA) and 1,4-diaminocyclohexane (1, in the backbone of polyamide 12.6 and polyamide 4.14, respectively. 11,12 Some preliminary differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) results on how copolymerization in the copolyamides 12.6/12.1,4-CHDA (see Figure 1) affects thermal behavior and the crystalline structure, respectively, have been communicated as well.…”

Section: Introductionmentioning

confidence: 99%

“…The effect of the incorporation of cycloaliphatic monomers in polyesters and polyamides has been reported quite extensively in the literature. − In previous publications, we have already discussed the partial substitution of the linear aliphatic residues with 1,4-cyclohexanedicarboxylic acid (1,4-CHDA) and 1,4-diaminocyclohexane (1,4-DACH) in the backbone of polyamide 12.6 and polyamide 4.14, respectively. , Some preliminary differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) results on how copolymerization in the copolyamides 12.6/12.1,4-CHDA (see Figure ) affects thermal behavior and the crystalline structure, respectively, have been communicated as well. , In these reports the possibility was coined that the more stretched trans configuration of the cycloaliphatic residues can be incorporated into the crystals of polyamide 12.6 and that as a result the melting point of the copolymer is increased compared to that of the homopolymer. In contrast, the more kinky cis configuration of the cyclic residues probably cannot be incorporated as the melting points of these copolymers do not differ significantly from that of the homopolymer.…”

Section: Introductionmentioning

confidence: 99%

A WAXD and Solid-State NMR Study on Cocrystallization in Partially Cycloaliphatic Polyamide 12.6-Based Copolymers

et al. 2003

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To study the influence of the stereochemistry on the possibility of cocrystallization of linear and cyclic aliphatic residues in copolyamides, a series of copolyamides 12.6/12.1,4-cyclohexanedicarboxylic acid with variable compositions were synthesized. From solid-state NMR studies it could be deduced that cis-1,4-CHDA is present in the amorphous regions whereas the trans residues are located in both the crystalline and the amorphous phase. WAXD patterns confirm the presence of trans-1,4-CHDA inside the crystals and reveal that the cycloaliphatic ring is most likely oriented in a direction perpendicular to the crystal sheets that contain the hydrogen bonds. As a result, the intersheet distance is increased compared to that of polyamide 12.6. Furthermore, the rings prevent the genesis of a pseudohexagonal phase above the Brill temperature. Exceptionally, crossing rather than merging of the (100) and the combined (010)−(110) WAXD reflections is observed with increasing temperature, indicating that the intersheet distances increase and become larger than the interchain distances within the hydrogen-bonded sheets before the crystals start to melt. Incorporation of trans-1,4-CHDA residues into polyamide 12.6 leads to higher melting temperatures, pointing at cocrystallization in terms of a solid solution rather than as defects. In contrast, a slight melting point depression is observed for copolymers with predominately cis-1,4-CHDA residues.

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“…The glass transition temperature was taken as the maximum in the tan 6 peak. The tan 6 curve was obtained from the plot of the loss modulus (E") divided by the dynamic modulus ( E l ) as a function of temperature (tan 6 = E"/E').…”

Section: -mentioning

confidence: 99%

Polyamides from 1,4-cyclohexanebis(ethylamine) and aliphatic dicarboxylic acids

Ridgway

1974

J. Appl. Polym. Sci.

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synopsisA homologous polyamide series of 1,4cyclohexanebis(ethylamine) (CBEA) was prepared with Cg to Clz linear, aliphatic dicarboxylic acids. Polymer and fiber properties were found to be quite dependent upon the cis and trans structure of the cycloaliphatic ring. Polyamides based on trans-l,.Q-CBEA had higher melting and higher glass transition temperatures than their cis analogs. In addition, trans polyamides were quite crystalline, whereas the cis polymers were almost completely amorphous. The boiling water shrinkage, tenacity, and moisture regain of the fibers reflected the differences in molecular fit between the cis and trans polyamides. INTRODUCTIONPolyamides containing cyclohexylene linkages have not been studied as extensively as those with phenylene linkages. Moreover, the influence of the cyclohexane ring upon polymer and fiber properties is complicated by the existence of cis and trans isomers. Interconversion of these isomeric forms can occur during melt polymerization, which dictates careful selection of intermediate materials and analysis of polymeric products. Isomerization of cis to trans structure during thermal polymerization has been reported to occur where the carboxyl group is joined directly to the cyclohexane ring.''2 Carboxyl groups separated from the ring by a methylene linkage do not cause isomerization under thermal polyc~ndensation,~ nor do amino groups, whether attached to the ring4 or separated by a methylene link.5Investigations of the cyclohexylene linkage have been concentrated primarily upon the development of heat-resistant, fibers, most of which employed cyclohexane amino acids as the starting monomer. Polyamides prepared from simple cycloaliphatic diacids and diamines have been limited primarily to diaminocy~lohexane,~~~ hexahydrophthalic acids, 1*7 and 1,4-cyclohexanebis(methylamine) .5 Unfortunately, many polyamides based on these materials are unsuitable for melt polymerization because the polymer melting points are too high.Most studies of cyclohexylene polyamide properties have been limited to melting point, solubility, or thermal stability. While such data are quite valuable, a broader investigation of structure-property relationships would be helpful.

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Synthesis and properties of certain polyamides based on diamines having cyclohexane rings

Cited by 4 publications

References 1 publication

Stereochemistry Driven Distribution of 1,4-Diaminocyclohexane Residues over the Crystalline and Amorphous Phase in Copolyamides 4.14/1,4-DACH.14. A Solid-State NMR and Temperature-Dependent WAXD Study

Stereochemistry Driven Distribution of 1,4-Diaminocyclohexane Residues over the Crystalline and Amorphous Phase in Copolyamides 4.14/1,4-DACH.14. A Solid-State NMR and Temperature-Dependent WAXD Study

A WAXD and Solid-State NMR Study on Cocrystallization in Partially Cycloaliphatic Polyamide 12.6-Based Copolymers

Polyamides from 1,4-cyclohexanebis(ethylamine) and aliphatic dicarboxylic acids

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