Characterization of impact-resistant poly(propylene–ethylene) copolymers by 13C nuclear magnetic resonance spectroscopy, temperature-rising elution fractionation–size exclusion chromatography, and transmission electron microscopy

1993 ◽  
Vol 52 (0) ◽  
pp. 145-158 ◽  
Author(s):  
Takao Usami ◽  
Yukitaka Gotoh ◽  
Hisao Umemoto ◽  
Shigeru Takayama
Keyword(s):  
Electron Microscopy ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Ethylene Copolymers ◽  
Temperature Rising Elution Fractionation ◽  
Transmission Electron ◽  
13C Nuclear Magnetic Resonance ◽  
Exclusion Chromatography ◽  
Poly Propylene

Structure of a shear-thickening polysaccharide extracted from the New Zealand black tree fern, Cyathea medullaris

2020 ◽  
Author(s):  
M Wee ◽  
M Mastrangelo ◽  
Susan Carnachan ◽  
Ian Sims ◽  
K Goh
Keyword(s):  
New Zealand ◽  
Uronic Acid ◽  
Average Molecular Weight ◽  
Shear Thickening ◽  
Water Soluble ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Tree Fern ◽  
13C Nuclear Magnetic Resonance ◽  
Exclusion Chromatography

A shear-thickening water-soluble polysaccharide was purified from mucilage extracted from the fronds of the New Zealand black tree fern (Cyathea medullaris or 'mamaku' in Māori) and its structure characterised. Constituent sugar analysis by three complementary methods, combined with linkage analysis (of carboxyl reduced samples) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR) revealed a glucuronomannan comprising a backbone of 4-linked methylesterified glucopyranosyl uronic acid and 2-linked mannopyranosyl residues, branched at O-3 of 45% and at both O-3 and O-4 of 53% of the mannopyranosyl residues with side chains likely comprising terminal xylopyranosyl, terminal galactopyranosyl, non-methylesterified terminal glucopyranosyl uronic acid and 3-linked glucopyranosyl uronic acid residues. The weight-average molecular weight of the purified polysaccharide was ~1.9×106Da as determined by size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS). The distinctive rheological properties of this polysaccharide are discussed in relation to its structure. © 2014 Elsevier B.V.

Structure of a shear-thickening polysaccharide extracted from the New Zealand black tree fern, Cyathea medullaris

2020 ◽  
Author(s):  
M Wee ◽  
M Mastrangelo ◽  
Susan Carnachan ◽  
Ian Sims ◽  
K Goh
Keyword(s):  
New Zealand ◽  
Uronic Acid ◽  
Average Molecular Weight ◽  
Shear Thickening ◽  
Water Soluble ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Tree Fern ◽  
13C Nuclear Magnetic Resonance ◽  
Exclusion Chromatography

A shear-thickening water-soluble polysaccharide was purified from mucilage extracted from the fronds of the New Zealand black tree fern (Cyathea medullaris or 'mamaku' in Māori) and its structure characterised. Constituent sugar analysis by three complementary methods, combined with linkage analysis (of carboxyl reduced samples) and 1H and 13C nuclear magnetic resonance spectroscopy (NMR) revealed a glucuronomannan comprising a backbone of 4-linked methylesterified glucopyranosyl uronic acid and 2-linked mannopyranosyl residues, branched at O-3 of 45% and at both O-3 and O-4 of 53% of the mannopyranosyl residues with side chains likely comprising terminal xylopyranosyl, terminal galactopyranosyl, non-methylesterified terminal glucopyranosyl uronic acid and 3-linked glucopyranosyl uronic acid residues. The weight-average molecular weight of the purified polysaccharide was ~1.9×106Da as determined by size-exclusion chromatography coupled with multi-angle laser light scattering (SEC-MALLS). The distinctive rheological properties of this polysaccharide are discussed in relation to its structure. © 2014 Elsevier B.V.

scholarly journals Synthesis and characterization of amphiphilic graft copolymers of poly(1,3 dioxolane) macromonomers with styrene and methyl methacrylate

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Hayet Bendaikha ◽  
Gérald Clisson ◽  
Abdelouahad Khoukh ◽  
Jeanne François ◽  
Seghier Ould Kada
Keyword(s):  
Methyl Methacrylate ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Molecular Weights ◽  
Molar Ratios ◽  
H Nmr ◽  
Amphiphilic Graft Copolymers ◽  
Exclusion Chromatography ◽  
Cationic Ring Opening Polymerization

AbstractMethacrylate-terminated Poly(1,3 dioxolane) (PDXL) macromonomers were synthesized by cationic ring-opening polymerization in the presence of 2- hydroxypropyl methacrylate (2-HPMA) as transfer agent. Molecular weights, polydispersity index and functionality of the PDXL macromonomers were evaluated by size exclusion chromatography (SEC) and 1H nuclear magnetic resonance spectroscopy (1H-NMR). Copolymerizations of PDXL macromonomers, of different molecular weights, with styrene (St) and methyl methacrylate (MMA) were carried out using various feed molar ratios. The resulting polymers confirmed the grafting of PDXL with PS and PMMA by SEC and 1H-NMR Monomer reactivity ratios between the macromonomers and the comonomers were estimated from the copolymerization results. Macromonomer reactivity depends on the comonomer considered. Glass transition temperatures of the copolymers were found to decrease with an increase in the amount of PDXL in the copolymers. The values of Tg depend on the composition and the size of the PDXL grafts.

Dispersion and improvement of organoclays in nanocomposites based on poly(propylene oxide)

2020 ◽  
pp. 089270572093917 ◽  
Author(s):  
Lahouari Mrah ◽  
Rachid Meghabar
Keyword(s):  
Electron Microscopy ◽  
Propylene Oxide ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
The Matrix ◽  
Organic Clay ◽  
Poly Propylene

This work is mainly concentrated on the preparation and characterization of poly(propylene oxide) (PPO)/organic clay nanocomposites. The effects of the nature of organoclays and the method of preparation have been elucidated to evaluate their morphological, structural and thermal properties. These nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermal analysis (differential scanning calorimetry) and thermogravimetric analysis (TGA). This study involved the use of an Algerian clay called ‘maghnite’ which was modified by an incorporation method using different concentrations of the surfactant cetyltrimethylammonium bromide (CTAB). Propylene oxide (PO) was polymerized in the presence of ethylene glycol and various proportions of organic clay ranging from 1%, 5% and 10% by weight. The structural study by XRD showed, at different loading rates of maghnite and PO in the preparation of PPO/maghnite nanocomposites, different morphologies: intercalated/exfoliated blend and intercalated/agglomerated. TGA showed that the intercalation of PPO at the montmorillonite (MMT)-CTA interface would be more advantageous since the required amount of 5% organic clay (by weight) ensures high thermal stability of the nanocomposites, and the glass transition temperature ( T g) of PPO/MMT nanocomposites is higher than that of PPO since this increase is due to the introduction of clay into the matrix which makes the nanocomposite more rigid.

The structure of the extracellular teichoic acids from the allergy-protective bacterium Lactococcus lactis G121

2012 ◽  
Vol 393 (8) ◽  
pp. 749-755
Author(s):  
Kathleen Fischer ◽  
Evgueny Vinogradov ◽  
Buko Lindner ◽  
Holger Heine ◽  
Otto Holst
Keyword(s):  
Lactococcus Lactis ◽  
Molecular Mechanisms ◽  
Cell Envelope ◽  
Teichoic Acid ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
Protective Properties ◽  
Isolation And Characterization ◽  
Exclusion Chromatography

Abstract The Gram-positive bacterium Lactococcus lactis G121 is a farm isolate that protects mice from ovalbumin-induced asthma. To understand the molecular mechanisms of such allergy-protective properties, the isolation and characterization of cell envelope constituents is crucial. Here, structural analyses of the extracellular teichoic acid (EC TA) from L. lactis G121 are presented. Extraction with 0.9% saline afforded a crude TA fraction. Consecutive size exclusion chromatography on Biogel P60 and P10 matrix was performed to purify the sample. Chemical component analyses, high-resolution electrospray ionization Fourier-transformed ion cyclotron mass spectrometry, and nuclear magnetic resonance spectroscopy were conducted for structural elucidation. The EC TA was a poly(glycosylglycerol phosphate) molecule with a repeating unit of -6)-[β-d-Glcp-(1→3)-][α-d-GlcpNAc-(1→4)-]α-d-GalpNAc-(1→3)-β-d-GlcpNAc-(1→2)-glycerol-(1-P-).

Toscana virusnucleoprotein oligomer organization observed in solution

2017 ◽  
Vol 73 (8) ◽  
pp. 650-659 ◽  
Author(s):  
Amal Baklouti ◽  
Adeline Goulet ◽  
Julie Lichière ◽  
Bruno Canard ◽  
Rémi N. Charrel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Size Exclusion ◽  
Integrative Approach ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Closed Ring ◽  
Rnp Complex ◽  
Exclusion Chromatography ◽  
Nucleoprotein N

Toscana virus(TOSV) is an arthropod-borne virus belonging to thePhlebovirusgenus within theBunyaviridaefamily. As in other bunyaviruses, the genome of TOSV is made up of three RNA segments. They are encapsidated by the nucleoprotein (N), which also plays an essential role in virus replication. To date, crystallographic structures of phlebovirus N have systematically revealed closed-ring organizations which do not fully match the filamentous organization of the ribonucleoprotein (RNP) complex observed by electron microscopy. In order to further bridge the gap between crystallographic data on N and observations of the RNP by electron microscopy, the structural organization of recombinant TOSV N was investigated by an integrative approach combining X-ray diffraction crystallography, transmission electron microscopy, small-angle X-ray scattering, size-exclusion chromatography and multi-angle laser light scattering. It was found that in solution TOSV N forms open oligomers consistent with the encapsidation mechanism of phlebovirus RNA.

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