scholarly journals Synthesis and Spectroscopic Analyses of New Polycarbonates Based on Bisphenol A-Free Components

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4437
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Beata Podkościelna
Keyword(s):  
Bisphenol A ◽  
Thermal Studies ◽  
Gel Permeation Chromatography ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Chromatography Analysis ◽  
Chemical Structures ◽  
New Synthesis ◽  
Characteristic Signal ◽  
Molecular Resonance

This paper discusses a new synthesis of bisphenol A-free polycarbonates based on four aliphatic-aromatic systems. In the first stage, different types of monomers (with/without sulfur) derived from diphenylmethane were synthesized. Then, new polycarbonates were prepared in the reactions with diphenyl carbonate (DPC) by transesterification and polycondensation reactions. Three different catalysts (zinc acetate, 4-(dimethylamino)pyridine and benzyltriethylammonium chloride) were tested. The structures of the compounds were confirmed by Nuclear Molecular Resonance spectroscopy (NMR) in each stage. The chemical structures of the obtained polycarbonates were verified by means of Attenuated Total Reflectance Fourier Transform infrared spectroscopy (ATR-FTIR). The presence of a carbonyl group in the infrared spectrum confirmed polycarbonate formation. Thermal studies by differential scanning calorimetry (DSC) were carried out to determine the melting temperatures of the monomers. A gel permeation chromatography analysis (GPC) of the polycarbonates was performed in order to investigate their molar masses. Thermal analysis proved the purity of the obtained monomers; the curves showed a characteristic signal of melting. The obtained polycarbonates were characterized as having high resistance to organic solvents, including tetrahydrofuran. The GPC analysis proved their relatively large molar masses and their low dispersity.

Preparation and properties of shape-stabilized phase change material cellulose benzoate-g-polyoxyethylene (2) hexadecyl ether with potential for thermal energy storage

2018 ◽  
Vol 89 (8) ◽  
pp. 1512-1521
Author(s):  
Na Han ◽  
Wenxin Zhang ◽  
Xiufang Wang ◽  
Xingxiang Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solid Phase ◽  
Resonance Spectroscopy ◽  
Thermal Reliability ◽  
Scanning Calorimetry ◽  
Chemical Structures

It is a worldwide challenge to efficiently use renewable resources to solve the current energy shortage. The existing cellulose-based material is incapable of proper power storage. In this study, a series of cellulose benzoate-g-polyoxyethylene (2) hexadecyl ether (CB-g-E2C16) solid–solid phase change materials were synthesized with cellulose as the skeleton and polyoxyethylene (2) hexadecyl ether (E2C16) as a functional side chain. The skeleton cellulose and benzoyl chloride restrict the free movement of the molecular chains of E2C16 above the phase transition temperature, leading to a solid–solid phase change. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy were performed to investigate the chemical structures. The thermal energy-storage properties, thermal reliability and thermal stability of the CB-g-E2C16 were investigated by differential scanning calorimetry and thermogravimetry (TG) methods. The analysis results indicated that the E2C16 chains were successfully grafted onto the cellulose benzoate (CB) backbone and the copolymers exhibited typical solid–solid phase transition behavior. The enthalpy and degree of substitution of graft copolymers CB-g-E2C16 could be adjusted by changing the feeding ratio of the raw materials, reaction temperature and post-processing methods of CB. TG analysis results showed that the CB-g-E2C16 copolymers possessed good thermostability and they keep their stability up to 278℃. Compared with pure cellulose, CB-g-E2C16 copolymers could be dissolved in dimethyl sulfoxide and most of them could be dissolved in N, N-dimethylformamide.

scholarly journals Analysis of Bio-Based Fatty Esters PCM’s Thermal Properties and Investigation of Trends in Relation to Chemical Structures

2019 ◽  
Vol 9 (2) ◽  
pp. 225 ◽  
Author(s):  
Rebecca Ravotti ◽  
Oliver Fellmann ◽  
Nicolas Lardon ◽  
Ludger Fischer ◽  
Anastasia Stamatiou ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Phase Change ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Arachidic Acid ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Fatty Esters ◽  
Latent Heat Storage ◽  
Chemical Structures

As global energy demand increases while primary sources and fossil fuels’ availability decrease, research has shifted its focus to thermal energy storage systems as alternative technologies able to cover for the mismatch between demand and supply. Among the different phase change materials available, esters possess particularly favorable properties with reported high enthalpies of fusion, low corrosivity, low toxicity, low supercooling, thermal and chemical stability as well as biodegradability and being derived from renewable feedstock. Despite such advantages, little to no data on the thermal behavior of esters is available due to low commercial availability. This study constitutes a continuation of previous works from the authors on the investigation of fatty esters as novel phase change materials. Here, methyl, pentyl and decyl esters of arachidic acid, and pentyl esters of myristic, palmitic, stearic and behenic acid are synthesized through Fischer esterification with high purities and their properties are studied. The chemical structures and purities are confirmed through Attenuated Total Reflectance Infrared Spectroscopy, Gas Chromatography coupled with Mass Spectroscopy and Nuclear Magnetic Resonance Spectroscopy, while the determination of the thermal properties is performed through Differential Scanning Calorimetry and Thermogravimetric Analysis. In conclusion, some correlations between the melting temperatures and the chemical structures are discovered, and the fatty esters are assessed based on their suitability as phase change materials for latent heat storage applications.

Halogenated methacrylate-based aluminum oxide (Al2O3) nanocomposites

2015 ◽  
Vol 30 (6) ◽  
pp. 762-772
Author(s):  
Kathikar Abdul Wasi ◽  
Sakvai Mohammed Safiullah ◽  
Kottur Anver Basha
Keyword(s):  
Aluminum Oxide ◽  
Polymer Matrix ◽  
Glycidyl Methacrylate ◽  
Morphological Changes ◽  
Thermal Studies ◽  
Gel Permeation Chromatography ◽  
Decomposition Temperature ◽  
Scanning Calorimetry ◽  
Initial Decomposition Temperature ◽  
Mixing Techniques

The aim of the work is to prepare the halogenated methacrylate-based polymer nano-aluminum oxide (Al2O3) composites and to study the effect of incorporated nano-Al2O3 on morphological and thermal studies. A functional 2,4,6-tribromophenyl methacrylate- co-glycidyl methacrylate copolymer microspheres (poly(TBPMA- co-GMA); pTG) by emulsion solvent evaporation techniques, whereas (2,4,6-tribromophenyl methacrylate- co-glycidyl methacrylate)-Al2O3 nanocomposites (pTG-Al2O3 nanocomposites) were prepared by solution mixing techniques. The pTG and its Al2O3 nanocomposites were structurally characterized by Fourier transform infrared (FTIR) spectroscopy. Thermal studies of pTG and its Al2O3 nanocomposites were carried out by thermogravimetric analysis and differential scanning calorimetry . The molecular weight of the pTG was determined by gel permeation chromatography. The size distribution and morphology of the pTG and its Al2O3 nanocomposites were determined by scanning electron microscopy (SEM). The FTIR results reveal that there is no significant interaction between the polymer matrix and Al2O3 nanoparticle. The significant increase in the initial decomposition temperature and glass transition temperature of pTG-Al2O3 nanocomposites compared to its polymer was due to the incorporation of nano-Al2O3 in the polymer matrix. The SEM observation provides the information about the morphological changes that arise in polymer matrix due to the incorporation of nano-Al2O3.

scholarly journals Synthesis and Characterization of Low-Cost Cresol-Based Benzoxazine Resins as Potential Binders in Abrasive Composites

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2995
Author(s):  
Artur Jamrozik ◽  
Mateusz Barczewski ◽  
Grzegorz Framski ◽  
Daniel Baranowski ◽  
Paulina Jakubowska ◽  
...  
Keyword(s):  
Low Cost ◽  
2D Nmr ◽  
Additional Analysis ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Voc Emission ◽  
Chemical Structures ◽  
Oxazine Ring ◽  
Nmr Techniques

A series of cresol-based benzoxazines were synthesized for potential application as a polymer matrix in abrasive composites. The chemical structures of the obtained benzoxazine resins were investigated in detail using Fourier transform infrared spectroscopy (FTIR) and hydrogen-1 as well as carbon-13 nuclear magnetic resonance spectroscopy (1H NMR, 13C NMR) with an additional analysis using two-dimensional NMR techniques (2D NMR 1H-1H COSY, 1H-13C gHSQC and gHMBC). Structural analysis confirmed the presence of vibrations of -O-C-N- at ~950 cm−1 wavenumber, characteristic for an oxazine ring. The thermal properties of benzoxazine monomers were examined using differential scanning calorimetry (DSC) analysis. The polymerization enthalpy varied from 143.2 J/g to 287.8 J/g. Thermal stability of cresol-based benzoxazines was determined using thermogravimetry (TGA) analysis with additional analysis of the amount of volatile organic compounds (VOC) emitted from the synthesized benzoxazines during their crosslinking by static headspace coupled with gas chromatography technique (HS-GC). The amount of residual mass significantly differed between all synthesized polybenzoxazines in the range from 8.4% to 21.2%. The total VOC emission for benzoxazines decreased by 46–77% in reference to a conventional phenolic binder. The efficiency of abrasive composites with the benzoxazine matrix was evaluated based on abrasion tests. Performed analyses confirmed successful synthesis and proper chemical structure of cresol-based benzoxazines. All the experiments indicated that benzoxazines based on different cresol isomers significantly differ from each other. Good thermal performance and stability of the abrasive composites with the polybenzoxazine matrix and significantly lower VOC emission allow us to state that benzoxazines can be a promising and valuable alternative to the phenolics and a new path for the development of modern, eco-friendly abrasives.

Chemical modification of nitrile rubber in the latex stage by functionalizing phosphorylated cardanol prepolymer: A bio-based plasticizer and a renewable resource

2018 ◽  
Vol 51 (2) ◽  
pp. 99-129 ◽  
Author(s):  
Satyajit Samantarai ◽  
Ahindra Nag ◽  
Nitesh Singh ◽  
Debabrata Dash ◽  
Amit Basak ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Gel Permeation Chromatography ◽  
Renewable Resource ◽  
Mechanical Analysis ◽  
Resonance Spectroscopy ◽  
Butadiene Rubber ◽  
Scanning Calorimetry ◽  
Flow Behavior Index ◽  
Diphenyltetrazolium Bromide ◽  
Better Than

The present investigation deals with the functionalization of acrylonitrile butadiene rubber (NBR) by chemically grafting phosphorylated cardanol prepolymer (PCP) onto its backbone chain. The grafting of PCP onto NBR was accomplished in the latex stage successfully using benzoyl peroxide as the free radical initiator. The functionalized NBR (PCP- g-NBR) is characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and gel permeation chromatography. PCP- g-NBR exhibited an increase in molecular weight (4.4%) with an increase in the polydispersity. The grafting parameters have been optimized using “Taguchi L9 table” and the optimum conditions were found to be “3 phr of initiator concentration, 15 phr of the PCP concentration, reaction temperature of 70°C and reaction time of 6 h.” The percentage grafting and grafting efficiency were calculated to be 7.28 and 80.37%, respectively, under optimum processing conditions. The PCP- g-NBR exhibited a reduction in Wallace plasticity number as well as the Mooney viscosity and an enhanced plasticity retention index (PRI) as compared to neat NBR. The rheological measurements exhibited a higher flow behavior index for PCP- g-NBR than the NBR itself. Differential scanning calorimetry and dynamic mechanical analysis results exhibited a decrease in glass transition temperature on functionalization of NBR confirming enhanced plasticization. Thermogravimetric analysis results displayed an increase in thermal stability of the functionalized NBR than that of virgin NBR. The physico-mechanical properties of the PCP- g-NBR vulcanizates were at par with or even better than the neat NBR vulcanizates. 3-(4,5-Dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide assay and hemolysis studies indicated NBR and PCP- g-NBR are nontoxic and biocompatible.

Novel allyl and propenyl monomers for modification of the bismaleimide resins, with excellent dielectric properties and high glass transition temperatures

2019 ◽  
Vol 32 (1) ◽  
pp. 116-126
Author(s):  
Chunyan Qu ◽  
Jiaying Chang ◽  
Changwei Liu ◽  
Dezhi Wang ◽  
Wanbao Xiao ◽  
...  
Keyword(s):  
Glass Transition ◽  
Bisphenol A ◽  
Dielectric Constants ◽  
Resonance Spectroscopy ◽  
Transition Temperatures ◽  
Melting Points ◽  
Scanning Calorimetry ◽  
Bismaleimide Resin ◽  
Glass Transition Temperatures ◽  
Bismaleimide Resins

Two new monomers were prepared by the reaction of 2-allylphenol and 4,4′-biphenyldicarbonyl chloride under different reaction conditions. The monomers were characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The curing processes of N, N-4,4′-bismaleimidodiphenylmethyene with 4,4′-bis(2-allylphenyl) biphenyldicarbonylate (BABC) and 4,4′-bis(2-propenylphenyl benzoate) ether (BPBE) were studied by rheological analysis and differential scanning calorimetry. Melting points of two monomers, BABC and BPBE, are 64°C and 121°C, respectively. The ABMI [4,4′-bis(2-allylphenyl)biphenyl bismaleimide] and PBMI [4,4′-bis(2-propenylphenyl)biphenyl bismaleimide] resins showed exothermic peaks at 233°C and 204°C, respectively. The measured melting points are significantly lower than that of the traditional bismaleimide resin which is modified by allyl bisphenol A. Dynamic mechanical analysis of the materials showed glass transition temperatures of ABMI and PBMI to be in the range of 213–258°C and 302–339°C, respectively. Thermogravimetric analysis of the cured resins showed 5% weight loss for ABMI and PMBI at 437°C and 428°C, along with char residues of 35.6–39.5%, respectively, at 800°C under nitrogen atmosphere. Furthermore, dielectric constants of propenyl-modified resins were lower (2.46–3.10) with dissipation factors of 0.0034–0.0036, compared with those of allyl bisphenol A resins.

Controlled Synthesis and Processing of a Poly(L-lactide-co-ε-caprolactone) Copolymer for Biomedical Use as an Absorbable Monofilament Surgical Suture

2014 ◽  
Vol 894 ◽  
pp. 172-176 ◽  
Author(s):  
Sujitra Ruengdechawiwat ◽  
Runglawan Somsunan ◽  
Robert Molloy ◽  
Jintana Siripitayananon ◽  
Valerie J. Franklin ◽  
...  
Keyword(s):  
Gel Permeation Chromatography ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Surface Appearance ◽  
Analytical Technique ◽  
Surgical Suture ◽  
The Matrix ◽  
Hot Drawing ◽  
Matrix Morphology ◽  
Uniform Diameter

Poly (L-lactide-co-ε-caprolactone) 75:25 % mol, P(LL-co-CL), was synthesized via bulk ring-opening polymerisation (ROP) using a novel tin (II) alkoxide initiator, [Sn (Oct)]2DEG, at 130°C for 48 hrs. The effectiveness of this initiator was compared withthe well-known conventional tin (II) octoateinitiator, Sn (Oct)2. The P(LL-co-CL) copolymersobtained were characterized using a combination of analytical technique including: nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), thermogravimetry (TG) and gel permeation chromatography (GPC). The P(LL-co-CL) was melt-spun into monofilament fibres of uniform diameter and smooth surface appearance. Modification of the matrix morphology was then built into the as-spun fibresvia a series of controlled off-line annealing and hot-drawing steps.

scholarly journals Effect of E-Beam Irradiation on Thermal and Mechanical Properties of Ester Elastomers Containing Multifunctional Alcohols

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1043 ◽  
Author(s):  
Marta Piątek-Hnat ◽  
Kuba Bomba ◽  
Jakub Pęksiński ◽  
Agnieszka Kozłowska ◽  
Jacek G. Sośnicki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Properties ◽  
Sebacic Acid ◽  
Gel Permeation Chromatography ◽  
Tensile Tests ◽  
Synthesis Process ◽  
Resonance Spectroscopy ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Water Contact

The aim of this work was to investigate the thermal and mechanical properties of novel, electron beam-modified ester elastomers containing multifunctional alcohols. Polymers tested in this work consist of two blocks: sebacic acid–butylene glycol block and sebacic acid–sugar alcohol block. Different sugar alcohols were utilized in the polymer synthesis: glycerol, sorbitol, xylitol, erythritol, and mannitol. The polymers have undergone an irradiation procedure. The materials were irradiated with doses of 50 kGy, 100 kGy, and 150 kGy. The expected effect of using ionizing radiation was crosslinking process and improvement of the mechanical properties. Additionally, a beneficial side effect of the irradiation process is sterilization of the affected materials. It is also worth noting that the materials described in this paper do not require either sensitizers or cross-linking agent in order to perform radiation modification. Radiation-modified poly(polyol sebacate-co-butylene sebacate) elastomers have been characterized in respect to the mechanical properties (quasi-static tensile tests), cross-link density, thermal properties (Differential Scanning Calorimetry (DSC)), chemical properties: Fourier transform infrared spectroscopy (FTIR), and wettability (water contact angle). Poly(polyol sebacate-co-butylene sebacate) preopolymers were characterized with nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR) and gel permeation chromatography (GPC). Thermal stability of cross-linked materials (directly after synthesis process) was tested with thermogravimetric analysis (TGA).

scholarly journals Synthesis of Eugenol-Based Silicon-Containing Benzoxazines and Their Applications as Bio-Based Organic Coatings

Coatings ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 88 ◽  
Author(s):  
Jinyue Dai ◽  
Shimin Yang ◽  
Na Teng ◽  
Yuan Liu ◽  
Xiaoqing Liu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Moisture Absorption ◽  
High Hardness ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Chemical Structures ◽  
Ring Opening Reaction ◽  
Ft Ir ◽  
Excellent Adhesion

In this work, several bio-based main-chain type benzoxazine oligomers (MCBO) were synthesized from eugenol derivatives via polycondensation reaction with paraformaldehyde and different diamine. Afterwards, their chemical structures were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance Spectroscopy (1H-NMR). The curing reaction was monitored by Differential Scanning Calorimetry (DSC) and FT-IR. The polybenzoxazine films were prepared via thermal ring-opening reaction of benzoxazine groups without solvent, and their thermodynamic properties, thermal stability, and coating properties were investigated in detail. Results indicated that the cured films exhibited good thermal stability and mechanical properties, showing 10% thermal weight loss (Td10%) temperature as high as 408 °C and modulus at a room temperature of 2100 MPa as well as the glass transition temperature of 123 °C. In addition, the related coatings exhibited high hardness, excellent adhesion, good flexibility, low moisture absorption, and outstanding solvent resistance.

scholarly journals P(N-Phenylmaleimide-Alt-Styrene) Introduced with 4-Carboxyl and Its Effect on the Heat Deflection Temperature of Nylon 6

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2330 ◽  
Author(s):  
Yufei Liu ◽  
Min He ◽  
Daohai Zhang ◽  
Qian Zhao ◽  
Yang Li ◽  
...  
Keyword(s):  
Dynamic Viscosity ◽  
Gel Permeation Chromatography ◽  
Nylon 6 ◽  
Mechanical Analysis ◽  
Radical Copolymerization ◽  
Resonance Spectroscopy ◽  
Scanning Calorimetry ◽  
Free Radical Copolymerization ◽  
Ft Ir ◽  
Heat Deflection Temperature

P(N-phenylmaleimide-alt-styrene) (P(NPMI-alt-St)) and P(N-(4-carboxyphenyl)maleimide-alt-styrene) (P(CPMI-alt-St)) were designed and synthesized via free radical copolymerization. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) were used to confirm the structure of P(NPMI-alt-St) and P(CPMI-alt-St). Next, the effect of P(CPMI-alt-St) on the heat deflection temperature (HDT) of nylon 6 was studied. In comparison to the PA6/P(NPMI-alt-St) blend, with the addition of 10 wt %, the HDT value of the PA6/P(CPMI-alt-St) blend increased by 15.7 °C, and the glass transition temperature (Tg) by Dynamic mechanical analysis (DMA) increased 2.3 °C. According to the analysis of DMA, dynamic viscosity, and the SEM of PA6 and its blends, P(CPMI-alt-St) promoted its compatibility with PA6, and promoted the storage modulus and dynamic viscosity of the blends. Thus, the introduction of 4-carboxyl can significantly improve the effect of P(CPMI-alt-St) on the heat resistance modification of nylon 6.

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