Iodine reaction of vinyl acetate/vinyl propionate copolymers. III. Iodine affinities of the radically polymerized copolymers and the copolymers derived from partially saponified polyvinyl acetate

Hirai, Toshihiro; Kajikawa, Masao; Tanaka, Makoto

doi:10.1002/apmc.1977.050570101

Cited by 6 publications

(1 citation statement)

References 19 publications

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“…The formation of the PVAc-iodine complex itself was described in the literature. − However, most of these studies were about the iodine complex formed in the aqueous solutions. Even now, however, we do not know whether the amorphous PVAc forms a solid-state iodine complex and whether these solid complexes are crystalline or not.…”

Section: Introductionmentioning

confidence: 99%

Crystalline Iodine Complexes of Amorphous Poly(vinyl acetate) as Studied by X-ray Diffraction, Vibrational Spectroscopy, and Computer Simulation

2020

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One of the typical amorphous polymers, atactic poly(vinyl acetate) (PVAc) has been found to form the two types of crystalline iodine complexes (α and β forms) with iodine ions when the sample is immersed into the iodine aqueous solutions of low and high concentrations (0.001−0.01 and 0.04−3 mol/ L), respectively. By analyzing the experimental data of resonance Raman spectra and X-ray 00L diffractions, the iodine species were identified as I 5− ions in the β form, and the mixture of I 3 − and I 5 − ions was in the α form. The quantitative analysis of the two-dimensional X-ray diffraction data combined with the density functional theory (DFT) calculation gave the two representative models for the iodine complex: in one model (interchain iodine model), the helical PVAc chains of irregular configuration are arrayed side by side, and the iodine columns are sandwiched between these chains. Another model (intrachain iodine complex model) consists of the doubly stranded helices of PVAc chains, inside which the I 5 − (and I 3 − ) ions are confined along the chain axis. Both of these two models reproduced the observed X-ray diffraction data well, suggesting the hybridized model of these two candidates as the more realistic complex model. The details of the packing mode of PVAc chains and iodine columns in the complex are different between the α and β forms. The occupancy of iodine ions is also different between the α and β forms. It is emphasized that the amorphous PVAc chains can form the crystalline complexes with iodine ions although the PVAc chains themselves are totally irregular in configuration. The stabilization mechanism of the iodine complexes of the structurally irregular PVAc chains was discussed on the basis of DFT calculation.

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Section: Introductionmentioning

confidence: 99%

Crystalline Iodine Complexes of Amorphous Poly(vinyl acetate) as Studied by X-ray Diffraction, Vibrational Spectroscopy, and Computer Simulation

2020

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Untersuchungen zur Komplexbildung von Vinylalkohol‐Vinylacetat‐Copolymeren mit lod in Gegenwart von lodid

Heublein

Meißner

1981

Acta Polymerica

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Die Acetylgruppenverteilung in Vinylalkohol-Vinylacetat-Copolymeren wird mittels der Extinktionen der Komplexbildung rnit Iod in Gegenwart von Iodid untersucht. In Abhangigkeit vom Restacetylgruppengehalt werden Maximakurven erhalten, die in guter Ubereinstimmung rnit der Wasserloslichkeit und den Dispergiereigenschaften der Copolymere stehen. Die Produkte rnit den besten Dispergiereigenschaften haben die hochsten Extinktionswerte. Bei statistischen Copolymeren erreichen die Extinktionen bei Acetylgruppengehalten urn 12 M01-y~ Werte von maximal 0,1, wahrend rnit zunehmender Blockverteilung der Acetylgruppen eine Erhohung auf 0,5 erfolgt, bei gleichzeitiger Verschiebung zu Restaoetylgruppengehalten um 20 M01-y~. Da sich die Dispergiereigenschaften von Blockcopolymeren nur wenig von denen statistischer Copolymere unterscheiden, kann die Methode der Komplexbildung im Gegensatz zur Literaturdarstellung nicht als MaB fur die Dispergiereigenschaften verwendet werden. Mccaaoeanue 1~0~n n e l~~o o 6 p a~o e a n u~z . w w d y cononu.uepancu sununoeoeo cnupma u eununaqemama c uoaoM e npucymcmauu uoauaa BccnegosaHo pacnpexeneme aqeTunbmx rpynn B cononmepax BuHmoBoro cnHpTa II BuHHaaqeTaTa c nomoqbm 3KCTHHKqHfi IIpU KOM~J'RKC006pa30BaHHH C HOHOM B IIpUCyTCTBHH HORHRa. B 3aBHCHMOCTH OT CORepmaHHR OCTaTOYHbIX aqeTUJIbHbIX rpynn IIOJIyqeHbI 8KCTpeMaJlbHbIe KpHBbIe, XOpOrUO COOTBeTCTByIO~He BOAOPaCTBOPHMOCTU H AHCIIeprSipyeMOCTH COIIOJIUMepOB. 06pa3qb1 C MaKCHMaJIbHOfi ~HCneprHpyeMOCTbIO MMeIOT MaKCHManbHble 3Ha-YeHHR aHCTHHKqHH. AJIR CTaTHCTH4eCKHX GOIlOnHMepOB aKCTUHKqHR IlpH CO~epXaHHH aqeTHJIbHbIX I'pyIIn OHOJIO 12 MOJIbH.% ROCTHPaeT 3HaYeHHR MaKCHMyM B 0,1, B TO BpeMR K a K C B O 3 p a C T a l O~H M OTHJIOHeHHeM OT CTaTEICTHYeCKOrO paCnpegeJIeH%iR aqeTUJIbHbIX rpynn HMeeT MeCTO YBeJIHYeHEle 8KCTHHKqHEl A 0 0,5 IIpH ORHOBpeMeHHOM IIOBbIIUeHUM OCTaTOYHOI'O COJ(ep?KaHHR WeTHJIbHJdX rpyIIIl A 0 npHMepH0 20 MOJIbH.%. BBHAY TOFO, YTO AHCUepI'SipJ'eMOCTb 6 n o~-c o n o~1 u~e p o~ TOJIbKO Man0 OTJIHYaeTCR OT TaKOBOfi CTaTUCTUYeCKUX COIlOJIHMePOB, MeTOR ~o~n~1 e~c o o 6 p a s o -BBHHR, B IIpOTUBOnOJTOmHOCTb K JIHTepaTypHbIM AaHHbIM, HeJIb3R nPHMeHRTb AJIR OqeHKU AIlCIIeprUpyeMOCTU. Investigation of the complex formation of vinylalcohol-vinylacetate copolymers with iodine in the presence of iodideThe acetyl group distribution of vinyl alcohol-vinyl acetate copolymers is investigated by means of the extinctions of the complex formation with iodine in the presence of iodide. Depending on the remaining acetyl group content maxima curves are obtained, which are in a good agreement with the water solubility and the dispersion properties of the copolymers. The products with the best dispersion properties show highest values of extinction. The extinctions of statistical copolymers reach values a t most 0.1 with acetyl group contents of 12 mole yo, while in the case of more blocky distribution of the acetyl groups an increase to 0.5 occurs, with a simultaneous shift to remaining acetyl contents of about 20 mole %. Due to ehual dispersion pr...

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Iodine reaction of vinyl acetate‐vinyl propionate copolymers, VI, thermochromism of the iodine complex membranes of poly(vinyl acetate) and vinyl acetate‐vinyl propionate copolymers

Tanaka

Mizutani

1979

Angew. Makromol. Chem.

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The thermochromism of the iodine complex membranes of poly(viny1 acetate) and vinyl acetate-vinyl propionate copolymers was investigated at the states of different humidity. The complex membranes which were maintained in water and in wet air showed a reversible colour change by a heating-cooling cycle, while the complex membrane in dry air was irreversibly decoloured by heating. The decolouration of the complex membranes occurred quite sharply at a temperature characteristic of each membrane.

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Iodine reaction of vinyl acetate/vinyl propionate copolymers. III. Iodine affinities of the radically polymerized copolymers and the copolymers derived from partially saponified polyvinyl acetate

Abstract: Die Ergebnisse stutzten nicht nur die Existenz der ReiBverschIuB-Reaktion, die fur Verseifungen von PVAc bei hohem Umsatz bekannt ist, sondern deuteten auch an, daB die Verseifung des PVAc bei niedrigem Umsatz vom Wassergehalt im Losungsmittel und der Verseifungstemperatur beeinfluBt wird.

Cited by 6 publications

References 19 publications

Crystalline Iodine Complexes of Amorphous Poly(vinyl acetate) as Studied by X-ray Diffraction, Vibrational Spectroscopy, and Computer Simulation

Crystalline Iodine Complexes of Amorphous Poly(vinyl acetate) as Studied by X-ray Diffraction, Vibrational Spectroscopy, and Computer Simulation

Untersuchungen zur Komplexbildung von Vinylalkohol‐Vinylacetat‐Copolymeren mit lod in Gegenwart von lodid

Iodine reaction of vinyl acetate‐vinyl propionate copolymers, VI, thermochromism of the iodine complex membranes of poly(vinyl acetate) and vinyl acetate‐vinyl propionate copolymers

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