Elastomeric Block Polymers

1980 ◽  
Vol 53 (3) ◽  
pp. 728-771 ◽  
Author(s):  
P. Dreypuss ◽  
L. J. Fetters ◽  
D. R. Hansen

Abstract Development of new thermoplastic elastomers is a challenge for future years. It is a difficult challenge because existing thermoplastic elastomers offer a wide variety of prices and properties with good performance price ratios. Most advancements will probably be accomplished by blending or compounding or by slight molecular modifications of existing products. However, a new thermoplastic elastomer can not be ruled out if new technology is developed. With new applications yet to be discovered, and as existing markets mature, the growth of new and existing thermoplastic elastomers should be exciting in the years ahead.

1987 ◽  
Vol 60 (3) ◽  
pp. 83-117 ◽  
Author(s):  
Norman R. Legge

Abstract It is a great pleasure to return to Montreal to receive the Charles Goodyear Medal at this joint meeting of the American Chemical Society, Rubber Division, and the Rubber Chemistry Division, Chemical Institute of Canada. This occasion has given me a delightful opportunity to renew old friendships in both organizations and to visit again my graduate school at McGill. First of all, I thank the Awards Committee and the Executive Committee of the Rubber Division for electing me to this high honor which I share with my many collaborators who were with me during those exciting years, and with the Shell Companies. The subject of the lecture is “Thermoplastic Elastomers,” specifically the triblock copolymers based on styrene and dienes, or hydrogenated dienes. Previously I have used the subtitle, “A Successful Innovation,” where I have defined “innovation” as the successful commercialization of a new technology, process, or product. In this lecture, I shall discuss the background of the innovation, the impact of it upon the thermoplastic elastomer field, and some of the early history of thermoplastic elastomers, which I believe you will find interesting.


1980 ◽  
Vol 53 (1) ◽  
pp. 141-150 ◽  
Author(s):  
A. Y. Coran ◽  
R. Patel

Abstract Thermoplastic elastomers are rubbery materials which can be fabricated by techniques usually associated with thermoplastic resins. Classical elastomers rely upon the crosslinked network, developed during vulcanization, to provide the retractive forces of rubber type elasticity. Thermoplastic elastomers contain rubber domains and resinous thermoplastic domains. The thermoplasticity results from the melting characteristics of the hard thermoplastic phase, while the rubber properties arise from the rubbery domains. Thermoplastic elastomers are, therefore, almost by definition, heterogeneous in their phase morphology. Such materials can be blends or block polymers. In the case of block polymers, the rubbery phase is not crosslinked chemically. However, hard or resinous phase domains occur as the hard segments of the block polymer which separate from the composition by agglomeration during cooling from the molten state. These domains act both as well-bonded reinforcing filler particles and as crosslinks. This is, of course, because the hard blocks are connected to the soft or rubbery segments by primary chemical bonds. In the case of the blend compositions, the hard and soft domains are separate polymeric species. However, there must be some form of interaction between the domains if useful properties are to be realized. Recently, uncured or partially cured EPDM rubber has been blended with polyolefin resin to make thermoplastic elastomer-like compositions. However, these compositions suffer deficiencies in performance as well as in certain aspects of fabricability. Only poor to fair performance at temperatures above 70°C in air or in oil has been achieved with the uncured to partially cured compositions. More recently, it has been found in our laboratories that fully cured EPDM compositions which are fabricable as thermoplastics can be prepared. Such compositions, referred to here as thermoplastic vulcanizates, have superior strength, high-temperature mechanical properties, hot oil and solvent resistance, better compression set, etc. This report outlines critical parameters associated with these unique materials.


RSC Advances ◽  
2019 ◽  
Vol 9 (51) ◽  
pp. 29765-29771 ◽  
Author(s):  
Minghui Xu ◽  
Xianming Lu ◽  
Hongchang Mo ◽  
Ning Liu ◽  
Qian Zhang ◽  
...  

A novel energetic polymeric binder PBFMO-b-PNMMO alternative block thermoplastic elastomer was developed for metal-rich solid propellants.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 872
Author(s):  
Malgorzata Ulewicz ◽  
Alina Pietrzak

This article presents physical and mechanical properties of concrete composites that include waste thermoplastic elastomer (TPE) from the production process of car floor mats. Waste elastomer (2–8 mm fraction) was used as a substitute for fine aggregate in quantities of 2.5, 5.0, 7.5, and 10% of the cement weight. For all series of concrete, the following tests were carried out: compression strength, bending tensile strength, splitting tensile strength, absorbability, density, resistance to water penetration under pressure, frost resistance, and abrasion resistance, according to applicable standards. Moreover, SEM/EDS analysis was carried out on the surface microstructure of synthesized concrete composites. It was proven that the use of production waste from the production process of car floor mats in the quantity of 2.5% does not influence the change of the concrete microstructure and it does not result in the decrease of the mechanical parameters of concrete modified with waste. All concrete modified with the addition of waste meet standards requirements after carrying out 15 cycles of freezing and thawing, and the average decrease in compression strength did not exceed 20%. Adding waste in the quantity of 2.5% allows for limiting the use of aggregate by about 5%, which is beneficial for the natural environment.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1596
Author(s):  
Peng Zhang ◽  
Yongqi Zhang ◽  
Xuan Wang ◽  
Jiaming Yang ◽  
Wenbin Han

Blending thermoplastic elastomers into polypropylene (PP) can make it have great potential for high-voltage direct current (HVDC) cable insulation by improving its toughness. However, when a large amount of thermoplastic elastomer is blended, the electrical strength of PP will be decreased consequently, which cannot meet the electrical requirements of HVDC cables. To solve this problem, in this paper, the inherent structure of thermoplastic elastomer SEBS was used to construct acetophenone structural units on its benzene ring through Friedel–Crafts acylation, making it a voltage stabilizer that can enhance the electrical strength of the polymer. The DC electrical insulation properties and mechanical properties of acetylated SEBS (Ac-SEBS)/PP were investigated in this paper. The results showed that by doping 30% Ac-SEBS into PP, the acetophenone structural unit on Ac-SEBS remarkably increased the DC breakdown field strength of SEBS/PP by absorbing high-energy electrons. When the degree of acetylation reached 4.6%, the DC breakdown field strength of Ac-SEBS/ PP increased by 22.4% and was a little higher than that of PP. Ac-SEBS, with high electron affinity, is also able to reduce carrier mobility through electron capture, resulting in lower conductivity currents in SEBS/PP and suppressing space charge accumulation to a certain extent, which enhances the insulation properties. Besides, the highly flexible Ac-SEBS can maintain the toughening effect of SEBS, resulting in a remarkable increase in the tensile strength and elongation at the break of PP. Therefore, Ac-SEBS/PP blends possess excellent insulation properties and mechanical properties simultaneously, which are promising as insulation materials for HVDC cables.


1988 ◽  
Vol 61 (2) ◽  
pp. 223-237 ◽  
Author(s):  
A. U. Paeglis ◽  
F. X. O'Shea

Abstract The zinc sulfonate of EPDM, an ionic elastomer polymer, can be readily formulated into useful thermoplastic elastomer compounds having beneficial properties and processing characteristics. The thermoplastic processing characteristics of these ionic elastomers are uniquely controlled by “ionolyzers,” preferential ionic plasticizers. These additives induce thermal reversibility in the ionic crosslink and control the response of the ionic associations to temperature. Ionic elastomer compounds maintain many of the performance features characteristic of vulcanized EPDM, such as low-temperature flexibility, thermal stability, and weatherability, while providing the added advantages of heat weldability and elimination of vulcanization. We have developed a cost-effective ionic elastomer formulation that meets or exceeds the RMA recommendations for black EPDM in a demanding, high performance application, single-ply roofing membrane. High-strength lap seams can be rapidly fabricated using portable hot air welders, a technique unavailable to conventional vulcanized EPDM sheet. Other applications have been investigated for these polymers, such as hose, footwear, mechanical goods, adhesives, impact modifiers, and asphalt modifiers both as thermoplastic elastomers and as modifiers for other materials. These applications have taken advantage of the unique rheological and solubility properties of these polymers. In addition, a new polymer grade offers an advance in the ability to formulate higher strength and more highly filled and extended ionic elastomer compositions.


2015 ◽  
Vol 17 (4) ◽  
pp. 74-81 ◽  
Author(s):  
Sandra Paszkiewicz ◽  
Iwona Pawelec ◽  
Anna Szymczyk ◽  
Zbigniew Rosłaniec

Abstract This paper presents a comparative study on which type of platelets nanofiller, organic or inorganic, will affect the properties of thermoplastic elastomer matrix in the stronger manner. Therefore, poly(trimethylene terephthalate-block-poly(tetramethylene oxide) copolymer (PTT-PTMO) based nanocomposites with 0.5 wt.% of clay (MMT), graphene nanoplatelets (GNP) and graphene oxide (GO) have been prepared by in situ polymerization. The structure of the nanocomposites was characterized by transmission electron microscopy (TEM) in order to present good dispersion without large aggregates. It was indicated that PTT-PTMO/GNP composite shows the highest crystallization temperature. Unlike the addition of GNP and GO, the introduction of MMT does not have great effect on the glass transition temperature of PTMO-rich soft phase. An addition of all three types of nanoplatelets in the nanocomposites caused the enhancement in tensile modulus and yield stress. Additionally, the cyclic tensile tests showed that prepared nanocomposites have values of permanent set slightly higher than neat PTT-PTMO.


2018 ◽  
Vol 35 (1) ◽  
pp. 45-72 ◽  
Author(s):  
Lorenzo M. Polgar ◽  
Francesca Fallani ◽  
Juul Cuijpers ◽  
Patrizio Raffa ◽  
Antonius A. Broekhuis ◽  
...  

Abstract Water-swellable elastomers (WSE) constitute a class of rubbery materials that have been widely studied both in academia and industry during the last 25 years. Market pull is the major driver for the exploration of these materials. The need of WSE in several sealing applications has driven the attention of many academic researchers toward the possibility to provide a rubber with water-swelling characteristics. As commercial rubbers are hydrophobic materials, making them swell in water presents an interesting and difficult challenge. This paper reviews the scientific and patent literature on the fundamental aspects of WSE: the various synthetic approaches, the properties of the corresponding polymers (not only the swelling performance but also the mechanical behavior), and some of their applications. Particular attention is paid to the chemical structure/performance relationships of WSE. Finally, the authors speculate on a great future for WSE that can be rationally designed for improved and/or new applications.


2002 ◽  
Vol 10 (3) ◽  
pp. 409-416
Author(s):  
FRANCISCO GARCÍA-OLMEDO

Plant molecular breeding represents a new technology that adds to, rather than substitutes for, traditional breeding practice, and shares with it the same long-standing objectives: higher yield, better products, better-adapted plants. Additionally, it allows the consideration of completely new applications: pharmaceuticals, industrial products and bioremediation processes. Safety issues and the socio-economic prospects of this new technology are discussed.


MRS Advances ◽  
2021 ◽  
Author(s):  
Takeshi Aoyagi

Abstract We achieved high-throughput prediction of the stress–strain (S–S) curves of thermoplastic elastomers by combining hierarchical simulation and deep learning. ABA triblock copolymer with a phase-separated structure was used as a thermoplastic elastomer model. The S–S curves of the ABA triblock copolymers were calculated from the hierarchical simulation of self-consistent field theory calculations and coarse-grained molecular dynamics simulations. Because such hierarchical simulations require considerable computational resources, we applied a deep learning technique to accelerate the prediction. Sets of phase-separated structures and the S–S curves obtained from the hierarchical simulation were used to train a 3D convolutional neural network. Using the trained network, we confirmed that the predicted S–S curves of the untrained structures accurately reproduced the simulation results. These results will enable us to design novel polymers and phase-separated structures with desired S–S curves by high-throughput screening of a wide variety of structures. Graphic abstract


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