Novel Styrenic Thermoplastic Elastomers from Blends with Special Reference to Compatibilization and Dynamic Vulcanization

2005 ◽  
Vol 78 (5) ◽  
pp. 893-909 ◽  
Author(s):  
J. D. Patel ◽  
M. Maiti ◽  
K. Naskar ◽  
Anil K. Bhowmick
Keyword(s):  
Special Reference ◽  
Interaction Parameter ◽  
Functional Performance ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Dynamic Vulcanization ◽  
Vulcanized Rubber ◽  
Styrene Acrylonitrile ◽  
Modified Polystyrene ◽  
Styrene Butadiene

Abstract A thermoplastic elastomer (TPE) is a rubbery material with final properties and functional performance similar to those of a conventional vulcanized rubber at ambient temperature, yet it can be processed in a molten condition as a thermoplastic polymer at elevated temperature. The main objectives of the present investigation are: to prepare novel styrenic-based thermoplastic elastomers based on blends of a thermoplastic (polystyrene or styrene acrylonitrile) with a rubber (styrene butadiene or ethylene vinylacetate) and to investigate the interaction between various polymers with special reference to compatibilization via oxazoline-modified polystyrene or oxazoline-modified styrene acrylonitrile and dynamic vulcanization. Styrene acrylonitrile/ethylene vinylacetate blends are found to exhibit better overall properties, especially tensile strength, elongation at break and tension set. The solubility or interaction parameter and the morphology of the blends are the key parameters, which basically govern the final properties of blends. Physical properties of these blends have been correlated with the interaction parameter and final morphology.

High Strength - Low Hardness Thermoplastic Elastomers from Ethylene-Butene Copolymers and Low Density Polyethylene

2008 ◽  
Vol 81 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Sandeep Tembhekar ◽  
Madhuchhanda Maiti ◽  
Jinu Jacob George ◽  
Anjan Biswas ◽  
Anil K. Bhowmick ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Functional Performance ◽  
High Strength ◽  
Thermoplastic Elastomer ◽  
Ethylene Vinyl Acetate ◽  
Thermoplastic Elastomers ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Vulcanized Rubber ◽  
Rubbery Material

Abstract A thermoplastic elastomer (TPE) is a rubbery material with final properties and functional performance similar to those of a conventional vulcanized rubber at ambient temperature, yet it can be processed as a thermoplastic at elevated temperature. The main objective of the present investigation was to prepare novel olefinic thermoplastic elastomers based on blends of a thermoplastic i.e. low density polyethylene (PE) and new ethylene-butene copolymers (PEB), which would have higher strength and lower hardness compared to the existing TPEs. The 70:30 PEB: PE blend exhibited the best properties. Ethylene vinyl acetate was found to work as compatibilizer at lower loadings in these blends. The resultant blends were of low hardness (60–80 Shore A) and high strength (26–33 MPa). The interaction parameter and the morphology of the blends were the key parameters, which governed the final properties of blends.

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.

Translucent Thermoplastic Elastomers

2009 ◽  
Vol 82 (1) ◽  
pp. 94-103
Author(s):  
Maria D. Ellul ◽  
D. R. Hazelton
Keyword(s):  
Thermal Stability ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
New Materials ◽  
Dynamic Vulcanization ◽  
Ethylene Propylene ◽  
Fluid Delivery ◽  
Compression Set ◽  
Ethylene Content

Abstract Thermoplastic elastomer vulcanizates, TPVs, having the property of optical translucence have been prepared by dynamic vulcanization. The new materials are based on a polypropylene homopolymer principally containing propylene units of exactly alternating configuration and having a syndiotactic pentad fraction of at least 0.86. The dispersed elastomer phase consists of a crosslinked ethylene propylene copolymer rubber having an ethylene content of at least 74 weight %. These thermoplastic elastomer compositions have significantly lowered Gardner haze values, while maintaining the desirable properties of low compression set and thermal stability. The compositions have utility in molded mechanical rubber goods as well as extruded articles for fluid delivery applications.

Rubber-Thermoplastic Compositions. Part VII. Chlorinated Polyethylene Rubber-Nylon Compositions

1983 ◽  
Vol 56 (1) ◽  
pp. 210-225 ◽  
Author(s):  
A. Y. Coran ◽  
R. Patel
Keyword(s):  
High Strength ◽  
Fiber Composites ◽  
Short Fiber ◽  
Thermoplastic Elastomers ◽  
Chemical Bonds ◽  
Dynamic Vulcanization ◽  
Chlorinated Polyethylene ◽  
Vulcanized Rubber ◽  
High Integrity

Abstract Nylon resins and CPE rubber can be melt-blended to give compositions which have useful properties. If the rubber is cured by dynamic vulcanization, high strength oil resistant thermoplastic elastomers result. Cold milling of melt-mixed compositions results in nylon-reinforced rubber which can be mixed with curatives and press cured or statically vulcanized to give reinforced rubber compositions which resemble vulcanized rubber-short fiber composites. The reason for the high integrity of either the statically or the dynamically vulcanized composition appears to be that chemical bonds form between the rubber and plastic.

Rubber-Solvent Interaction Parameter (χ1,2) of NR/SBR Rubber Blend Solution in Determination of Crosslink Concentration for Vulcanized Rubber Blend

2015 ◽  
Vol 1134 ◽  
pp. 75-81
Author(s):  
Azreen Izzati Dzulkifli ◽  
Che Mohd Som Said ◽  
Chan Chin Han ◽  
Ahmad Faiza Mohd
Keyword(s):  
Interaction Parameter ◽  
Relaxation Method ◽  
Styrene Butadiene Rubber ◽  
Simple Extension ◽  
Butadiene Rubber ◽  
Solvent Interaction ◽  
Rubber Blends ◽  
Rubber Blend ◽  
Vulcanized Rubber ◽  
Styrene Butadiene

Crosslink concentration is an important property affecting the major characteristic of cured rubber. One of the important parameter to determine the crosslink concentration of a vulcanized rubber by swelling measurement is the rubber-solvent interaction parameter known as ‘kai’ value denoted as χ. For single rubber, the χ value is known however, the χ1,2 for rubber blends are unknown. This research concerned with the investigation to determine the χ1,2 for rubber blends solution (uncured rubber). Natural rubber (NR) and styrene butadiene rubber (SBR) rubber blends solution were blend at 7 different ratios of 100/0, 80/20, 70/30, 60/40, 50/50, 40/60 and 0/100 and were dissolved in toluene. The χ1,2 value of each rubber blends were determined based on the intrinsic viscosity measurement. Crosslink concentrations of vulcanized rubber blends obtained from the swelling measurement were then compared against the value determined from simple extension measurement (stress-relaxation method). This cross-checking was to ensure the accuracy and reliability of χ1,2 value for rubber blends solution.

Rubber-Thermoplastic Compositions. Part VIII. Nitrile Rubber Polyolefin Blends with Technological Compatibilization

1983 ◽  
Vol 56 (5) ◽  
pp. 1045-1060 ◽  
Author(s):  
A. Y. Coran ◽  
R. Patel
Keyword(s):  
Block Copolymer ◽  
Graft Copolymer ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Oil Resistance ◽  
Polyolefin Blends ◽  
Thermoplastic Vulcanizates

Abstract The results of this work suggest a practical route to hot-oil-resistant thermoplastic elastomers based on NBR and a polyolefin resin (such as polypropylene). Although these two types of polymer are normally grossly incompatible with each other, a melt-mixed blend thereof is technologically improved by the presence of a small amount of a compatibilizing block copolymer which contains both polar and nonpolar segments. Ideally, the block copolymer should contain molecular segments of the types of polymers to be compatibilized. The compatibilizing block (graft) copolymer can form in situ during melt-mixing. Dynamic vulcanization (during melt-mixing) of a compatibilized NBR-polypropylene blend produces a thermoplastic elastomer with mechanical properties about as good as those of a corresponding composition of EPDM and polypropylene (two polymers which are nearly mutually compatible in a thermodynamic sense). The compatibilizing NBR-polypropylene graft copolymer might act by reducing (molten-state) interfacial tension at the NBR-polypropylene interface and also by increasing the interfacial adhesion in the “solidified-state” composition during its use. The hot-oil resistance of the compatibilized NBR-polypropylene thermoplastic vulcanizates is excellent. Also, the NBR-polypropylene compositions can be blended with thermoplastic vulcanizates based on EPDM and polypropylene to obtain thermoplastic elastomeric compositions which exhibit both good hot oil resistance and low temperature brittleness characteristics.

The Preparation, Properties and Potential Applications of “Diimide-Hydrogenated” Styrene-Butadiene (HSBR) and Polybutadiene (HBR) Thermoplastic Elastomers

1994 ◽  
Vol 67 (2) ◽  
pp. 288-298 ◽  
Author(s):  
Dane K. Parker ◽  
Robert F. Roberts ◽  
Henry W. Schiessl
Keyword(s):  
Oxidation Resistance ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Strength Properties ◽  
Ambient Conditions ◽  
Noble Metal Catalysts ◽  
Physical Form ◽  
Allergenic Proteins ◽  
Potential Applications ◽  
Styrene Butadiene

Abstract Our unique diimide-based process for preparing HNBR latex from NDR latex without the use of hydrogen, noble metal catalysts or solvents has now been successfully extended to the preparation of hydrogenated thermoplastic elastomers latexes directly from SBR or BR latex precusors. Commercially available SBR latex such as SBR 1502 can be readily reduced to high saturation levels (95+%) via the diimide reduction technique. Latex cast films of the highly reduced elastomer show excellent ozone and oxidation resistance as expected. Unexpectedly however, the hydrogenated polymer films demonstrate high tensile strength and thermoplastic elastomer (TPE) behavior. The TPE properties have been found to be caused by polyethylene crystallites that exist even in the unstretched films under ambient conditions. Latex is an unusual physical form for a TPE material. As a latex, TPE elastomers can be fabricated into sheets or other products by simple dipping or spraying methods—methods not normally available to TPEs in bulk form. In this regard, HSBR or HBR could function as superior replacements for natural rubber (NR) latex in articles such as tubing, gloves, condoms etc., where ozone and oxidation resistance may be required or in applications where good strength properties coupled with the absence of potentially allergenic proteins and/or curatives may be desirable. Alternatively, HSBR or HBR latexes may also be conventionally coagulated and processed using standard rubber/TPE compounding techniques.

Reactive Compatibilization of Recycled Polyethylenes and Scrap Rubber in Thermoplastic Elastomers: Chemical and Radiation-Chemical Approach

2008 ◽  
Vol 81 (5) ◽  
pp. 737-752 ◽  
Author(s):  
O. Grigoryeva ◽  
A. Fainleib ◽  
J. Grenet ◽  
J. M. Saiter
Keyword(s):  
High Performance ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Size Exclusion ◽  
Dynamic Vulcanization ◽  
Polyethylene Matrix ◽  
Radiation Chemical ◽  
Reactive Compatibilization ◽  
Exclusion Chromatography ◽  
Rubber Component

Abstract Reactive compatibilization of recycled low- or high-density polyethylenes (LDPE and HDPE, respectively) and ground tire rubber (GTR) via chemical interactions of pre-functionalized components in their blend interface has been carried out. Polyethylene component was functionalized with maleic anhydride (MAH); as well, the rubber component was modified via functionalization with MAH or acrylamide (AAm) using chemically or irradiation (γ-rays) induced grafting techniques. The grafting degree and molecular mass distribution of the functionalized polymers have been measured via FTIR and Size Exclusion Chromatography (SEC) analyses, respectively. Additional coupling agents such as p-phenylene diamine (PDA) and polyamide fiber were used for producing some thermoplastic elastomer (TPE). Thermoplastic elastomer materials based on synthesized reactive polyethylenes and GTR as well as ethylene-propylenediene monomer rubber (EPDM) were prepared by dynamic vulcanization of the rubber phase inside thermoplastic (polyethylene) matrix and their phase structure, and main properties have been studied using DSC, DMTA and mechanical testing. As a result, high performance thermoplastic elastomers based on functionalized polyethylene and ground rubber with improved mechanical properties have been developed.

Thermoplastic Elastomer Based on Epoxidized Natural Rubber/Polyamide-12 and Co-Polyamide-12 Blends

2012 ◽  
Vol 626 ◽  
pp. 58-61 ◽  
Author(s):  
Rawviyanee Romin ◽  
Charoen Nakason ◽  
Anoma Thitithammawong
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
The Other ◽  
Epoxidized Natural Rubber ◽  
Dynamic Vulcanization ◽  
Elongation At Break ◽  
Polyamide 12

Thermoplastic elastomers based on blending of epoxidized natural rubber with 30 mol% epoxide (ENR-30) with polyamide-12 (PA-12) (i.e., ENR-30/PA-12) and blending of ENR-30 with co-polyamide-12 (ENR-30/CO-PA-12) were prepared by dynamic vulcanization technique. It was found that the dynamically cured ENR-30/PA-12 blends exhibited higher tensile strength, Youngs modulus and hardness than those of the ENR-30/CO-PA-12 blends. However, the elongation at break of the ENR-30/PA-12 blend was very poor and hence the tension set could not be determined. On the other hand, the ENR-30 contents in the dynamically cured ENR-30/CO-PA-12 influence on various properties. These include lowering of stiffness and tensile properties together with enhancing elastic properties (i.e. lower tension set and tan ) of the blends.

Sign in / Sign up

Export Citation Format

Share Document