Hydrophobic materials based on cotton linter cellulose and an epoxy-activated polyester derived from a suberin monomer

Holzforschung ◽  
2015 ◽  
Vol 69 (6) ◽  
pp. 721-730 ◽  
Author(s):  
Dongfang Li ◽  
Tommy Iversen ◽  
Monica Ek
Keyword(s):  
Water Repellency ◽  
Magic Angle Spinning ◽  
Size Exclusion ◽  
Birch Bark ◽  
Magic Angle ◽  
Scanning Calorimetry ◽  
Outer Bark ◽  
Water Contact ◽  
Flight Mass Spectrometry ◽  
Hydrophobic Materials

Abstract Suberin is a natural hydrophobic material that could be used to improve the water repellency of cellulose surfaces. It is also abundant in the outer bark of birch (Betula verrucosa); birch bark is a side-stream product in Scandinavia from the forest industry, which is generally burned for energy production. A suberin monomer, cis-9,10-epoxy-18-hydroxyoctadecanoic acid, was isolated from birch outer bark and polymerized via lipase (immobilized Candida antarctica lipase B). The resulting epoxy-activated polyester was characterized by nuclear magnetic resonance (NMR) imaging, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry, and size exclusion chromatography. Then the polyester was cured with tartaric or oxalic acid, and the crosslinked polyesters were characterized by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry. Hydrophobic materials were prepared by compression molding of polyester-impregnated cellulose sheets, and the final products were characterized by FTIR, cross-polarization magic angle spinning 13C NMR, and field-emission scanning electron microscopy. The water contact angle was significantly increased from 0° for the original cellulose sheets to over 100° for the produced hydrophobic materials.

scholarly journals Towards Novel Fluorinated Methacrylic Coatings for Cultural Heritage: A Combined Polymers and Surfaces Chemistry Study

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1190 ◽  
Author(s):  
Valentina Sabatini ◽  
Eleonora Pargoletti ◽  
Valeria Comite ◽  
Marco Aldo Ortenzi ◽  
Paola Fermo ◽  
...  
Keyword(s):  
Prolonged Exposure ◽  
Accelerated Aging ◽  
Water Repellency ◽  
Size Exclusion ◽  
Butyl Methacrylate ◽  
Capillary Absorption ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Coated Materials ◽  
Exclusion Chromatography

In this work, new co- and ter-polymers of methyl methacrylate (MMA), ethyl methacrylate (EMA), and N-butyl methacrylate (nBuMA), containing just 1% mol × mol−1 of a fluorinated co-monomer, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octyl methacrylate (POMA), were synthesized. After an UV accelerated aging test, the photo-chemical stability of the polymers prepared was determined by 1H NMR and FT-IR spectroscopy, size exclusion chromatography, differential scanning calorimetry and wettability measurements. The polymers were applied to Botticino tiles to achieve better performances in terms of water repellency and consequently deterioration resistance. One-year prolonged exposure to a real environment was conducted and the properties of the coated materials and their performances were studied using different surface techniques such as water contact angle (WCA) and colorimetric measurements (CIELaB), capillary absorption, permeability (RVP) tests and soluble salts determination. The effectiveness of the fluorinated methacrylic coatings was clearly demonstrated; among all the resins, the co-polymer MMA_POMA seems to be the most performing one. Furthermore, both the UV photo-chemical resistance and the easiness of removal was successfully studied.

scholarly journals Physicochemical properties and structural dynamics of organic–inorganic hybrid [NH3(CH2)3NH3]ZnX4 (X = Cl and Br) crystals

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ae Ran Lim ◽  
Sun Ha Kim ◽  
Yong Lak Joo
Keyword(s):  
Structural Dynamics ◽  
Chemical Shifts ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Scanning Calorimetry ◽  
Inorganic Hybrid ◽  
Halogen Atoms

AbstractThe physical properties of the organic–inorganic hybrid crystals having the formula [NH3(CH2)3NH3]ZnX4 (X = Cl, Br) were investigated. The phase transition temperatures (TC; 268K for Cl and 272K for Br) of the two crystals bearing different halogen atoms in their skeletons were determined through differential scanning calorimetry. The thermodynamic properties of the two crystals were investigated through thermogravimetric analysis. The structural dynamics, particularly the role of the [NH3(CH2)3NH3] cation, were probed through 1H and 13C magic-angle spinning nuclear magnetic resonance spectroscopy as a function of temperature. The 1H and 13C NMR chemical shifts did not show any changes near TC. In addition, the 1H spin–lattice relaxation time (T1ρ) varied with temperature, whereas the 13C T1ρ values remained nearly constant at different temperatures. The T1ρ values of the atoms in [NH3(CH2)3NH3]ZnCl4 were higher than those in [NH3(CH2)3NH3]ZnBr4. The observed differences in the structural dynamics obtained from the chemical shifts and T1ρ values of the two compounds can be attributed to the differences in the bond lengths and halogen atoms. These findings can provide important insights or potential applications of these crystals.

scholarly journals Development and Evaluation of Matrices Composed of β-cyclodextrin and Biodegradable Polyesters in the Controlled Delivery of Pindolol

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 500
Author(s):  
Agnieszka Lis-Cieplak ◽  
Filip Charuk ◽  
Marcin Sobczak ◽  
Anna Zgadzaj ◽  
Agata Drobniewska ◽  
...  
Keyword(s):  
Heart Diseases ◽  
Coupling Reaction ◽  
Magic Angle Spinning ◽  
Burst Release ◽  
Magic Angle ◽  
Chemical Structures ◽  
Drug Conjugates ◽  
Flight Mass Spectrometry ◽  
Angle Spinning

Polymer-drug conjugates are currently being more widely investigated for the treatment of hypertension. In view of the above, in the first stage of our work, we used nontoxic β-cyclodextrin (β-CD) as effective, simple, inexpensive, and safe for the human body initiator for the synthesis of biocompatible and biodegradable functionalized polymers suitable for the medical and pharmaceutical applications. The obtained polymeric products were synthesized through a ring-opening polymerization (ROP) of ε-caprolactone (CL), d,l-, and l,l-lactide (LA and LLA). The chemical structures of synthesized materials were elucidated based on 1H NMR and solid-state carbon-13 cross-polarization/magic angle spinning nuclear magnetic resonance (13C CP/MAS NMR) analysis, while the incorporation of β-CD molecule into the polymer chain was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Furthermore, molecular modeling has been applied to investigate the intrachain rigidities and chain architectures for several representative structures. The obtained and thoroughly characterized branched matrices were then used to generate the first β-cyclodextrin/biodegradable polymer/β-blocker conjugate through the successful conjugation of pindolol. The conjugates were fabricated by carbodiimide-mediated coupling reaction. The branched biodegradable materials released the drug in vitro in a sustained manner and without “burst release” and thus have the ability to treat different heart diseases.

Synthesis of a lignin polymer model consisting of only phenolic β-O-4 linkages and testing its reactivity under alkaline conditions 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Jackson D. Megiatto ◽  
Emmanuel Cazeils ◽  
Stéphane Grelier ◽  
Christian Gardrat ◽  
Frédérique Ham-Pichavant ◽  
...  
Keyword(s):  
Chemical Reactivity ◽  
Bond Cleavage ◽  
Degree Of Polymerization ◽  
Size Exclusion ◽  
Quinone Methide ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Maldi Tof ◽  
Flight Mass Spectrometry ◽  
Alkaline Conditions

Abstract A trimeric β-O-4 lignin model bearing a styrene unit was polymerized in the presence of azobisisobutyronitrile as an initiator of free radical polymerization. The polymer analysis achieved by size exclusion chromatography (SEC), 1H, 13C, 31P NMR, matrix-assisted laser desorption ionization combined with time-of-flight mass spectrometry (MALDI-ToF MS), differential scanning calorimetry, and thermogravimetry indicated its well-defined structure with good thermal stability at temperatures usually applied for alkaline pulping. SEC analysis proved a high degree of polymerization despite the size of the phenolic β-O-4 units in the polymer structure. MALDI-ToF spectrometry indicated that the polymer is composed of phenolic β-O-4 elements only. The chemical reactivity under alkaline conditions of the polymer was studied by both HPLC and 31P NMR. These two methods revealed two main concurrent processes, which include an oxidation of the phenol part followed by Cα-Cβ bond cleavage, and a formation of a quinone methide followed by its β-O-4 bond cleavage.

Synthesis and characterization of new inorganic polymeric composites based on kaolin or white clay and on ground-granulated blast furnace slag

2003 ◽  
Vol 18 (11) ◽  
pp. 2571-2579 ◽  
Author(s):  
I. Lecomte ◽  
M. Liégeois ◽  
A. Rulmont ◽  
R. Cloots ◽  
F. Maseri
Keyword(s):  
Blast Furnace ◽  
Vickers Hardness ◽  
Blast Furnace Slag ◽  
Polymeric Materials ◽  
Magic Angle Spinning ◽  
Alkali Activation ◽  
Magic Angle ◽  
Scanning Calorimetry ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

Alkali activation of dehydroxylated kaolin or clay yielded high-strength polymeric materials, so-called geopolymers. They were synthesized by mixing the aluminosilicate with solutions of sodium metasilicate and KOH followed by adding 45 wt.% of ground-granulated blast furnace slag. The influence of the aluminosilicate source, its activation temperature, and the order of mixing raw materials were studied on the workability of the blending paste, the microstructure, and the Vickers hardness of the geopolymer samples. The polymeric material is completely amorphous according to x-ray diffraction. Solid-state 27Al and 29Si magic-angle-spinning nuclear magnetic resonance showed that the geopolymer consists of AlO4 and SiO4 tetrahedra linked together through a polymeric network constituted by branched entities SiQ4(4Al) and SiQ4(3Al), but also by less-polymerized silicates SiQ1 and SiQ2. Scanning electron microscopy showed a homogeneous polymeric gel matrix containing unreacted slag (and quartz) grains; thermogravimetric analysis and differential scanning calorimetry exhibited a high content of water and an elevated melting point (1260°C). Vickers hardness values are in the range of 200 MPa.

scholarly journals Preparation, Thermal, and Physical Properties of Perovskite-Type (C3H7NH3)2CdCl4 Crystals

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 108 ◽  
Author(s):  
Ae Lim ◽  
Sun Kim
Keyword(s):  
Phase Transitions ◽  
Physical Properties ◽  
Relaxation Times ◽  
Magic Angle Spinning ◽  
Mas Nmr ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Scanning Calorimetry ◽  
Two Phase ◽  
Perovskite Type

To investigate the thermal and physical properties of perovskite-type (C3H7NH3)2CdCl4, its temperature-dependent chemical shifts and spin–lattice relaxation times are measured using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), magic angle spinning nuclear magnetic resonance (MAS NMR), and static NMR methods. Above 300 K, two phase transitions are observed at 398 K and 538 K. Each proton and carbon in the (C3H7NH3) cation is distinguished in the MAS NMR results. The environments around 1H, 13C, and 14N do not change with temperature according to the NMR spectra. In contrast, the resonance frequency of 113Cd in the CdCl6 octahedra decreases with increasing temperature, indicating an environmental change. The uniaxial rotations for 1H and 13C have high mobility at both high and low temperatures, and these are related to the phase transitions. In addition, the molecular motion of 113Cd in the anion becomes activated upon raising the temperature.

scholarly journals Effect of the Sulfonation on the Swollen State Morphology of Styrenic Cross-Linked Polymers

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 600 ◽  
Author(s):  
Chiara Dalla Valle ◽  
Marco Zecca ◽  
Federico Rastrelli ◽  
Cristina Tubaro ◽  
Paolo Centomo
Keyword(s):  
Solid State ◽  
Elemental Analysis ◽  
Solid State Nmr ◽  
Chlorosulfonic Acid ◽  
Magic Angle Spinning ◽  
Exchange Capacity ◽  
Size Exclusion ◽  
Magic Angle ◽  
Ft Ir ◽  
Polymer Fraction

The chemical structure and morphology of a set of sulfonic gel-type poly(styrene-divinylbenzene) resins (2 mol% DVB) prepared with different synthetic approaches were investigated by solid state NMR, Inverse Size Exclusion Chromatography (ISEC), FT-IR and elemental analysis to compare their swollen state structure. FT-IR and solid state NMR clearly show that the sulfonation mainly occurs in the para- position with respect the main polymer chain. Sensible proportions of sulfone bridges were found in the materials obtained with oleum and chlorosulfonic acid. With oleum, the presence of the sulfone bridges is clearly associated to a reduced ability to swell in the water medium relative to the proton exchange capacity. This highlights the cross-linking action of the sulfone bridges according to ISEC results, showing a high proportion of a dense polymer fraction in the swollen material. An even higher degree of sulfone-bridging, lower swelling ability, and a high proportion of a dense polymer fraction in the swollen material are found in the resin obtained with chlorosulfonic acid. As a matter of fact, Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance (CP-MAS 13C-NMR), elemental analysis, and ion exchange capacity, show that oleum and chlorosulfonic acid produced resins with remarkably smaller pores and lower swollen gel volume in polar solvents, with respect to concentrated sulfuric acid.

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