scholarly journals Highly Impact-Resistant Block Polymer-Based Thermoplastic Elastomers with an Ionically Functionalized Rubber Phase

ACS Omega ◽  
2021 ◽  
Author(s):  
Takato Kajita ◽  
Atsushi Noro ◽  
Ryoji Oda ◽  
Sadaharu Hashimoto
Keyword(s):  
Thermoplastic Elastomers ◽  
Block Polymer ◽  
Rubber Phase

Polyolefin Thermoplastic Elastomer Blends

1991 ◽  
Vol 64 (3) ◽  
pp. 469-480 ◽  
Author(s):  
E. N. Kresge
Keyword(s):  
Triblock Copolymer ◽  
Crosslink Density ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Rubber Phase ◽  
Styrene Butadiene Styrene ◽  
Weather Resistance ◽  
Theological Properties ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Abstract Thermoplastic elastomers based on blends of polyolefins are an important family of engineering materials. Their importance arises from a combination of rubbery properties along with their thermoplastic nature in contrast to thermoset elastomers. The development of polyolefin thermoplastic elastomer blends follows somewhat that of thermoplastic elastomers based on block copolymers such as styrene-butadiene-styrene triblock copolymer and multisegmented polyurethane thermoplastic elastomers which were instrumental in showing the utility of thermoplastic processing methods. Polyoleflns are based on coordination catalysts that do not easily lend themselves to block or multisegmented copolymer synthesis. However, since polyolefins have many important attributes favorable to useful elastomeric systems, there was considerable incentive to produce thermoplastic elastomers based on simple α-olefins by some means. Low density, chemical stability, weather resistance, and ability to accept compounding ingredients without compromising physical properties are highly desirable. These considerations led to the development of polyolefin thermoplastic elastomer blends, and two types are now widely used: blends of ethylene-propylene rubber (EPM) with polypropylene (PP) and blends of EPDM and PP in which the rubber phase is highly crosslinked. This article reviews the nature of these blends. Both physical and Theological properties are very dependent on the morphology and crosslink density of the blend system. Moreover, the usefulness of practical systems depends extensively on compounding technology based on added plasticizers and fillers.

Dynamically Vulcanized Thermoplastic Elastomers

1996 ◽  
Vol 69 (3) ◽  
pp. 476-494 ◽  
Author(s):  
S. Abdou-Sabet ◽  
R. C. Puydak ◽  
C. P. Rader
Keyword(s):  
Elevated Temperatures ◽  
Elastic Recovery ◽  
Great Majority ◽  
Thermoplastic Elastomers ◽  
Dynamic Vulcanization ◽  
Product Lines ◽  
Wide Range ◽  
Rubber Phase ◽  
Definition Of ◽  
Thermoplastic Polyolefin

Abstract Thermoplastic elastomers (TPEs) exhibit the functional properties of conventional thermoset rubber, yet can be processed on thermoplastic fabrication equipment. The great majority of TPEs have hetero-phase morphology, whether the TPE is derived from block copolymers, rubber-plastic compositions or ionomers. Generally speaking, the hard domains (or the ionic clusters) undergo dissociation at elevated temperatures, thus allowing the material to flow. When cooled, the hard domains again solidify and provide tensile strength at normal use temperatures. The soft domains give the material its elastomeric characteristics. In this review article, the focus is on rubber-plastic polymer compositions as a group of TPEs which have achieved significant growth in the marketplace in the last two decades. The growth has been primarily in the nonpolar (olefinic) elastomer/polyolefin thermoplastic materials because of the wide range of products generated, their performance and their significant acceptance by the automotive sector in applications requiring elastic recovery. The field of TPEs based on polyolefin rubber-plastic compositions has grown along two distinctly different product lines or classes: one class consists of a simple blend and classically meets the definition of a thermoplastic elastomeric olefin (TEO), commonly called a thermoplastic polyolefin (TPO) in earlier literature. In the other class, the rubber phase is dynamically vulcanized, giving rise to thermoplastic vulcanizates (TPVs), named elastomeric alloys (EAs) in some previous literature. Both the simple blends and the dynamically vulcanized TPEs have found wide industrial application. It is the dynamically vulcanized TPE that has the performance characteristics required for true thermoset rubber replacement applications. The first TPE introduced to the market based on a crosslinked rubber-plastic composition (1972) was derived from W. K. Fisher's discovery of partially crosslinking the EPDM phase of EPDM/polypropylene (PP). Fisher controlled the degree of vulcanization by limiting the amount of peroxide, to maintain the thermoplastic processability of the blend. Crosslinking was performed while mixing, a process known as dynamic vulcanization. It is worth noting, however, that the dynamic vulcanization process and the first crosslinked EPDM/PP composition were discovered independently by Gessler and Haslett and by Holzer, Taurus and Mehnert in 1958 and 1961, respectively. Significant improvement in the properties of these blends was achieved in 1975 by Coran, Das and Patel by fully vulcanizing the rubber phase under dynamic shear while maintaining the thermoplasticity of the blend. These blends were further improved by Abdou-Sabet and Fath in 1977 by the use of phenolic curatives to improve the rubber-like properties and the flow (processing) characteristics.

Effect of Modified Natural Rubber on Properties of Thermoplastic Natural Rubber Based on Co-Polyamide Blends

2012 ◽  
Vol 626 ◽  
pp. 233-236 ◽  
Author(s):  
Boripat Sripornsawat ◽  
Charoen Nakason ◽  
Azizon Kaesaman
Keyword(s):  
Natural Rubber ◽  
Interfacial Adhesion ◽  
Grain Morphology ◽  
Thermoplastic Elastomers ◽  
Morphological Properties ◽  
Oil Resistance ◽  
Different Types ◽  
Rubber Phase ◽  
Thermoplastic Natural Rubber ◽  
Good Set

Thermoplastic elastomers (TPEs) based on natural rubber (NR)/co-polyamine (COPA) blends with different types of NR (i.e., unmodified NR, MNR, ENR-30 and ENR-50) were prepared using simple blend technique. Mechanical, elastic, oil resistant and morphological properties were investigated. The main objective was to prepare TPEs based on NR with good set property and oil resistance. It was found that the blends with modified NRs exhibited higher moduli, tensile strength, oil resistance and elastic properties than the blend with NR. This is due to higher interaction between functional groups of modified NRs (i.e., ENR and MNR) and COPA. Furthermore, the blends using modified NRs showed finer grain morphology than the blend with NR. This may be caused by higher interfacial adhesion between rubber phase and COPA matrix.

scholarly journals Development of Polypropylene-based Thermoplastic Elastomers with Crumb Rubber by Dynamic Vulcanization: A Potential Route for Rubber Recycling

2019 ◽  
Vol 64 (2) ◽  
pp. 248-254
Author(s):  
István Zoltán Halász ◽  
Dávid Kocsis ◽  
Dániel Ábel Simon ◽  
Andrea Kohári ◽  
Tamás Bárány
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Crumb Rubber ◽  
Thermoplastic Elastomers ◽  
Partial Replacement ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Dynamic Vulcanization ◽  
Screw Speed ◽  
Rubber Phase

In our current paper the preparation and properties of thermoplastic elastomer produced by dynamic vulcanization is presented and discussed. We dynamically vulcanized natural and styrene butadiene rubber (NR/SBR) phase by continuous extrusion. Dispersion and in-situ vulcanization of the rubber phase occurred simultaneously in a co-rotating twin screw extruder. We used a random polypropylene copolymer (rPP) as the thermoplastic matrix and untreated crumb rubber (CR) to partially substitute the neat fresh rubber in order to check whether this is a potential recycling route for waste rubber products. We studied the effect of various rubber formulations, various processing conditions (screw speed and configuration) and various CR particle size distributions by characterizing the mechanical performance of the thermoplastic dynamic vulcanizates (TDVs) with tensile and hardness tests and their morphology by evaluating SEM micrographs taken from the fracture surfaces of the tensile specimens. The results showed that increasing screw speed and more high-shear elements in the screw setup led to a finer dispersion of the rubber phase, resulting in improved mechanical properties. The ultimate tensile properties of the best TDVs reached 20.5 MPa in tensile strength and 550 % in strain at break. However, partial replacement of the fresh rubber with untreated CR caused a significant deterioration in mechanical properties, due to poor adhesion between the CR particles and the matrix and rubber. This suggests that some kind of pre-treatment (e.g. by microwave or other devulcanization techniques) is necessary to enhance the surface activity of the CR particles.

Thermoplastic Elastomers Based on Waste Rubber and Plastics

2004 ◽  
Vol 77 (3) ◽  
pp. 569-578 ◽  
Author(s):  
R. S. Rajeev ◽  
S. K. De
Keyword(s):  
Thermoplastic Elastomers ◽  
Waste Plastics ◽  
Rubber Latex ◽  
Elongation At Break ◽  
Rubber Waste ◽  
Waste Rubber ◽  
Rubber Tire ◽  
Rubber Phase ◽  
Recycled Rubber ◽  
Waste Polymer

Abstract This paper reviews the utilization of waste rubber and waste plastics for the preparation of thermoplastic elastomers (TPEs). TPEs based on ground rubber tire (GRT), waste EPDM rubber, waste nitrile rubber, recycled rubber, latex waste, and waste plastics are described with respect to composition and physical properties. It is found that part of the rubber phase or plastics phase or both in the rubber-plastics blend can be replaced with corresponding waste polymer for the preparation of thermoplastic elastomers. In many cases, the materials prepared from waste polymers show properties comparable to those prepared from fresh polymers. However, in some cases, the materials prepared from waste rubber or waste plastics cannot be classified as TPEs, as the blend compositions show very low elongation at break. Modification of the waste polymer or the use of compatibilizers result in stronger composites.

Formulations for thermoplastic vulcanizates based on high density polyethylene, ethylene-propylene-diene monomer, and ground tyre rubber

2011 ◽  
Vol 45 (11) ◽  
pp. 1189-1200 ◽  
Author(s):  
J. Cañavate ◽  
P. Casas ◽  
X. Colom ◽  
F. Nogués
Keyword(s):  
Mechanical Properties ◽  
High Density Polyethylene ◽  
Thermoplastic Elastomers ◽  
High Density ◽  
Ethylene Propylene Diene Monomer ◽  
Good Balance ◽  
Ethylene Propylene ◽  
Thermoplastic Vulcanizates ◽  
Ground Tyre Rubber ◽  
Rubber Phase

Thermoplastic vulcanizates (TPVs) are a specific group of the so called thermoplastic elastomers. The main characteristic is the existence of a crosslinked rubber phase obtained by dynamic vulcanization in the presence of the thermoplastic matrix. This article studies TPVs based on ground tyre rubber (GTR), high-density polyethylene, and ethylene propylene diene monomer rubber. Vulcanization is performed by a new peroxide developed to resist high temperatures and an standard one. The aim of this study is optimize the formulation in order to include GTR, while maintaining a good balance of properties in the final TPV material. The use of GTR would improve the possibilities of recovering tyre waste. A detailed study regarding the influence of each component in the final mechanical properties has been carried out. The swelling properties, ATR infrared spectroscopy, TGA, and DSC analysis indicated a high degree of crosslink and good adhesion between the matrix and the rubber phase. Morphology of the composites was assessed by scanning electron microscopy. A composite containing a combination of peroxides and 40/30/30 of HDPE, EPDM, and GTR was found to show a good balance of characteristics regarding mechanical properties, crosslinking, and adhesion between phases.

Rubber-Thermoplastic Compositions. Part I. EPDM-Polypropylene Thermoplastic Vulcanizates

1980 ◽  
Vol 53 (1) ◽  
pp. 141-150 ◽  
Author(s):  
A. Y. Coran ◽  
R. Patel
Keyword(s):  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Critical Parameters ◽  
Block Polymers ◽  
Block Polymer ◽  
High Temperature Mechanical Properties ◽  
Melting Characteristics ◽  
Thermoplastic Vulcanizates ◽  
Hard Segments ◽  
Thermoplastic Resins

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.

Extremely tough block polymer-based thermoplastic elastomers with strongly associated but dynamically responsive noncovalent cross-links

Polymer ◽  
2021 ◽  
Vol 217 ◽  
pp. 123419
Author(s):  
Takato Kajita ◽  
Haruka Tanaka ◽  
Atsushi Noro ◽  
Yushu Matsushita ◽  
Atsushi Nozawa ◽  
...  
Keyword(s):  
Thermoplastic Elastomers ◽  
Block Polymer ◽  
Cross Links
Sign in / Sign up

Export Citation Format

Share Document