scholarly journals Bio-Based Aromatic Copolyesters: Influence of Chemical Microstructures on Thermal and Crystalline Properties

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 829
Author(s):  
Keling Hu
Keyword(s):  
High Performance ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Size Exclusion ◽  
Differential Scanning Calorimetric ◽  
Average Weight ◽  
Gravimetric Analysis ◽  
Excellent Thermal Stability ◽  
Future Design ◽  
Chemical Structures

Aromatic copolyesters, derived from bio-based nipagin and eugenol, were synthesized with renewable 1,6-hexandiol as the spacer. Number-average, weight-average molecular weights (Mn, Mw), and polydispersity (D) values were determined by size exclusion chromatography (SEC). Chemical structures were confirmed by 1H NMR and 13C NMR spectroscopies. Chemical microstructure analysis suggested that the nipagin and eugenol-derived units were inserted into polymer chains in an arbitrary manner. Due to the short chain of 1,6-hexanediol, the splitting of magnetically different methylene carbons, adjacent to the alcohol-oxygens, proved to be more sensitive towards sequence distributions, at the dyed level, than those from 1,10-decanediol. Thermal gravimetric analysis (TGA) demonstrated that these polyester materials have excellent thermal stability (>360 °C), regardless of the content of eugenol-derived composition incorporated. Differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD) experiments revealed the semicrystalline nature for this kind of copolyesters. The crystallinities gradually decreased with the increase of eugenol-derived composition. Thermal and crystalline properties were well discussed from the microscopic perspective. The point of this work lies in establishing guidance for future design and modification of high-performance polymer materials from the microscopic perspective.

scholarly journals Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao
Keyword(s):  
High Performance ◽  
Synergistic Interaction ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
Ether Ester

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.

scholarly journals Homogeneous Distribution of Polymerizable Coumarin Dyes for Active Few Mode POF

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1975
Author(s):  
Florian Jakobs ◽  
Kristoffer Harms ◽  
Jana Kielhorn ◽  
Daniel Zaremba ◽  
Pen Yiao Ang ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Optical Fibers ◽  
High Performance ◽  
Polymer Chains ◽  
Size Exclusion ◽  
Polymerization Process ◽  
Homogeneous Distribution ◽  
Exclusion Chromatography ◽  
Polymer Optical Fibers ◽  
Coumarin Dyes

For most kinds of active polymer optical fibers, a homogeneous distribution of dye molecules over the entire fiber length and cross section is required. In this study, chemical bonding of dyes to poly(methyl methacrylate) (PMMA) by copolymerization is achieved within the polymerization process instead of dissolving the dyes in the monomers. In combination with an improved fabrication mechanism, this leads to homogeneous dye distribution within the preforms. A method for proving the integration of the dyes into the polymer chains has been developed using high-performance liquid chromatography (HPLC) and size exclusion chromatography (SEC). Prestructured core-cladding preforms with dye-doped poly(cylohexyl methacrylate-co-methyl methacrylate)-core have been prepared with the Teflon string technique and were heat-drawn to few mode fibers.

Synthesis and properties of highly soluble branched polyimide based on 2,4,6-triaminopyrimidine

2016 ◽  
Vol 29 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Ying Chen ◽  
Rumin Huang ◽  
Qiuyu Zhang ◽  
Wanlu Sun ◽  
Xiaobo Liu
Keyword(s):  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Polymerization Process ◽  
Differential Scanning Calorimetric ◽  
X Ray Diffraction ◽  
Excellent Thermal Stability ◽  
Light Scattering Detection ◽  
Exclusion Chromatography ◽  
Combined Features ◽  
Multiangle Laser Light Scattering

A series of novel soluble polyimides was synthesized from commercially available 2,4,6-triaminopyrimidine (TAP), 2,2-bis(3,4-dicarboxylphenyl) hexafluoropropane dianhydride (6FDA), α,ω-aminopropylpoly(dimethylsiloxane) and 1,3-bis(3-aminophenoxy)benzene. TAP is the branched monomer, and polymerization process had been improved in three ways by using TAP to prepare soluble polyimides. The polyimides were characterized by Fourier transform infrared spectra, proton nuclear magnetic resonance, ultraviolet–visible spectrometer analysis, wide-angle X-ray diffraction, and size-exclusion chromatography with multiangle laser light-scattering detection. The branched polyimides showed excellent solubility both in strong polar solvents and in common low-boiling point solvents. Differential scanning calorimetric and thermogravimetric analyses showed high glass transition temperatures and excellent thermal stability for branched polyimides with moderate content of TAP. Polyimide membranes were formed at relatively low temperature, and the mechanical properties were tested. These results ensure that soluble polyimides with moderate content of TAP showed outstanding combined features and are desirable candidate materials for advanced applications.

scholarly journals Recent Advances of the Polymer Micro/Nanofiber Fluorescence Waveguide

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1086 ◽  
Author(s):  
Hongyan Xia ◽  
Tingkuo Chen ◽  
Chang Hu ◽  
Kang Xie
Keyword(s):  
Optical Waveguide ◽  
High Performance ◽  
Building Blocks ◽  
Transmission Efficiency ◽  
Photonic Devices ◽  
Polymer Chains ◽  
Polymer Materials ◽  
Optical Wave ◽  
Integrated Optical ◽  
Photonic Components

Subwavelength optical micro/nanofibers have several advantages, such as compact optical wave field and large specific surface area, which make them widely used as basic building blocks in the field of micro-nano optical waveguide and photonic devices. Among them, polymer micro/nanofibers are among the first choices for constructing micro-nano photonic components and miniaturized integrated optical paths, as they have good mechanical properties and tunable photonic properties. At the same time, the structures of polymer chains, aggregated structures, and artificial microstructures all have unique effects on photons. These waveguided micro/nanofibers can be made up of not only luminescent conjugated polymers, but also nonluminous matrix polymers doped with luminescent dyes (organic and inorganic luminescent particles, etc.) due to the outstanding compatibility of polymers. This paper summarizes the recent progress of the light-propagated mechanism, novel design, controllable fabrication, optical modulation, high performance, and wide applications of the polymer micro/nanofiber fluorescence waveguide. The focus is on the methods for simplifying the preparation process and modulating the waveguided photon parameters. In addition, developing new polymer materials for optical transmission and improving transmission efficiency is discussed in detail. It is proposed that the multifunctional heterojunctions based on the arrangement and combination of polymer-waveguided micro/nanofibers would be an important trend toward the construction of more novel and complex photonic devices. It is of great significance to study and optimize the optical waveguide and photonic components of polymer micro/nanofibers for the development of intelligent optical chips and miniaturized integrated optical circuits.

Isolation and structural elucidation of norlignan polymers from the heartwood of Cryptomeria japonica

Holzforschung ◽  
2015 ◽  
Vol 69 (3) ◽  
pp. 281-296 ◽  
Author(s):  
Yu Yanase ◽  
Kazuyuki Sakamoto ◽  
Takanori Imai
Keyword(s):  
Cryptomeria Japonica ◽  
High Performance ◽  
Chemical Structure ◽  
Size Exclusion ◽  
Spectrometric Data ◽  
Chemical Structures ◽  
Flight Mass Spectrometry ◽  
Exclusion Chromatography ◽  
Model Dimer ◽  
First Time

Abstract The norlignan (NorL) is a class of secondary metabolites, which occurs in the heartwood (hW) of certain softwood species. Although the NorL is often assumed to be secondarily altered (e.g., oxidized and/or polymerized in the hW over time), the formation and the chemical structure of oxidized/polymerized products remained unclear. In this study, we focused on the question whether an NorL oligomer/polymer exists in the hW of Cryptomeria japonica. First, NorL model polymers were prepared by horseradish peroxidase-catalyzed oxidation and their chemical structures were investigated by size exclusion chromatography-high-performance liquid chromatography (SEC-HPLC), nuclear magnetic resonance (NMR), and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Second, methanol (MeOH) extracted from the hW of C. japonica was fractionated, and one of the fractions contained NorL polymers as demonstrated by its chromatographic and spectrometric data in comparison with those of model polymers. Third, five kinds of agatharesinol (AGA) model dimers were synthesized and their chemical structures were determined. 13C-NMR signals corresponding to the model dimer structures were observed in the NMR spectrum of the natural polymer fraction. In summary, an NorL polymer was found in the hW of C. japonica, and its preliminary chemical structure was proposed for the first time.

scholarly journals Synergistic interaction of renewable nipagin and eugenol for aromatic copoly(ether ester) materials with desired performance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao
Keyword(s):  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Polybutylene Terephthalate ◽  
X Ray ◽  
Molecular Weights ◽  
Chemical Structures ◽  
Naturally Occurring ◽  
High Boiling Point ◽  
Ether Ester

AbstractNaturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) polymers. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11−xE1x and PHN11−xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability, high boiling point, and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggested that properties of this kind of poly(ether ester)s could be finely tuned by the relative content of two components for the desired applications (elastomer, rubbery) suitable for different scenarios from polyethylene glycol terephthalate (PET) and polybutylene terephthalate (PBT).

Antisolvent precipitation of hemicelluloses, lignosulfonates and their complexes from ultrafiltrated spent sulfite liquor (SSL)

Holzforschung ◽  
2018 ◽  
Vol 72 (10) ◽  
pp. 839-850 ◽  
Author(s):  
Basel Al-Rudainy ◽  
Mats Galbe ◽  
Herje Schagerlöf ◽  
Ola Wallberg
Keyword(s):  
High Performance ◽  
Product Yield ◽  
2D Nmr ◽  
Solute Concentration ◽  
Size Exclusion ◽  
Bulk Solution ◽  
Gravimetric Analysis ◽  
Degree Of Separation ◽  
Vis Spectroscopy ◽  
Spent Sulfite Liquor

AbstractThe possibility of precipitating high molecular weight (MW) softwood hemicelluloses has been investigated. Solids were precipitated from a sodium-based spent sulfite liquor with the anti-solvents acetone, ethanol and methanol and the effects of solute concentration, pH and temperature on the precipitation were studied. The product yield, degree of separation, MW and structure of the different fractions were determined using gravimetric analysis, high performance liquid chromatography (HPLC), ultraviolet–visible (UV-Vis) spectroscopy, size exclusion chromatography (SEC), and two-dimensional nuclear magnetic resonance (2D NMR). A direct correlation was found between the dielectric constant (also called relative permittivity) of the bulk solution and the yield of precipitants, based on which the separation of the solutes was predictable. The highest yield and degree of separation observed was an intercept around 76% with 47.5% acetone, which was the most efficient anti-solvent.

scholarly journals Conjugated Conductive Polymer Materials and its Applications: A Mini-Review

2021 ◽  
Vol 9 ◽  
Author(s):  
Huizhi Lu ◽  
Xunlai Li ◽  
Qingquan Lei
Keyword(s):  
High Performance ◽  
Molecular Design ◽  
Field Effect Transistors ◽  
Conductive Polymer ◽  
Polymer Materials ◽  
Light Emitting Devices ◽  
Conductive Materials ◽  
Chemical Structures ◽  
Potential Applications ◽  
Conductive Properties

Since their discovery 50 years ago, conjugated conducting polymers have received increasing attention owing to their unique conductive properties and potential applications in energy storage, sensors, coatings, and electronic devices such as organic field-effect transistors, photovoltaic cells, and light-emitting devices. Recently, these materials have played a key role in providing a more comfortable environment for humans. Consequently, the development of novel, high-performance conjugated conductive materials is crucial. In this mini-review, the progress of conjugated conductive materials in various applications and the relationship between the chemical structures and their performances is reviewed. This can aid in the molecular design and development of novel high-performance conjugated polymer materials.

Application of a fractionation technique for better understanding of the removal of natural organic matter by alum coagulation

2002 ◽  
Vol 2 (5-6) ◽  
pp. 427-433 ◽  
Author(s):  
J. van Leeuwen ◽  
C. Chow ◽  
R. Fabris ◽  
N. Withers ◽  
D. Page ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
High Performance ◽  
Relative Proportion ◽  
Water Source ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Alum Treatment ◽  
Hydrophobic Acids

To gain an improved understanding of the types of organic compounds that are recalcitrant to water treatment, natural organic matter (NOM) isolates from two drinking water sources (Mt. Zero and Moorabool reservoirs, Victoria, Australia) were separated into fractions of distinct chemical behaviour using resins. Four fractions were obtained from each water source and were organics absorbed to: (1) XAD-8 (very hydrophobic acids, VHA); (2) DAX-4 (slightly hydrophobic acids, SHA); (3) bound to an anion exchange resin (charged organics, CHAR); and (4) not absorbed or bound to resins (neutrals, NEUT). These fractions were then tested to determine the capacity of alum to remove them from water and to correlate this with the character of each isolate. The fractions were characterised by the application of high performance size exclusion chromatography (HPSEC), bacterial regrowth potential (BRP), trihalomethane formation potential (THMFP), pyrolysis gas-chromatography mass spectrometry (Py-GC-MS) and thermochemolysis. The highest removals of dissolved organic carbon (DOC) by alum treatment were in waters spiked with the CHAR fractions while the NEUT fractions were the most recalcitrant. The number average molecular weights (Mn) of DOC of the CHAR fractions before treatment were the highest, whilst those of the NEUT fractions were the lowest. After alum treatment, the Mn of the NEUT fractions were only slightly reduced. Results from Py-GC-MS and thermochemolysis indicate that the NEUT fractions had the highest relative proportion of saccharide derived organic material. Nonetheless, the BRP of waters spiked with the NEUT fractions differed markedly, indicating that organics recalcitrant to alum treatment can vary substantially in their chemical composition and capacity to support microbial growth.

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