scholarly journals Study on the Thermal Properties and Enzymatic Degradability of Chiral Polyamide-Imides Films Based on Amino Acids

2019 ◽  
Vol 9 (3) ◽  
pp. 578 ◽  
Author(s):  
Weipeng Liu ◽  
Fuyan He ◽  
Wenke Yang ◽  
Zhizhou Yang ◽  
Jinshui Yao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Thermal Properties ◽  
Volume Effect ◽  
Polymer Materials ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Degradation Rates ◽  
Enzymatic Degradability ◽  
Specific Degradation

Six kinds of chiral polyamide-imides (PAI3a–3f) have successfully been synthesized via direct polycondensation. The thermal properties of the materials were evaluated by the gravimetric analysis (TGA) and differential scanning calorimetry (DSC). A thermal test was conducted and showed that the polymers have good thermal stability. The Tg values were affected by the volume effect of the side groups, the internal plasticizing effect and the isolation effect. Polyamide-imides (PAIs) with L configuration showed higher Tg values than PAIs with D configuration. In the enzymatic degradation experiments of PAI films, the results showed that the structure of amino acids have the greatest influence on the degradation performance of PAIs relative to chirality. The PAI films with simple side groups and L configurations were easier to degrade. The degradation rate of natural chiral PAIs were higher than those of non-natural chiral PAIs. This makes it possible to develop polymer materials with specific degradation rates.

Decellularized liver-regenerative 3D printing biomaterials for cell-based liver therapies via a designed procedure combined with papain-containing reagent treatments and supercritical fluids

2021 ◽  
pp. 1-8
Author(s):  
Ching-Cheng Huang
Keyword(s):  
3D Printing ◽  
Thermo Gravimetric Analysis ◽  
Extraction Process ◽  
Gravimetric Analysis ◽  
Collagen Scaffolds ◽  
Scanning Calorimetry ◽  
Porcine Liver ◽  
Good Thermal Stability ◽  
Decellularized Liver ◽  
Liver Collagen

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.

The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

2018 ◽  
Vol 33 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Patrycja Bazan ◽  
Stanisław Kuciel ◽  
Mariola Sądej
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Average Length ◽  
Flexural Modulus ◽  
Basalt Fiber ◽  
Charpy Impact ◽  
Mechanical And Thermal Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

scholarly journals Interaction between Copper Oxide Nanoparticles and Amino Acids: Influence on the Antibacterial Activity

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 792 ◽  
Author(s):  
Elena Badetti ◽  
Loris Calgaro ◽  
Laura Falchi ◽  
Alessandro Bonetto ◽  
Cinzia Bettiol ◽  
...  
Keyword(s):  
Amino Acids ◽  
Light Scattering ◽  
Inductively Coupled Plasma ◽  
Antimicrobial Agents ◽  
Copper Ions ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Ion Release ◽  
Scanning Calorimetry ◽  
Cuo Nps

The increasing concern about antibiotic-resistance has led to the search for alternative antimicrobial agents. In this effort, different metal oxide nanomaterials are currently under investigation, in order to assess their effectiveness, safety and mode of action. This study focused on CuO nanoparticles (CuO NPs) and was aimed at evaluating how the properties and the antimicrobial activity of these nanomaterials may be affected by the interaction with ligands present in biological and environmental media. Ligands can attach to the surface of particles and/or contribute to their dissolution through ligand-assisted ion release and the formation of complexes with copper ions. Eight natural amino acids (L-Arg, L-Asp, L-Glu, L-Cys, L-Val, L-Leu, L-Phe, L-Tyr) were chosen as model molecules to investigate these interactions and the toxicity of the obtained materials against the Gram-positive bacterium Staphylococcus epidermidis ATCC 35984. A different behavior from pristine CuO NPs was observed, depending on the aminoacidic side chain. These results were supported by physico-chemical and colloidal characterization carried out by means of Fourier-Transform Infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermo-Gravimetric Analysis (TGA), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and light scattering techniques (Dynamic Light Scattering (DLS), Electrophoretic Light Scattering (ELS) and Centrifugal Separation Analysis (CSA).

Thermal properties of a series of tetrafunctional fluorene-based oxazines/P-a blends

2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Mechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Primary Amines ◽  
Resonance Spectroscopy ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Good Thermal Stability

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).

scholarly journals Tough Materials Through Ionic Interactions

2021 ◽  
Vol 9 ◽  
Author(s):  
Linda Salminen ◽  
Erno Karjalainen ◽  
Vladimir Aseyev ◽  
Heikki Tenhu
Keyword(s):  
Thermal Properties ◽  
Ion Pairs ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Polymer Materials ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Shape Stability ◽  
Chemical Crosslinks ◽  
Unique Approach

This article introduces butyl acrylate-based materials that are toughened with dynamic crosslinkers. These dynamic crosslinkers are salts where both the anion and cation polymerize. The ion pairs between the polymerized anions and cations form dynamic crosslinks that break and reform under deformation. Chemical crosslinker was used to bring shape stability. The extent of dynamic and chemical crosslinking was related to the mechanical and thermal properties of the materials. Furthermore, the dependence of the material properties on different dynamic crosslinkers—tributyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C4ASA) and trihexyl-(4-vinylbenzyl)ammonium sulfopropyl acrylate (C6ASA)—was studied. The materials’ mechanical and thermal properties were characterized by means of tensile tests, dynamic mechanical analysis, differential scanning calorimetry, and thermogravimetric analysis. The dynamic crosslinks strengthened the materials considerably. Chemical crosslinks decreased the elasticity of the materials but did not significantly affect their strength. Comparison of the two ionic crosslinkers revealed that changing the crosslinker from C4ASA to C6ASA results in more elastic, but slightly weaker materials. In conclusion, dynamic crosslinks provide substantial enhancement of mechanical properties of the materials. This is a unique approach that is utilizable for a wide variety of polymer materials.

Preparation and Characterization of Tetradecanol Microcapsule Phase Change Materials by Emulsion Polymerization

2015 ◽  
Vol 1089 ◽  
pp. 137-141 ◽  
Author(s):  
Xiao Qiu Song ◽  
Long Di Cao ◽  
Dan Dan Xu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Result Show ◽  
Ft Ir ◽  
Latent Heats ◽  
Test Result

In this study, it was aimed at preparing and characterizating of poly (methyl methacrylate) (PMMA) shell microcapsules containing tetradecanol as phase change materials (PCMs) for thermal energy storage. The tetradecanol microcapsules were characterized by using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The test result show that the contents of tetradecanol in microcapsules nearly 57.5% and the latent heats of melting and freezing were found to be 120.7 and 118.4 J/g. TGA analyses also indicated that the microPCMs degraded in two steps and have good thermal stability.

High thermally stable thermosetting polyimides derived from a carborane-containing tetramine

2018 ◽  
Vol 31 (5) ◽  
pp. 548-556 ◽  
Author(s):  
Yuane Wu ◽  
Chen Feng ◽  
Jiping Yang ◽  
Gong Chen
Keyword(s):  
Thermal Properties ◽  
Carbon Fiber ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
The Novel ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Thermal Imidization ◽  
Excellent Thermal Property ◽  
Thermosetting Polyimides

In this study, we report the preparation of thermosetting polyimides (PIs) based on carborane-containing tetramine and their characterizations. The novel tetramine 1,2-bis(4-(3,5-diaminobenzoic acid phenyl ester))carborane (CBNH) was synthesized and characterized firstly. Then, it was used in the preparation of two kinds of branched imide oligomers via the method of thermal imidization. The cure behavior of the obtained phenylethynyl-terminated oligomers was investigated by differential scanning calorimetry. The effect of carborane substituent on the thermal properties of PIs was studied by comparing with a similar structure without the carborane group. The thermal properties of PIs and carbon fiber/PI composites were investigated by thermal gravimetric analysis and dynamic mechanical analysis, respectively. Because of the introduction of high steric hindrance of carborane structure, the resulting thermosets and carbon fiber/PI composites had excellent thermal property with a high char yield at 800°C (>66.5%) and a high glass transition temperature (up to 500°C), respectively.

Optically active polymer: synthesis and characterization of new optically active poly (hydrazide-imide)s incorporating L- leucine

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Specific Rotation ◽  
Optically Active ◽  
Gravimetric Analysis ◽  
Optically Active Polymer ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Good Thermal Stability ◽  
H Nmr

AbstractThis paper deals with the polycondensation between a chiral diacyl chloride (N,N′-Pyromelliticdiimido-di-L-leucine chloride) and six different dihydrazides. The corresponding poly (hydrazide-imide)s which have been obtained in quantitative yields are moderately soluble in polar aprotic solvents, have good thermal stability and optical activity. The synthetic compounds have been characterized by IR, UV and 1H NMR spectroscopy, elemental analysis and specific rotation. The thermal properties of the polymers (10 and 15) have been studied by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC).

Mechanical and Thermomechanical Properties of Nylon6T/66/PPS Blends

2015 ◽  
Vol 815 ◽  
pp. 503-508
Author(s):  
Qi Zhang ◽  
Xiao Lin Luo ◽  
Mei Lin Zhang ◽  
Xiao Jun Wang ◽  
Gang Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Flexural Modulus ◽  
Thermomechanical Properties ◽  
Polymer Materials ◽  
Scanning Calorimetry ◽  
Polymer Blending ◽  
Good Thermal Stability ◽  
Aromatic Polyamides ◽  
Scanning Electron ◽  
Better Than

Polymer blending is a very important and widely used method for the modification of polymer materials. However, little attention has been paid to the Semi-aromatic Polyamides with PPS blends. In this article, we investigate the properties of Poly (phenylene sulfide) (PPS) blends with Poly (hexamethylene terephthalamide/hexamethylene hexanediamide) (nylon 6T/66). The structure, mechanical properties of nylon 6T/66 and (PPS) blends were studied by scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TG). The results indicate that the blends have good thermal stability and the tensile strength, flexural strength and flexural modulus of the blends are better than the PA6T/66 but worse than that of the PPS.

Effect of functional nitrile groups on curing behaviors and thermal properties of epoxy resins as advanced matrix materials

2012 ◽  
Vol 19 (4) ◽  
pp. 347-350 ◽  
Author(s):  
Heng Guo ◽  
Jiandong Zhang ◽  
Zhiran Chen ◽  
Junji Wei ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Epoxy Resins ◽  
Side Chain ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Rheological Analysis ◽  
Glass Transition Temperatures ◽  
Epoxy Blends

AbstractThis paper reports the preparation of the amine/epoxy blends with various amines such as 4,4′-diaminodiphenylsulfone (DDS), one nitrile side chain-containing diamine (BDB), and phthalonitrile-containing amine (APN). Differential scanning calorimetry (DSC), rheological analysis, and thermal gravimetric analysis (TGA) were used to evaluate the curing behaviors and thermal properties of amine/epoxy blends with the effect of functional nitrile groups of amines. Interestingly, an amine/epoxy blend exhibited double curing reactions. The cured epoxy copolymers exhibited high glass transition temperatures (>220°C) and excellent thermal stabilities having 5% weight loss temperature in the range of 375°C to 383°C.

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