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.

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.

A study on the kinetics and thermal properties of polystyrene/diatomite nanocomposites prepared via in situ ATRP

2018 ◽  
Vol 33 (2) ◽  
pp. 180-197 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
In Situ Polymerization ◽  
Structural Characteristics ◽  
Nitrogen Adsorption ◽  
Linear Increase ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography

Pristine mesoporous diatomite was employed to prepare polystyrene/diatomite composites. Diatomite platelets were used for in situ polymerization of styrene by atom transfer radical polymerization to synthesize tailor-made polystyrene nanocomposites. X-Ray fluorescence spectrometer analysis and thermogravimetric analysis (TGA) were employed for evaluating some inherent properties of pristine diatomite platelets. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the diatomite platelets. Evaluation of pore size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography, respectively. Linear increase of ln ( M0/M) with time for all the samples shows that polymerization proceeds in a living manner. Addition of 3 wt% pristine mesoporous diatomite leads to an increase of conversion from 72% to 89%. Molecular weight of polystyrene chains increases from 11,326 g mol−1 to 14134 g mol−1 with the addition of 3 wt% pristine mesoporous diatomite; however, polydispersity index values increases from 1.13 to 1.38. Increasing thermal stability of the nanocomposites is demonstrated by TGA. Differential scanning calorimetry shows an increase in glass transition temperature from 81.9°C to 87.1°C by adding 3 wt% of mesoporous diatomite platelets.

scholarly journals The influence of hydrogen bonding on radical chain-growth parameters for butyl methacrylate/2-hydroxyethyl acrylate solution copolymerization

2016 ◽  
Vol 7 (27) ◽  
pp. 4567-4574 ◽  
Author(s):  
Jan E. S. Schier ◽  
Robin A. Hutchinson
Keyword(s):  
Growth Parameters ◽  
Propagation Rate ◽  
Size Exclusion ◽  
Rate Coefficients ◽  
Butyl Methacrylate ◽  
Chain Growth ◽  
Copolymer Composition ◽  
Radical Chain ◽  
Effect Of Solvent ◽  
Exclusion Chromatography

Pulsed laser polymerizations coupled with size exclusion chromatography (PLP-SEC) and NMR analyses were performed to determine radical kinetic parameters for BMA/HEA, with a focus on the effect of solvent choice and H-bonding on both copolymer composition and copolymer-averaged propagation rate coefficients.

scholarly journals Solvent Effects on Radical Copolymerization Kinetics of 2-Hydroxyethyl Methacrylate and Butyl Methacrylate

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 487 ◽  
Author(s):  
Loretta Idowu ◽  
Robin Hutchinson
Keyword(s):  
Monomer Concentration ◽  
Propagation Rate ◽  
Radical Copolymerization ◽  
Size Exclusion ◽  
Butyl Methacrylate ◽  
Copolymer Composition ◽  
Solvent Mixtures ◽  
Hydroxyethyl Methacrylate ◽  
Kinetic Coefficients ◽  
Exclusion Chromatography

2-Hydroxyethyl methacrylate (HEMA) is an important component of many acrylic resins used in coatings formulations, as the functionality ensures that the chains participate in the cross-linking reactions required to form the final product. Hence, the knowledge of their radical copolymerization kinetic coefficients is vital for both process and recipe improvements. The pulsed laser polymerization (PLP) technique is paired with size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR) to provide kinetic coefficients for the copolymerization of HEMA with butyl methacrylate (BMA) in various solvents. The choice of solvent has a significant impact on both copolymer composition and on the composition-averaged propagation rate coefficient (kp,cop). Compared to the bulk system, both n-butanol and dimethylformamide reduce the relative reactivity of HEMA during copolymerization, while xylene as a solvent enhances HEMA reactivity. The magnitude of the solvent effect varies with monomer concentration, as shown by a systematic study of monomer/solvent mixtures containing 50 vol%, 20 vol%, and 10 vol% monomer. The observed behavior is related to the influence of hydrogen bonding on monomer reactivity, with the experimental results fit using the terminal model of radical copolymerization to provide estimates of reactivity ratios and kp,HEMA.

Combined Main- and Side-Chain Azobenzene Polyesters: A Potential For Photoinduced Nonlinear Waveguides

1999 ◽  
Vol 561 ◽  
Author(s):  
F. Sahlén ◽  
T. Geisler ◽  
S. Hvilsted ◽  
N. C. R. Holme ◽  
P. S. Ramanujam ◽  
...  
Keyword(s):  
Refractive Index ◽  
Third Harmonic Generation ◽  
Size Exclusion ◽  
Side Chain ◽  
Visible Spectroscopy ◽  
Scanning Calorimetry ◽  
Nonlinear Waveguides ◽  
Third Harmonic ◽  
Exclusion Chromatography ◽  
Uv Visible

ABSTRACTNew combined main- and side-chain azobenzene polyesters, which exhibit an intensity dependent refractive index, have been prepared in order to optically fabricate nonlinear waveguides. Novel sulfone azobenzenes, a diester, (4-[[5-(ethoxycarbonyl)pentyl]sulfonyl]-4'-[[5-(ethoxycarbonyl)pentyl]methylamino] azobenzene, and a diol, 4-[[(8-hydroxy-7-methylhydroxy)-octyl]sulfonyl]-4'-N, N-dimethylamino azobenzene, have been used to prepare new polyesters by transesterification in the molten state. The polyesters have been characterized by UV-visible spectroscopy, differential scanning calorimetry (DSC), size exclusion chromatography (SEC), third harmonic generation (THG) and optical anisotropy measurements. The molar masses of the polyesters were in the range of 5000-10000 g mol−1, which was sufficient in order to spin coat thin films. From THG measurements the polymers are shown to possess an offresonance electronic X(3) of the order 10−12 esu corresponding to a nonlinear refractive index of 2.3×10−14 cm2/W.

scholarly journals Fluorosilane Water-Repellent Coating for the Protection of Marble, Wood and Other Materials

Heritage ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 2668-2675
Author(s):  
Fotios G. Adamopoulos ◽  
Evangelia C. Vouvoudi ◽  
Dimitris S. Achilias ◽  
Ioannis Karapanagiotis
Keyword(s):  
Polymer Networks ◽  
Treated Wood ◽  
Water Repellency ◽  
Contact Angles ◽  
Water Repellent ◽  
Capillary Absorption ◽  
Durability Test ◽  
Water Contact ◽  
Produce Water ◽  
The Aesthetic

The preservation of cultural heritage monuments and artifacts requires the development of methods to produce water-repellent materials, which can offer protection against the effects of atmospheric water. Fluorosilanes are a very promising class of materials, as they act as precursors for the formation of low surface energy polymer networks. 1H,1H,2H,2H-perfluorooctyl-triethoxysilane is applied on marble, wood and the surfaces of other materials, such as glass, silicon wafer, brass, paper and silk. According to the measurements of static water contact angles, it is reported that superhydrophobicity and enhanced hydrophobicity are achieved on the surfaces of coated marble and wood, respectively. Hydrophobicity and hydrophilicity were observed on the treated surfaces of the other materials. More important, water repellency is achieved on any hydrophobic or superhydrophobic surface, as revealed by the very low sliding angles of water drops. The study is accompanied by colorimetric measurements to evaluate the effects of the treatment on the aesthetic appearances of the investigated materials. Finally, the capillary absorption test and a durability test are applied on treated wood and marble, respectively. 

Monitoring the chemical heterogeneity of metallocenecatalysed copolymers of ethylene and higher 1-olefins using CRYSTAF and SEC-FTIR

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Sven M. Graef ◽  
Robert Brüll ◽  
Harald Pasch ◽  
Udo M. Wahner
Keyword(s):  
Differential Scanning Calorimetry ◽  
Size Exclusion Chromatography ◽  
Catalyst System ◽  
Size Exclusion ◽  
Side Chain ◽  
Chemical Heterogeneity ◽  
Scanning Calorimetry ◽  
Crystallisation Temperature ◽  
Exclusion Chromatography

Abstract Copolymers of ethylene with 1-decene, 1-tetradecene and 1-octadecene were prepared using the catalyst system racEt[Ind]2ZrCl2/MAO and were analysed with regard to chemical heterogeneity using crystallisation analysis fractionation (CRYSTAF), differential scanning calorimetry (DSC) and size exclusion chromatography coupled to FTIR (SEC-FTIR). The melting and crystallisation temperatures from DSC decrease linearly with increasing amount of comonomer, independently of the nature thereof. The decrease in crystallisation temperature from CRYSTAF of copolymers with higher 1-olefin content indicates a small dependence on the length of the side chain. The chemical heterogeneity of the copolymers as analysed by DSC and CRYSTAF broadens with increasing comonomer concentration.

INTRODUCTION OF A DOUBLE BOND CONTAINING MODIFIER ON THE SURFACE OF MCM-41 NANOPARTICLES: APPLICATION FOR SR&NI ATRP OF STYRENE

NANO ◽  
2014 ◽  
Vol 09 (02) ◽  
pp. 1450023 ◽  
Author(s):  
KHEZROLLAH KHEZRI ◽  
VAHID HADDADI-ASL ◽  
HOSSEIN ROGHANI-MAMAQANI
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
Mesoporous Silica Nanoparticles ◽  
Nitrogen Adsorption ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Morphological Studies ◽  
Exclusion Chromatography ◽  
Mcm 41

Mesoporous silica nanoparticles (MCM-41) surface was functionalized with 3-(trimethoxysilyl)propyl methacrylate (MPS). Then, the resultant double bond containing nanoparticles were used in grafting through simultaneous reverse and normal initiation technique for atom transfer radical polymerization (SR&NI ATRP) of styrene to synthesize well-defined polystyrene nanocomposites with twofold chains. Nitrogen adsorption/desorption isotherm and X-ray diffraction analysis were used to evaluate characteristics of spherical MCM-41 nanoparticles. Morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography respectively. Addition of MCM-41 nanoparticles by 3 wt.% results in a decrease of conversion from 93% to 82%. Molecular weight of the free and attached polystyrene chains decreases by adding 3 wt.% MCM-41 nanoparticles; however, PDI values increases from 1.27 to 1.78 for free chains and 1.87 to 2.48 for attached chains. A peak around 4.1 ppm which originates from hydrogen atom of terminal units of polystyrene chains in proton nuclear magnetic resonance spectra in combination with low PDI values can appropriately demonstrate the living nature of the polymerization. Increasing thermal stability of the nanocomposites is demonstrated by Thermogravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing MCM-41 nanoparticles.

NEW ELASTOMERIC MATERIALS FROM BIOMASS: STEREOSELECTIVE POLYMERIZATION OF LINEAR TERPENES AND THEIR COPOLYMERIZATION WITH BUTADIENE BY USING A COBALT COMPLEX WITH PHOSPHANE LIGANDS

2020 ◽  
Vol 93 (4) ◽  
pp. 605-614
Author(s):  
David Hermann Lamparelli ◽  
Veronica Paradiso ◽  
Carmine Capacchione
Keyword(s):  
Room Temperature ◽  
Cobalt Complex ◽  
Size Exclusion ◽  
Resonance Spectroscopy ◽  
New Materials ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Elastomeric Materials ◽  
Exclusion Chromatography ◽  
Stereoregular Polymers

ABSTRACT The polymerization of bio-renewable terpenes such as β-ocimene (O), β-myrcene (M), and β-farnesene (F) promoted by CoCl2(PCyPh2)2 (1) in combination with modified methylalumoxane at room temperature is reported. Stereoregular polymers of O, M, and F were obtained. 1 also promoted, showing good stereoselectivity, the copolymerization of O and M with butadiene (B) in a wide range of compositions by suitably varying the alimentation feed: up to 67 and 75 mol% of O and M incorporated for poly(ocimene-butadiene) and poly(myrcene-butadiene) copolymers, respectively. These new materials with elastomeric properties (glass transition temperatures observed in the range of −5.7 to −72.5 °C) were fully characterized by differential scanning calorimetry, size exclusion chromatography, and nuclear magnetic resonance spectroscopy (1H, 13C, and two-dimensional experiments).

scholarly journals The Use of Epoxy Silanes on Montmorillonite: An Effective Way to Improve Thermal and Rheological Properties of PLA/MMT Nanocomposites Obtained via “In Situ” Polymerization

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Valentina Sabatini ◽  
Hermes Farina ◽  
Luca Basilissi ◽  
Giuseppe Di Silvestro ◽  
Marco A. Ortenzi
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
In Situ Polymerization ◽  
Rheological Behaviour ◽  
Size Exclusion ◽  
Melt Crystallization ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Exclusion Chromatography

Polylactic acid (PLA) nanocomposites were prepared via “in situ” ring opening polymerization (ROP) of lactide using a montmorillonite, Cloisite 15A, employed after surface treatment with 3-Glycidoxypropyltrimethoxysilane. The dispersion of the nanoparticles was checked using Wide Angle X-Ray Scattering (WAXS) and Transmission Electron Microscopy (TEM); both the effects of different amounts of montmorillonite and silane were measured on molecular weights and on thermal and rheological properties, using Size Exclusion Chromatography (SEC), Differential Scanning Calorimetry (DSC), thermogravimetric analyses (TGA), and rheological analyses. It was found that even very low amounts (0.1% w/w) of nanoparticles greatly affect nanocomposites properties. Unmodified montmorillonite tends to decrease molecular weights, deactivating the catalytic system used for ROP of lactide, but when epoxy silane is present molecular weights increase. Melt crystallization temperatures increase with modified nanoparticles, which enhance crystallization process. TGA analyses show that when pure montmorillonite is present, nanocomposites have lower thermal stability with respect to standard PLA; when silane is used thermal stability can get much higher than standard PLA as silane content increases. The rheological behaviour of nanocomposites shows that melt viscosity is far higher than that of standard PLA at low shear rates and also a marked shear thinning behaviour can be achieved.

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