Generalized temperature-time characteristic of the strength and hardness of amorphous polymer materials

1967 ◽  
Vol 1 (4) ◽  
pp. 50-51
Author(s):  
A. A. Askadskii ◽  
G. L. Slonimskii
Keyword(s):  
Amorphous Polymer ◽  
Time Characteristic ◽  
Polymer Materials ◽  
Temperature Time

Stimulating changes in the elastic modulus of polymer materials by molecular photochromism

RSC Advances ◽  
2014 ◽  
Vol 4 (108) ◽  
pp. 62920-62925 ◽  
Author(s):  
Yuhuan Jin ◽  
Daniel Harrington ◽  
Aaron A. Rachford ◽  
Jeffrey J. Rack
Keyword(s):  
Elastic Modulus ◽  
Amorphous Polymer ◽  
Polymer Materials

Photonastic effects are observed in an amorphous polymer via irradiation of a pendant photoreversible photochrome.

scholarly journals Adhesion-strength and tribotechnical properties of machine-building composite polymer coatings

2021 ◽  
Vol 264 ◽  
pp. 05032
Author(s):  
Soyibjon Negmatov ◽  
T Ulmasov ◽  
M Karshiyev ◽  
Z Makhammadjonov ◽  
O Abdulayev ◽  
...  
Keyword(s):  
Adhesion Strength ◽  
Adhesive Strength ◽  
Polymer Coatings ◽  
Machine Building ◽  
Polymer Materials ◽  
Tribotechnical Properties ◽  
Extreme Character ◽  
Relative Change ◽  
Temperature Time ◽  
Degree Of Filling

The article presents the results of studies of adhesive, strength and tribotechnical properties of composite polycaproamide polymer materials and coatings based on them for mechanical engineering purposes. It has been established that the relative change in the adhesion strength depends on the degree of filling in air and in argon has an extreme character passing through a maximum for coatings based on PCA with aluminum oxide, and for coatings made of PCA with copper oxide, it has a complex character. The formation of adhesive, strength, and tribotechnical properties of filled polycaproamide coatings was also studied. At the same time, it was found that by adjusting the temperature-time technological modes, it is possible to increase the adhesive, strength, and tribotechnical characteristics of composite polycaproamide coatings for machine-building purposes.

scholarly journals Reflectance According to Cell Size, Foaming Ratio and Refractive Index of Microcellular Foamed Amorphous Polymer

2019 ◽  
Vol 20 (23) ◽  
pp. 6068 ◽  
Author(s):  
Sung Woon Cha ◽  
Soo-hyun Cho ◽  
Joo Seong Sohn ◽  
Youngjae Ryu ◽  
Jeonghun Ahn
Keyword(s):  
Refractive Index ◽  
Cell Size ◽  
Amorphous Polymer ◽  
High Specific Surface Area ◽  
Polymer Materials ◽  
Light Passing ◽  
Foaming Process ◽  
Microcellular Foaming ◽  
Cell Structures ◽  
A Cell

Microcellular foamed plastic has a cell size of approximately 0.1 to 10 microns inside a foamed polymer and a cell density in the range of 109 to 1015 cells/cm3. Typically, the formation of numerous uniform cells inside a polymer can be effectively used for various purposes, such as lightweight materials, insulation and sound absorbing materials. However, it has recently been reported that these dense cell structures, which are induced through microcellular foaming, can affect the light passing through the medium, which affects the haze and permeability and causes the diffused reflection of light to achieve high diffuse reflectivity. In this study, the effects of cell size, foaming ratio and refractive index on the optical performance were investigated by applying the microcellular foaming process to three types of amorphous polymer materials. Thus, this study experimentally confirmed that the advantages of porous materials can be implemented as optical properties by providing a high specific surface area as a small and uniform cell formed by inducing a high foaming ratio through a microcellular foaming process.

scholarly journals Peculiarities of High-Energy Induction Heating during Surface Hardening in Hybrid Processing Conditions

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1354
Author(s):  
Vadim Y. Skeeba ◽  
Vladimir V. Ivancivsky ◽  
Nikita V. Martyushev
Keyword(s):  
Power Consumption ◽  
Hardened Layer ◽  
High Energy ◽  
Time Characteristic ◽  
Process Equipment ◽  
Volumetric Heating ◽  
Integral Temperature ◽  
Processing Modes ◽  
Heating Scheme ◽  
Temperature Time

This paper presents the results obtained when combining mechanical and surface-thermal operations, using the same process equipment. The paper also demonstrates the possibility of implementing high-energy heating with high-frequency currents, and proposes using an integral temperature–time characteristic as the main parameter to specify surface quenching modes. The numerical values of the integral temperature–time characteristic are to be related to the processing modes and the depth of hardening. The experiments confirmed that an increase in the capacity will be commensurate with an increase in power consumption when a volumetric heating scheme (with a hardening depth of 0.5 mm) is realized. However, during the realization of a volumetric heating scheme, when the 0.7 mm depth of the hardened layer is at the boundary of the “hot” depth of the current penetration into the metal (the beginning of the intermediate heating scheme), the increase in the processing capacity will be higher than that in power consumption.

scholarly journals DYNAMIC THREE-POINTS-BENDING TEST MODE OF TWO AMORPHOUS POLYMER MATERIALS (PMMA, PC) FOR THEIR VISCOELASTIC AND MECHANICAL CHARACTERIZATION

2021 ◽  
Vol 9 (08) ◽  
pp. 448-453
Author(s):  
Ayarema Afio ◽  
◽  
Komlan Lolo ◽  
Kodjo Attipou ◽  
Komla Assogba Kassegne ◽  
...  
Keyword(s):  
Industrial Development ◽  
Mechanical Characterization ◽  
Amorphous Polymer ◽  
Amorphous Polymers ◽  
Polymer Materials ◽  
Bending Test ◽  
Embedded Test ◽  
Practical Applications ◽  
Viscoelastic Characteristics

This paper presents an approach to classifying amorphous polymer materials. Temperature is This classification involves the determination of mechanical and viscoelastic characteristics considered a descriptive variable to clarify the specific field of practical applications of amorphous polymers. according to the reference temperature characterizing the behaviour of polymer materials. The mechanical and viscoelastic characteristics of amorphous polymers such as methyl poly-methacrylate (PMMA), polycarbonate (PC) and imide poly ether (PEI) are determined through the three-point dynamically embedded test carried out in an adiabatic close enclosure. The complex dissipative or conservative modules according to the temperature are represented. The results obtained show that the fluidity index of these materials is linked to their viscosity, which is a determining property which is decisive for the choice of the technique of the application of the material. Our method of measuring properties is therefore, in principle, comparable to the techniques used in industrial development.

Solid wood joints by in situ welding of structural wood constituents

Holzforschung ◽  
2004 ◽  
Vol 58 (1) ◽  
pp. 45-52 ◽  
Author(s):  
B. Gfeller ◽  
A. Pizzi ◽  
M. Zanetti ◽  
M. Properzi ◽  
F. Pichelin ◽  
...  
Keyword(s):  
Amorphous Polymer ◽  
Solid Wood ◽  
Polymer Materials ◽  
Cross Linking ◽  
Structural Application ◽  
Wood Fibres ◽  
Entanglement Network ◽  
Melted Material ◽  
C Nmr

Abstract Mechanically-induced wood flow welding, without any adhesive, is here shown to rapidly yield wood joints satisfying the relevant requirements for structural application. The mechanism of mechanically-induced vibrational wood flow welding is shown to be due mostly to the melting and flowing of the amorphous polymer materials interconnecting wood cells, mainly lignin, but also some hemicelluloses. This causes the partial detachment of long wood cells and wood fibres and the formation of an entanglement network in a matrix of melted material which then solidifies. Thus, it forms a wood cell/fibre entanglement network composite having a molten lignin polymer matrix. During the welding period, some of the detached wood fibres no longer held by the interconnecting material are pushed out of the joint as excess fibre. Cross-linking chemical reactions of lignin and of carbohydrate-derived furfural also occur. Their presence has been identified by CP-MAS 13C NMR. These reactions are, however, relatively minor contributors during the very short welding period. Their contribution increases after welding has finished, explaining why relatively longer holding times under pressure after the end of welding contribute strongly to obtaining a good bond.

Synthesis of Ceramics/Polymer Nanocomposites Protonic Conducting Membrane

1998 ◽  
Vol 548 ◽  
Author(s):  
I. Honma ◽  
S. Hirakawa ◽  
J.M. Bae
Keyword(s):  
High Temperature ◽  
Polymer Nanocomposites ◽  
High Temperatures ◽  
Chemical Sensors ◽  
Amorphous Polymer ◽  
Sol Gel ◽  
Hybrid Membrane ◽  
Polymer Materials ◽  
Polyethylene Oxides ◽  
Electrochemical Devices

ABSTRACTHigh temperature protonic conducting polymer membrane provides new technological applications in the electrochemical devices including electrochromic displays, chemical sensors, fuel cells and others. Organic/inorganiaianocomposites membrane consists of SiO2/PEO (Polyethylene Oxides) hybrid are remarkable family of isotropic, amorphous polymer materials, which has been synthesized through sol-gel processes. The hybrid membrane doped with acidic surfactant molecules shows good protonic conductivities at high temperatures above 100C. The membrane was found to be thermally stable at high temperatures because of the inorganic SiO2 framework in the composites matrix.

Protonic Conducting Properties of Sol-Gel derived Organic/Inorganic Nanocomposites Membrane doped with Acidic Functional Molecules

1999 ◽  
Vol 576 ◽  
Author(s):  
I. Honma ◽  
Y. Takeda ◽  
J. M. Bae
Keyword(s):  
Fuel Cells ◽  
High Temperature ◽  
Phosphotungstic Acid ◽  
Amorphous Polymer ◽  
Sol Gel ◽  
Polymer Membranes ◽  
Hybrid Membrane ◽  
Polymer Materials ◽  
Polyethylene Oxides ◽  
Inorganic Nanocomposites

ABSTRACTHigh temperature protonic conducting polymer membranes provide new technological applications in electrochemicaldevices including electrochromic displays, chemicalsensors and fuel cells. Organic/inorganimanocomposite membranes consisting of SiO2 /PEO (Polyethylene Oxides) hybrid are a remarkable family of isotropic, flexible, amorphous polymer materials, which have been synthesized through sol-gel processes. The hybrid membrane doped with acidic moieties such as monododecylphosphate or phosphotungstic acid shows good protonic conductivities at temperatures above 100°C. The protonic conducting membrane was found to be thermally stable at temperatures because of the inorganic SiO2 framework in the nanocomposites matrix.

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