scholarly journals MODIFIED WITH VARIOUS ADDITIVES ARYLALYCLIC COPOLYIMIDES AND COMPOSITE FILMS BASED ON THEIR BASIS

2021 ◽  
Vol 3 ◽  
pp. 19-35
Author(s):  
М.B. Umerzakova ◽  
◽  
R.B. Sarieva ◽  
V.D. Kravtsova ◽  
◽  
...  

lopment of arylalicyclic copolyimides based on alicyclic dianhydride, aromatic dianhydrides of benzophenone- and diphenyloxidetetracarboxylic acids with 4,4'-diaminodiphenyl oxide at various ratios of alicyclic and aromatic dianhydrides, as well as various compositions based on these copolymers with low- or other high-molecular compounds that enhance the characteristics of the polymer matrix. Composite films were formed from solutions of the obtained polymer mixtures, and their properties were studied. It was noted that at optimal ratio of components, the films have improved thermal and strength properties, etc., exceeding the analogous properties of the initial arylalicyclic copolymer, while the elasticity has acceptable values for such material. The best characteristics had the composite films formed from a ternary composition of copo-lyimide-polyethylene glycol-alkylated montmorillonite. Metal-containing composite films, along with higher thermal stability compared to unmodified copolyimide, were resistant to aggressive reagents, lower values of specific volume and surface resistance, higher viscosity values, and different colors depending on the nature of the salt. By introducing a silicon-containing compound into the copolyimide solution, the new polymer systems have been obtained, and the porous films could be formed.

2020 ◽  
Vol 869 ◽  
pp. 280-295
Author(s):  
Andrei Didenko ◽  
Danila Kuznetcov ◽  
Gleb Vaganov ◽  
Valentina Smirnova ◽  
Elena Popova ◽  
...  

The series of compositions containing thermodynamically incompatible flexible blocks of aliphatic polyesters and rigid blocks of aromatic bis (urethane) imides in the volume of polymers was obtained on the basis of multiblock (segmented) poly (urethane-imides) and related aromatic polyimides. The series includes segmented poly (urethane-imides) with different relative content of flexible and rigid blocks, non-segregating mixtures of poly (urethane-imides) and thermoplastic partially crystalline polyimide, statistical copolymers of poly (urethane-imide) with imide, and non-segregating mixtures of statistical copolymers with thermoplastic polyimide. The derived polymer systems were studied using thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The deformation and strength properties of film samples are determined. It is shown that the properties of the studied polymers change as their content of imides blocks increases, and the transition from thermoplastic poly (urethane-imide) elastomers to thermoplastic polyimides is observed.


2021 ◽  
pp. 009524432110290
Author(s):  
Mukaddes Sevval Cetin ◽  
Ozan Toprakci ◽  
Omer Suat Taskin ◽  
Abdullah Aksu ◽  
Hatice Aylin Karahan Toprakci

This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.


2013 ◽  
Vol 750-752 ◽  
pp. 1919-1923 ◽  
Author(s):  
Guo Xian Zhou ◽  
Ming Wei Yuan ◽  
Lin Jiang ◽  
Ming Long Yuan ◽  
Hong Li Li

The laponite-poly (L-lactide) composite films are prepared by the method of solution blending with polylactide (PLA) and laponite. The result shows that the homogeneous and smooth composite film is prepared with 1, 4-dioxane. Thermogravimetry analysis (TG) and tensile strength studies demonstrate that the thermal stability and tensile strength are improved with the laponite added. The scanning electron microscopy (SEM) measurement indicates that the pores of composite films get uniform and network structure is more and more compact with compared to pure PLA film. The present study reveals that the laponite as a complexing agent can improve the mechanical properties and thermal stability of PLA.


Author(s):  
I.V. Smirnov ◽  
◽  
K.V. Grinyaev ◽  
A.N. Tyumentsev ◽  
A.D. Korotaev ◽  
...  

A study of the features of structural-phase state, thermal stability, mechanical properties characteristics and fracture features of V-Cr-Ta-Zr alloy after chemical-heat treatment by the method of nonequilibrium internal oxidation has been carried out. It has been established that, in contrast to chemical-heat treatment in a defect state, the effect of oxygen when introduced into a material with a stabilized structure is observed only at high concentrations. At such oxygen concentrations, which ensure the maximum binding of Zr into particles based on ZrO2, the alloy under study demonstrates a high level of thermal stability and strength properties. These effects are associated with the implementation of disperse strengthening according to the Orowan mechanism by nanosized ZrO2 particles characterized by high thermal stability. The concentration and nature of the distribution of oxygen predetermine the spatial distribution of nanosized ZrO2 particles formed during chemical-heat treatment, which manifests itself in fracture features of the material at different temperatures.


Author(s):  
Jie Liu ◽  
Yanchun Liu ◽  
Eleanor M. Brown ◽  
Zhengxin Ma ◽  
Cheng-Kung Liu

The leather industry generates considerable amounts of solid waste and raises many environmental concerns during its disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor permeability and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging. 


ACS Omega ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 6144-6153 ◽  
Author(s):  
Mohammad Mizanur Rahman Khan ◽  
Subrata Pal ◽  
Md. Mainul Hoque ◽  
Md. Rashedul Alam ◽  
Muhammad Younus ◽  
...  

Author(s):  
D M Mognonov ◽  
S V Morozov ◽  
O Zh Ayurova ◽  
E I Chernyak ◽  
V I Rodionov ◽  
...  

2020 ◽  
Vol 8 (22) ◽  
pp. 7476-7484 ◽  
Author(s):  
Xudong Zhou ◽  
Xiaoyun Liu ◽  
Zhongkai Cui ◽  
Jinlou Gu ◽  
Shaoliang Lin ◽  
...  

A new-type of hollow silica@ZIF-8 (HMS@ZIF-8) particle was successfully designed, fabricated and introduced into the fluorinated polybenzoxazole (6FPBO) matrix to prepare the HMS@ZIF-8/6FPBO composite film.


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