New aspects on the mechanism of the solid state polyamidation of PA 6,6 salt

Papaspyrides, Constantine; Vouyiouka, Stamatina; Bletsos, Ioannis V.

doi:10.1016/j.polymer.2005.12.041

Cited by 30 publications

(45 citation statements)

References 16 publications

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“…In other words, it seems that NaSIPA interfered with the process by making the diffusion limitations of the water and/or HMD through the particle to the surrounding gas not so important. A relative change in the SSP mechanism was also observed in a previous study of ours, 21 in which TGA was again used as a small-scale reactor in the case of SSP catalytic runs: the presence of a catalyst changed the controlling step, which was no longer diffusion.…”

Section: Ssp Runs Of the Prepared Saltssupporting

confidence: 77%

Preparation and solid‐state polyamidation of hexamethylenediammonium adipate: The effect of sodium 5‐sulfoisophthalic acid

Vouyiouka

Koumantarakis

Papaspyrides

2007

J of Applied Polymer Sci

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The effect of sodium 5-sulfoisophthalic acid (NaSIPA) on the solid-state polymerization of hexamethylenediammonium adipate was studied. In particular, different polyamide salt grades, such as a model salt of hexamethylenediamine and NaSIPA and a polyamide 6,6 salt containing NaSIPA, were prepared through alternative procedures based on the solution-precipitation technique. Furthermore, selected salt grades were solid-state-polymerized in a thermogravimetric analysis chamber under static and flowing nitrogen. Critical reaction parameters, such as the reaction temperature, surrounding gas, and presence of NaSIPA, were investigated to determine the rate-controlling mechanism of the process. More specifically, NaSIPA significantly influenced solid-state polyamidation by reducing the reaction rate and changing the prevailing mechanism.

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Section: Ssp Runs Of the Prepared Saltssupporting

confidence: 77%

Preparation and solid‐state polyamidation of hexamethylenediammonium adipate: The effect of sodium 5‐sulfoisophthalic acid

Vouyiouka

Koumantarakis

Papaspyrides

2007

J of Applied Polymer Sci

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“…During the initial stages of DSSP of polyamide salts, some of the volatile diamine component, i.e., hexamethylenediamine (HMD), can escape, as has been observed for 66 and 610 salts and also for different aromatic polyamide salts . In a study of Papaspyrides et al . on PA66, the diamine loss was proven to precede water formation, resulting in defective surfaces on the salt crystal, thus creating the active centers necessary for the initiation and subsequent acceleration of the reaction.…”

Section: Introductionmentioning

confidence: 90%

“…The mechanism of DSSP is considered to follow a nucleation and growth model, in which defects inside the salt crystals react to polymer nuclei, gradually growing in size, according to well‐known principles of solid state chemistry . During the initial stages of DSSP of polyamide salts, some of the volatile diamine component, i.e., hexamethylenediamine (HMD), can escape, as has been observed for 66 and 610 salts and also for different aromatic polyamide salts . In a study of Papaspyrides et al .…”

Section: Introductionmentioning

confidence: 99%

Direct solid state polycondensation of tetra‐ and hexa‐methylenediammonium terephthalate: Scaling up from the TGA micro‐reactor to a laboratory autoclave

Porfyris

Papaspyrides

Rulkens

et al. 2017

J of Applied Polymer Sci

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The direct solid state polycondensation (DSSP) reaction of tetramethylenediammonium and hexamethylenediammonium terephthalate (4 T and 6 T salts) in a laboratory scale autoclave reactor was investigated. The autoclave reactor is 3 orders of magnitude larger than the TGA micro‐reactor we used previously. The larger scale reactor allows more extensive analyses such as analysis of the formed condensate by titration and allows investigation of operating conditions that are important on industrial scale, such as batch (closed system) versus semibatch (open system) operation and flow of nitrogen used. Comparing the two scales has given important insight into the parameters that are important in scaling‐up direct solid‐state polycondensation. Furthermore, the effect of scaling up on the quality of the final semiaromatic polyamide products was determined, by comparing the obtained thermal properties, the solution viscosity and the end‐group concentrations obtained by 1H‐NMR spectroscopy. When operating the open reactor with a gentle nitrogen stream, the results show that products of similar properties were obtained from the micro and the laboratory scale reactors if critical parameters like temperature and pressure time profile were kept the same. The solid character of the reacting mass was retained only when maintaining the reactor at atmospheric pressure, allowing the condensation water to be removed. When keeping the autoclave reactor closed, both polyamide (PA) products (i.e., PA4T and PA6T) were agglomerated as a result of a solid melt transition during the direct solid state polycondensation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45080.

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“…In a previous paper, we reported the synthesis of the intercalated nanocomposite based on Mg, Al-adipate LDH and polyamide 6.6 [28] through the solid state polymerization (SSP) method [29]. Previously to the SSP, polyamide 6.6 salt (PA6.6sal), a low molecular weight condensate, was obtained by a stoichiometric stepwise reaction between adipic acid (AA) and hexametilenediamine (HMDA).…”

Section: Introductionmentioning

confidence: 99%

“…Previously to the SSP, polyamide 6.6 salt (PA6.6sal), a low molecular weight condensate, was obtained by a stoichiometric stepwise reaction between adipic acid (AA) and hexametilenediamine (HMDA). In such condensation process, there is an equilibrium such as: AA + HMDA2PA6.6 salt+ H 2 O [29]. Polyamide 6.6 is an important semi-crystalline engineering polymer widely used due to its combination of properties such as high stiffness and strength at elevated temperatures, toughness, good abrasion and wear resistance, coupled with an excellent short term heat resistance due to its high melting point of $260 1C [30].…”

Section: Introductionmentioning

confidence: 99%

Structural characterization and thermal properties of polyamide 6.6/Mg, Al/adipate-LDH nanocomposites obtained by solid state polymerization

Herrero

Benito

Labajos

et al. 2010

Journal of Solid State Chemistry

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New aspects on the mechanism of the solid state polyamidation of PA 6,6 salt

Cited by 30 publications

References 16 publications

Preparation and solid‐state polyamidation of hexamethylenediammonium adipate: The effect of sodium 5‐sulfoisophthalic acid

Preparation and solid‐state polyamidation of hexamethylenediammonium adipate: The effect of sodium 5‐sulfoisophthalic acid

Direct solid state polycondensation of tetra‐ and hexa‐methylenediammonium terephthalate: Scaling up from the TGA micro‐reactor to a laboratory autoclave

Structural characterization and thermal properties of polyamide 6.6/Mg, Al/adipate-LDH nanocomposites obtained by solid state polymerization

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