Copolymers of anionic polymerization of octanelactam with laurolactam. II. Kinetics of isothermal crystallization

Arvanitoyannis, Ioannis S.; Kehayoglou, A. H.

doi:10.1002/apmc.1993.052040108

Cited by 6 publications

(7 citation statements)

References 12 publications

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“…The solution 13 C-NMR results showed a carbonyl peak at 185 ppm, indicating the presence of residual -caprolactam. Residual monomer is typically found in commercial samples of nylon 6.…”

Section: N6 Mol %mentioning

confidence: 97%

“…18 Qualitative analysis of the routine solution 13 C-NMR spectra showed that as the copolymer ratio changed, there was a change in peak intensity in the aliphatic region for specific peaks attributed to either nylon 6 or nylon 6,18. Quantitative NMR studies were done in the manner outlined below.…”

Section: N6 Mol %mentioning

confidence: 98%

“…Routine solution 13 C-NMR experiments used a pulse width of 7.8 s, an acquisition time of 1.3 ms, and a relaxation delay of 1 s. A minimum of 5000 scans were taken for each sample. All samples were prepared at a concentration of approximately 10 wt % in an 80 : 20 weight mixture of trifluoroacetic acid in CDCl 3 , and referenced to the center peak of the deuterated solvent triplet at ␦ ϭ 77.23 ppm.…”

Section: Characterizationmentioning

confidence: 99%

“…All solution 13 C-NMR experiments were performed on a Varian UNITY INOVA 500 MHz spectrometer operating at 125.7 MHz. Routine solution 13 C-NMR experiments used a pulse width of 7.8 s, an acquisition time of 1.3 ms, and a relaxation delay of 1 s. A minimum of 5000 scans were taken for each sample.…”

Section: Characterizationmentioning

confidence: 99%

“…Widely used copolymers are made up of nylon 6 units with nylon 6,6 monomers in various ratios. Comonomers may be entirely aliphatic [7][8][9][10][11][12][13] or may incorporate some aromatic content. 14,15 However, even in copolymer samples with reduced crystallinity, virtually all the amide linkages are fully hydrogenbonded, leading to a material with good mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of copolyamides containing octadecanedioic acid: An investigation of nylon 6/6,18 in various ratios

Bennett

Zeng

Kumar

et al. 2005

J of Applied Polymer Sci

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A series of copolyamides of various compositions of nylon 6 and nylon 6,18 were produced. Increased resistance to organic solvents resulted from greater incorporation of nylon 6,18, as shown by decreasing solubility. High-resolution solution NMR indicated there were four amide carbonyls that corresponded to the four possible pairs of comonomer units, allowing detailed composition determination. The melting points of the comonomers decreased as the ratio of hydrogen bonding amide units to methylene groups increased, going from nylon 6 to copolymers with an increasing number of nylon 6,18 repeat units.

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“…The solution 13 C-NMR results showed a carbonyl peak at 185 ppm, indicating the presence of residual -caprolactam. Residual monomer is typically found in commercial samples of nylon 6.…”

Section: N6 Mol %mentioning

confidence: 97%

Section: N6 Mol %mentioning

confidence: 98%

Section: Characterizationmentioning

confidence: 99%

Section: Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Synthesis of copolyamides containing octadecanedioic acid: An investigation of nylon 6/6,18 in various ratios

Bennett

Zeng

Kumar

et al. 2005

J of Applied Polymer Sci

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Acute hemorrhagic leukoencephalitis with severe brainstem and spinal cord involvement: MRI features with neuropathological confirmation

Pinto

Taipa

Moreira

et al. 2011

Magnetic Resonance Imaging

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Acute hemorrhagic leukoencephalitis (AHLE) is a rare and fulminant demyelinating disease considered to be the most severe form of acute disseminated encephalomyelitis (ADEM). A 70-year-old man was admitted to our emergency department (ED) after 1 week of unspecific abdominal symptoms and moderate fever in the first 3 days. Within the ED he developed a rapid onset coma and flaccid tetraparesis. Cerebrospinal fluid (CSF) analysis showed mild polymorphonuclear pleocytosis and magnetic resonance imaging (MRI) revealed supratentorial focal white matter lesions and diffuse involvement of the medulla and spinal cord. A presumptive diagnosis of ADEM was made and the patient was treated with corticosteroids followed by intravenous immunoglobulin. His neurological state did not improve and the MRI on day 8 after admission showed an increased number of lesions, mainly in the brainstem, with hemorrhagic foci. The patient died the following day and pathological features confirmed the diagnosis of AHLE. This is a unique presentation of a rare disease with detailed MRI characteristics and pathological confirmation. Although this condition is usually fatal, early recognition and aggressive therapeutic management can facilitate survival.

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Effects of different composition ratio on the dielectric relaxation and dynamic mechanical properties of poly(ω‐dodecalactam‐co‐ε‐caprolactam‐co‐propylene oxide) copolymers

Mateva

Zhilkova

Zamfirova³

et al. 2010

J Polym Sci B Polym Phys

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The molecular dynamics of new poly (ω‐dodecalactam‐co‐ε‐caprolactam‐co‐propylene oxide) copolymers (DL/CL/PAC) has been investigated by using dynamic mechanical thermal analysis (DMTA) and dielectric relaxation spectroscopy (DRS) measurements. The copolymers were synthesized via anionic polymerization of relevant lactams activated with carbamoyl derivatives of telechelic hydroxyl terminated polypropylene oxide with isophorone diisocyanate (PAC). The calorimetric, X‐ray diffraction, and DMTA measurements were performed to recognize the influence of the composition ratio and the type of PAC on the physical, thermal, and mechanical properties of the synthesized copolymers. The DRS was used to study the frequency dependence of the dielectric permittivity of some isotherms from −110 to 145 °C. Copolymerization of ε‐caprolactam with about 10 wt % ω‐dodecalactam results in a copolymer that has lower water absorption, a melting point close to that of polyamide 6 and has a high enough degree of crystallinity in respect to high storage modulus. Five dielectric relaxations have been observed in the dielectric spectra, three at lower temperature and two at higher temperature. The copolymers have two glass transition temperatures for polyamide segments and polyether blocks, indicating microphase separation in the copolymers. Other studies directed toward molecular dynamics of polyamide DL/CL/PAC copolymers have not been reported. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010

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Copolymers of anionic polymerization of octanelactam with laurolactam. II. Kinetics of isothermal crystallization

Cited by 6 publications

References 12 publications

Synthesis of copolyamides containing octadecanedioic acid: An investigation of nylon 6/6,18 in various ratios

Synthesis of copolyamides containing octadecanedioic acid: An investigation of nylon 6/6,18 in various ratios

Acute hemorrhagic leukoencephalitis with severe brainstem and spinal cord involvement: MRI features with neuropathological confirmation

Effects of different composition ratio on the dielectric relaxation and dynamic mechanical properties of poly(ω‐dodecalactam‐co‐ε‐caprolactam‐co‐propylene oxide) copolymers

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