Synthetic Poly[(R,S)-.beta.-hydroxyalkanoates] with Butyl and Hexyl Side Chains

Jesudason, J. J.; Marchessault, R. H.

doi:10.1021/ma00087a031

Cited by 10 publications

(5 citation statements)

References 5 publications

(9 reference statements)

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“…Crystalline peaks and characteristic reflections found in the literature were used to determine the degree of crystallinity: 11.47 ° (040), 17.94 ° (120), 18.71 ° (130), 19.32 ° (011), 20.45 ° (140), 21.66 ° (031), 22.84 ° (080), 28.78 (200).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Structural, topographical, and mechanical characteristics of purified polyhydroxyoctanoate polymer

Sofińska

Barbasz

Witko

et al. 2018

J of Applied Polymer Sci

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Insight into the topographic and mechanical properties of biomaterials allows for efficient selection of a material for a specific application. Here, atomic force microscopy (AFM) and force spectroscopy were exploited to reveal the topographic and mechanical characteristics of charcoal‐purified, solvent‐cast polyhydroxyoctanoate (PHO) film. The root mean square surface roughness of a PHO surface derived from ethyl acetate, acetone, or chloroform solution was 13.2, 11.5, or 30.9 nm, respectively, for 100 μm2 AFM images. The distribution of the local Young's modulus had a maximum of 25.4, 14.1, and 12.6 MPa for PHO films obtained from ethyl acetate, acetone, and chloroform solution, respectively. The positron annihilation spectroscopy measurements allowed us to determine the free volume in the polymer film structure (9.38%). Moreover, a number of additional techniques (X‐ray diffraction, thermogravimetric analysis, differential scanning calorimetry, gel permeation chromatography, NMR, infrared spectroscopy, and polarized light microscopy) were used to reveal PHO features. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47192.

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Section: Methodsmentioning

confidence: 99%

“…Crystalline peaks and characteristic reflections found in the literature 35 TGA was performed on a Netzsch STA 409 PC Luxx (Selb, Germany). A sample of about 7 mg was placed in an aluminum oxide crucible and heated in nitrogen atmosphere at a rate of 10 C/min from room temperature to 700 C.…”

Section: Pho Monomer Composition Determination and Purity By Nmr Specmentioning

confidence: 99%

Structural, topographical, and mechanical characteristics of purified polyhydroxyoctanoate polymer

Sofińska

Barbasz

Witko

et al. 2018

J of Applied Polymer Sci

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“…Coordination initiators have also been widely used. Actually, a series of poly(β-PL) was prepared from the ring-opening polymerization of the corresponding racemic β-PL by means of stereoselective organoaluminum or organozinc catalysts. − It is generally found that racemic monomers lead to atactic polymers, , although some initiators promote the formation of an isotactic small fraction. − ,, Similar results were obtained with aluminoxane catalysts, −(AlR−O) n −, although these catalysts are believed to be more stereoregulating and have better catalytic activity than the trialkylaluminum/water system. − Recently, Jesudason and Marchessault reported the synthesis of highly isotactic poly(β-hydroxyheptanoate) and poly(β-hydroxynonanoate) by polymerization of the corresponding racemic monomers, using a trimethylaluminum/water catalyst, but the yields obtained were of the order of 5 and 2%, respectively. The use of tin-based catalysts has been finally investigated − and a predominantly syndiotactic poly(CH 3 -PL), eventually after fractionation, was obtained from the polymerization of racemic CH 3 -PL.…”

Section: Introductionmentioning

confidence: 86%

“…[13][14][15][16]21,22 Similar results were obtained with aluminoxane catalysts, -(AlR-O) n -, although these catalysts are believed to be more stereoregulating and have better catalytic activity than the trialkylaluminum/water system. [23][24][25][26] Recently, Jesudason and Marchessault 27 reported the synthesis of highly isotactic poly(β-hydroxyheptanoate) and poly(βhydroxynonanoate) by polymerization of the corresponding racemic monomers, using a trimethylaluminum/ water catalyst, but the yields obtained were of the order of 5 and 2%, respectively. The use of tin-based catalysts has been finally investigated [28][29][30][31] and a predominantly syndiotactic poly(CH 3 -PL), eventually after fractionation, was obtained from the polymerization of racemic CH 3 -PL.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Racemic and Isotactic Poly(β-alkyl-β-propiolactone)s

Brochu

Prud’homme

1998

Macromolecules

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Isotactic poly(β-methyl-β-propiolactone) (poly(CH3-PL)) and poly(β-ethyl-β-propiolactone) (poly(C2H5-PL)) with (S) and (R) configurations, respectively, were synthesized in yields of 70% via the polymerization of optically active β-(trichloromethyl)-β-propiolactone (CCl3-PL) and β-(dichloroethyl)-β-propiolactone (CH3CCl2-PL). The polymerization was conducted in bulk, under vacuum, using the triethylaluminum/water or the diethylzinc/water catalysts. These polymerizations were followed by the dechlorination of the resulting chlorinated polymers, using the tri-n-butyltin hydride (Bu3SnH) reducing agent. 13C NMR spectroscopy shows that all the chlorinated and dechlorinated polymers have a degree of isotacticity of 100%, indicating that little or no racemization occurs during the course of the polymerization. Atactic homologues were also synthesized; these are soluble in the usual organic solvents, contrary to the isotactic polymers. Multiangle laser light scattering analyses of atactic polymers indicate that the dechlorination reaction occurs with some degradation, leading to poly(CCl3-PL) and poly(CH3CCl2-PL) with molecular weights of about 5000. The variations of the glass transition temperature, melting temperature, and enthalpy of fusion with the dechlorination ratio are discussed. The whole analysis shows that the dechlorination reaction generates statistical copolymers, with the formation of the intermediate homopolymers poly(CHCl2-PL) and poly(CH2Cl-PL) in the case of the dechlorination of poly(CCl3-PL). X-ray patterns show that each homopolymer has its own crystalline structure and that the semicrystalline copolymers adopt a crystalline structure similar to that of the homopolymer of closest composition.

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“…has shown that distannoxane catalysts can polymerize BL in 4 h reaction times at 100 °C to form products in yields of >95% having M n values of approximately 150 000. Much effort has also been focused on the use of Al- and Zn-based catalyst systems for the preparation of synthetic PHA analogues . In parallel with the above, research has been carried out to prepare enantioenriched BL.…”

Section: Introductionmentioning

confidence: 99%

Chemoenzymatic Route to Poly(3-hydroxybutyrate) Stereoisomers

Gross

Kaplan

et al. 1996

Macromolecules

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Racemic butyrolactone (BL) was selected to determine the feasibility of using enzyme catalysis in organic media for β-substituted β-propiolactone resolutions. Lipases from Candida cylindracia, Pseudomonas fluorescens (PS-30), and porcine pancreatic lipase Type II (PPL) were investigated. Based on reaction rate and the enantiomeric ratio E, PPL was found to be the most effective of these lipases. With respect to the organic media used, BL methanolysis occurred faster to slower as follows: n-hexane > diethyl ether > dioxane ≅ ethyl acetate > benzene. PPL-catalyzed BL methanolysis in n-hexane and diethyl ether reached ∼50% conversion in 22 h. Irrespective of the solvent used, the slower reacting enantiomer was (R)-BL. The E values for PPL-catalyzed BL resolutions carried out in diethyl ether, benzene, ethyl acetate, 1,4-dioxane, and hexane were 20.4 ± 2.4, 14.8 ± 2.3, 8.94 ± 1.28, 8.15 ± 1.04, and 5.56 ± 0.37, respectively. Thus, using PPL as the lipase in ether, 90%-(R)-BL was obtained in 35% yield. This monomer was polymerized using Zn(C2H5)2/H2O (1/0.6) as the catalyst to form predominantly (R)-poly(3-hydroxybutyrate) (P3HB) which had number-average molecular weight, melting point, and enthalpy of melting values of 41 300, 140 °C, and 64.6 J/g, respectively. Thus, a chemoenzymatic route to high molecular weight enantiomerically enriched P3HB was demonstrated.

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Synthetic Poly[(R,S)-.beta.-hydroxyalkanoates] with Butyl and Hexyl Side Chains

Cited by 10 publications

References 5 publications

Structural, topographical, and mechanical characteristics of purified polyhydroxyoctanoate polymer

Structural, topographical, and mechanical characteristics of purified polyhydroxyoctanoate polymer

Synthesis and Characterization of Racemic and Isotactic Poly(β-alkyl-β-propiolactone)s

Chemoenzymatic Route to Poly(3-hydroxybutyrate) Stereoisomers

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