Preparation of highly isotactic poly(vinyl alcohol)

Ohgi, Hiroyuki; Sato, Toshiaki

doi:10.1021/ma00055a025

Cited by 44 publications

(30 citation statements)

References 1 publication

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“…PV A having high isotacticity (PV A-II) was prepared by cationic polymerization of t-butyl vinyl ether with boron trifluoride etheraie at -78°C followed by cleavage of the ether linkage of this polymer using hydrogen bromide at 0°C. 9 This PV A had residual ether groups at less than 0.1 mol¾.…”

Section: Pva Samplesmentioning

confidence: 92%

Biodegradation of Poly(vinyl alcohol) with High Isotacticity

Fukae

Fujii

Takeo

et al. 1994

Polym J

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ABSTRACT:A bacterium having biodegrading activity with poly(vinyl alcohol) (PVA) was isolated from an activated sludge sample of a textile dyeing factory which deals with PV A. The bacterium was identified as a strain of Pseudomonas sp. and designated strain A-41. The results of the degradation of commercial PVA having atacticity altered triad-isotacticity from 21 % to 13%. This suggests that the isotactic sequences in PVA are susceptible to biodegradation preferentially. PVA with high isotacticity was found to be easily degraded in comparison with commercial PV A.KEY WORDS Poly(vinyl alcohol) / Stereoregularity / Biodegradation / Pseudomonas / Isotacticity / Chain Scission / Suzuki et al. investigated the biodegradation ofpoly(vinyl alcohol) (PV A) using a bacterium, Pseudomonas 0-3 and this bacterium was used for treating wastewater which contains PV A.

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Section: Pva Samplesmentioning

confidence: 92%

Biodegradation of Poly(vinyl alcohol) with High Isotacticity

Fukae

Fujii

Takeo

et al. 1994

Polym J

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“…[10][11][12] We found interesting features of these highly isotactic PVAs (HI-PVAs) being different from those of LI-PVA and ordinary atactic PVA (A-PVA). 10,13,14 In particular, we compared the melting temperature T m , degree of crystallinity c , and 13 C spin-lattice relaxation time T 1C of the crystalline components for PVA samples with different tacticities (including HI-PVA) to find that these physical quantities show clear minima at the mm fraction = 0.4-0.5 when plotted against mm.14 This result suggests that the structural disordering associated with the decrease in the crystallinity occurs most significantly in this mm range. In relation to these minima, FT-IR spectroscopy confirmed the formation of the new crystal form for HIPVAs with mm > 0:55 and solid-state 13 C NMR spectroscopy revealed that all OH groups are allowed to form successive intramolecular hydrogen bonding along the respective chains in the crystalline region for HI-PVAs with mm > 0:7.…”

mentioning

confidence: 79%

“…OEt 2 ) and successfully prepared the PVAs having the highest isotacticity so far reported. [10][11][12] We found interesting features of these highly isotactic PVAs (HI-PVAs) being different from those of LI-PVA and ordinary atactic PVA (A-PVA). 10,13,14 In particular, we compared the melting temperature T m , degree of crystallinity c , and 13 C spin-lattice relaxation time T 1C of the crystalline components for PVA samples with different tacticities (including HI-PVA) to find that these physical quantities show clear minima at the mm fraction = 0.4-0.5 when plotted against mm.…”

mentioning

confidence: 79%

“…In this determination, the ÁH c value for the 100% crystallinity (ÁH c ¼ 6:87 kJ mol À1 ) 24 is often assumed to be independent of the stereoregularity. However, the crystal structure of HI-PVA differs from that of S-PVA and A-PVA, 10 and no ÁH c data have been reported for HI-PVA.…”

Section: Density Swelling and Thermal Behavior Of Pvasmentioning

confidence: 97%

“…9, 10 Recently, we studied the cationic polymerization of tBVE with boron trifluoride diethyl etherate (BF 3 . OEt 2 ) and successfully prepared the PVAs having the highest isotacticity so far reported.…”

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confidence: 99%

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Highly Isotactic Poly(vinyl alcohol) Derived from tert-Butyl Vinyl Ether V. Viscoelastic Behavior of Highly Isotactic Poly(vinyl alcohol) Films

Ohgi

Sato

Watanabe

et al. 2006

Polym J

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ABSTRACT:Dynamic viscoeasticity of poly(vinyl alcohol) with high isotacticity (HI-PVA, mm ¼ 0:78), being derived from tert-butyl vinyl ether, was investigated to compare with that of syndiotactc PVA (S-PVA, mm ¼ 0:14) and commercial atactic PVA (A-PVA, mm ¼ 0:22). In the non-crystalline region, the a (local twisting motion) and a (micro-Brownian motion) dispersions occurring at around À10 C and 70 C were nearly the same, in both magnitude and location, for the HI-PVA and S-PVA having an almost identical degree of crystallinity. On the other hand, in the crystalline region, the c and c dispersions of HI-PVA were somewhat different from those of ordinary PVAs. The c dispersion (local motion in crystals due to defects) was clearly observed for HI-PVA but not for S-PVA and A-PVA. The c dispersion (axial motion of the chain in the crystal lattices) was observed for all PVA films but its temperature increased in the order of HI-PVA > S-PVA > A-PVA, which well corresponded to the order of the melting temperature and 13 C spin-lattice relaxation time (T 1C ) of each stereoregular PVA. These differences may be attributed to a difference of the magnitude of intermolecular and/or intramolecular hydrogen bonding in the crystals of respective PVAs. Specifically, the successive intramolecular bonding in the HI-PVA crystal appears to reduce the magnitude of the intermolecular bonding thereby allowing the chain to exhibit the c motion. This successive bonding would also stiffen the chain backbone thereby increasing the c dispersion temperature. [doi:10.1295/polymj.PJ2005235] KEY WORDS Highly Isotactic Poly(vinyl alcohol) / Stereoregular Polymerization / Viscoelasticity / Many efforts have been made for synthesis of stereoregular poly(vinyl alcohol)s (PVAs) being rich in syndiotactic or isotactic sequences 1-3 and changes of their physical properties with the stereoregularity, possibly reflecting changes in the inter-and intramolecular hydrogen bonding, have been extensively investigated. A series of radical-polymerized poly(vinyl ester)s was utilized to synthesize syndiotactic PVAs, and the relationships between stereoregularity and physical properties of PVA have been examined. 1-3Isotactic PVAs were synthesized successfully from poly(vinyl ether)s such as poly(benzyl vinyl ether) (PBzVE), 4,5 poly(tert-butyl vinyl ether) (PtBVE), 6,7 and poly(trimethyl silyl vinyl ether) (PVOSi), 8,9 and their physical properties were also investigated. 1,3Despite the above efforts, the stereoregularity still remained at a low level of the mm fraction (¼ 0:70) even for so-called isotactic PVA (LI-PVA) derived from PVOSi.9,10 Recently, we studied the cationic polymerization of tBVE with boron trifluoride diethyl etherate (BF 3 . OEt 2 ) and successfully prepared the PVAs having the highest isotacticity so far reported. [10][11][12] We found interesting features of these highly isotactic PVAs (HI-PVAs) being different from those of LI-PVA and ordinary atactic PVA (A-PVA). 10,13,14 In particular, we compared the melting temperature T m , degree...

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Stereoregulation in cationic polymerization by designed Lewis acids. II. Effects of alkyl vinyl ether structure

Ouchi

Kamigaito

Sawamoto

2001

J. Polym. Sci. A Polym. Chem.

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Stereoregulation in the cationic polymerization of various alkyl vinyl ethers was investigated with bis[(2,6‐diisopropyl)phenoxy]titanium dichloride (1; catalyst) in conjunction with the HCl adduct of isobutyl vinyl ether as an initiator in n‐hexane at −78 °C. The tacticities depended on the substituents of the monomers. Isobutyl and isopropyl vinyl ethers gave highly isotactic polymers (mm = 83%), whereas tert‐butyl and n‐butyl vinyl ethers resulted in lower isotactic contents (mm ∼ 50%) similar to those for TiCl4, a conventional Lewis acid, thus indicating that the steric bulkiness of the substituents was not the critical factor in stereoregulation. A statistical analysis revealed that the high isospecificity was achieved not by the chain end but by the catalyst 1 or the counteranion derived therefrom. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1060–1066, 2001

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Preparation of highly isotactic poly(vinyl alcohol)

Cited by 44 publications

References 1 publication

Biodegradation of Poly(vinyl alcohol) with High Isotacticity

Biodegradation of Poly(vinyl alcohol) with High Isotacticity

Highly Isotactic Poly(vinyl alcohol) Derived from tert-Butyl Vinyl Ether V. Viscoelastic Behavior of Highly Isotactic Poly(vinyl alcohol) Films

Stereoregulation in cationic polymerization by designed Lewis acids. II. Effects of alkyl vinyl ether structure

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