The Effect of the Substitution Position of Nitrogen Atoms on Copolyimide Properties

2014 ◽  
Vol 1079-1080 ◽  
pp. 66-69
Author(s):  
Yu Han Li ◽  
Ri Zhe Jin
Keyword(s):  
Mechanical Properties ◽  
Water Uptake ◽  
Water Stability ◽  
Side Chains ◽  
Thermally Stable ◽  
Dimensional Changes ◽  
Film Forming ◽  
Diamine Monomer

Two containing nitrogen diamine monomer, 2-(4-aminophenyl)-5-aminopyrimidine (PAPRM) and 2,5-two(dimethyl amino methylene)-1,4-((paraamino) phenyl)benzene(DMAPB), was synthesized. The corresponding copolyimide containing 40–80 mol % PAPRM and DMAPB were prepared. The copolymers showed excellent solubility and good film-forming capability. Most of the SPI membranes were both tough and flexible and thermally stable up to 330 °C.With increasing content of the nitrogen atoms, water uptake of membranes and dimensional changes also remarkable decrease. Compared with the main chains containing nitrogen atoms, the side chains type displayed excellent water stability and good mechanical properties.

A Study of the Nitrogen-Containing Heterocycles on Copolyimide Properties for Proton Exchange Membranes

2013 ◽  
Vol 401-403 ◽  
pp. 563-566 ◽  
Author(s):  
Yu Han Li ◽  
Wei Jian Wang ◽  
Yu Fei Chen ◽  
Lei Wang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Proton Conductivity ◽  
Water Uptake ◽  
Main Chain ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Membrane Properties ◽  
Dimensional Changes ◽  
Sulfonated Polyimide

Containing pyrimidine and pyridine monomers were incorporated respectively into the main chain of a sulfonated polyimide in order to investigate the effect of nitrogen-containing heterocycles on membrane properties such as water uptake and proton conductivity. With increasing content of the nitrogen-containing heterocycles, water uptake of membranes and dimensional changes remarkable decrease. The copolymer showed higher thermal stability (desulfonation temperature up to 330 °C) and reasonable good mechanical properties. These membranes also showed higher proton conductivity, which was comparable or even higher than Nafion 117.

Synthesized and Preparation of Side Chains Containing Nitrogen Atoms Sulfonated Polyimide Membranes

2014 ◽  
Vol 1046 ◽  
pp. 39-42
Author(s):  
Yu Han Li ◽  
Ri Zhe Jin
Keyword(s):  
Mechanical Strength ◽  
Liquid Water ◽  
Sulfonic Acid ◽  
Water Stability ◽  
Side Chains ◽  
Sulfonated Polyimide ◽  
Interchain Interactions ◽  
Sulfonic Acid Groups ◽  
Polyimide Membranes ◽  
Diamine Monomer

To improve the performance of sulfonated polyimide (SPI) membrane, especially to heighten water stability. A side chains containing nitrogen atoms sulfonated diamine monomer, 2,5-two (dimethyl amino methylene)-1,4-((paraamino) phenyl) benzene (DMAPB), was synthesized. A series of sulfonated polyimide (SPI) were prepared from DMAPB, 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) and sulfonated diamine (ODADS). The effects of side chains containing nitrogen atoms on SPI membrane are investigated. The basic nitorgen atom introduced in the side chains could effectively resist membrane swelling due to the strong interchain interactions through basic nitorgen atom and sulfonic acid groups. The copolymer SPI 40 showed higher water stability, it could maintain mechanical strength after being soaked in 100 °C liquid water for more than 1000 h.

Synthesis of highly thermally stable divanillic acid-derived polyamides and their mechanical properties

Polymer ◽  
2021 ◽  
pp. 123907
Author(s):  
Kazuma Yagura ◽  
Yunfan Zhang ◽  
Yukiko Enomoto ◽  
Tadahisa Iwata
Keyword(s):  
Mechanical Properties ◽  
Thermally Stable

Improvement of mechanical properties of chitosan-based films via physical treatment of film-forming solution

2015 ◽  
Vol 158 ◽  
pp. 66-72 ◽  
Author(s):  
Wasina Thakhiew ◽  
Manida Champahom ◽  
Sakamon Devahastin ◽  
Somchart Soponronnarit
Keyword(s):  
Mechanical Properties ◽  
Physical Treatment ◽  
Film Forming

scholarly journals Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Water Uptake ◽  
Significant Influence ◽  
Water Immersion ◽  
Water Diffusion ◽  
Polybutylene Terephthalate ◽  
Chemical Changes ◽  
Water Ingress ◽  
Effect Of Water

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.

scholarly journals The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Rheological Properties ◽  
Silver Carp ◽  
Shear Tests ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Forming ◽  
Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

Novel and processable polyimides with a N-benzonitrile side chain: thermal, mechanical and gas separation properties

RSC Advances ◽  
2015 ◽  
Vol 5 (33) ◽  
pp. 26040-26050 ◽  
Author(s):  
Mohammad Dinari ◽  
Hashem Ahmadizadegan
Keyword(s):  
Gas Separation ◽  
Side Chain ◽  
Thermally Stable ◽  
Side Group ◽  
Diamine Monomer

A series of organo-soluble and thermally stable polyimides with N-benzonitrile side group were synthesized from a new diamine monomer, 3-(bis(4-aminophenyl)amino)benzonitrile with different aromatic dianhydrides via thermal or chemical imidization.

scholarly journals The impact of molded pulp product process on the mechanical properties of molded Bleached Chemi-Thermo-Mechanical Pulp

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Claire Dislaire ◽  
Yves Grohens ◽  
Bastien Seantier ◽  
Marion Muzy
Keyword(s):  
Mechanical Properties ◽  
Water Uptake ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Water Immersion ◽  
Young Modulus ◽  
Drying Time ◽  
Mechanical Pulp ◽  
Hygroscopic Properties ◽  
The Impact

AbstractThis study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time, and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 30h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.

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