Rubber-Thermoplastic Compositions. Part V. Selecting Polymers for Thermoplastic Vulcanizates

1982 ◽  
Vol 55 (1) ◽  
pp. 116-136 ◽  
Author(s):  
A. Y. Coran ◽  
R. P. Patel ◽  
D. Williams
Keyword(s):  
Plastic Material ◽  
Elastic Recovery ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Entanglement Density ◽  
Surface Energies ◽  
Molecular Length ◽  
Thermoplastic Vulcanizates ◽  
Plastic Components ◽  
Critical Chain

Abstract Based on a few characteristics of the pure rubber and plastic components, rubber-plastic combinations can be selected, with a high probability of success, to give thermoplastic vulcanizates (by dynamic vulcanization) of good mechanical integrity and elastic recovery. The characteristics used in the selection are estimated surface energies, crystallinity of the hard phase (plastic) material and the critical chain length, of the rubber molecules, for entanglement. The best compositions are prepared when the surface energies of the rubber and plastic material are matched, when the entanglement molecular length of the rubber is low (high entanglement density) and when the plastic material is crystalline. Of course, it is required that neither the plastic, nor the rubber decompose in the presence of the other at temperatures required for melt mixing. Also, a curing system is required, appropriate for the rubber under the conditions of melt-mixing.

Effect of Sulfur Donor on Properties of Thermoplastic Vulcanizates Based on NR/PP

2012 ◽  
Vol 626 ◽  
pp. 54-57 ◽  
Author(s):  
Chanida Manleh ◽  
Charoen Nakason ◽  
Natinee Lopattananon ◽  
Azizon Kaesaman
Keyword(s):  
Storage Modulus ◽  
Crosslink Density ◽  
Dynamic Properties ◽  
Complex Viscosity ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Thermoplastic Vulcanizates ◽  
Pp Blends ◽  
Thermal Stability Of ◽  
Sulfur Donor

Thermoplastic vulcanizates based on natural rubber and polypropylene blend (NR/PP) was prepared via dynamic vulcanization by melt mixing process at 180°C and a rotor speed of 60 rpm. Three types of vulcanizing agent (i.e., Tetramethyl thiuram disulfide (TMTD), 4,4 Dithiodimorpholine (DTDM) and Dipentamethylene thiuram tetrasulfide (Tetrone A)) were used to cure the rubber phase of NR/PP blends. Influence loading levels of sulfur donor at 1, 2 and 3 phr on dynamic properties and crosslink density were studied. The result showed that the dynamically cured NR/PP blends with Tetrone A gave higher mechanical properties, storage modulus, complex viscosity, and crosslink density with the lower value of tanδ than those of the blends with TMTD and DTDM. Furthermore, the storage modulus, complex viscosity and crosslink density of TPVs increased with increasing loading levels for all types of sulfur donor. It was also found that thermal stability of dynamically cured NR/PP blends is higher than that of the pure NR.

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.

Experimental Investigations for Rapid Moulding Solution of Plastics Using Polyjet Printing

2011 ◽  
Vol 701 ◽  
pp. 15-20 ◽  
Author(s):  
Rupinder Singh ◽  
Varinderjit Singh
Keyword(s):  
Plastic Material ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Experimental Investigations ◽  
Support Material ◽  
Economic Point ◽  
Measuring Machine ◽  
Plastic Components ◽  
Polyjet Printing

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate the rapid moulding (RM) solutions for plastic components using polyjet printing (PP) technique. Starting from the identification of component/benchmark, prototypes with three different type of plastic material were produced, at different orientation and support material. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the plastic components produced. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. This process ensures rapid production of pre-series technological prototypes and proof of concept at less production cost and time.

Dynamic Vulcanization of NR/PCL Blends: Effect of Rotor Speed on Morphology, Tensile Properties and Tension Set

2019 ◽  
Vol 798 ◽  
pp. 337-342 ◽  
Author(s):  
Chanchai Thongpin ◽  
Theeraphat Tanprasert
Keyword(s):  
Young’S Modulus ◽  
Shear Force ◽  
Young's Modulus ◽  
Tensile Behavior ◽  
Rotor Speed ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Strain Behavior ◽  
Phase Size ◽  
Sem Micrograph

This work aimed to study effect of rotor speed during melt mixing of natural rubber/polycaprolactone (NR/PCL) on the morphology which controls mechanical properties of dynamic vulcanizate using Luperox101 as a curing agent in NR component. The rotor speeds at 60 and 80 rpm were compared. The morphology of NR/PCL vulcanizates elucidated from SEM micrograph showed that the vulcanizates exhibited NR paticles dispersed in PCL matrix. In addition, the phase size of dispersed NR should be smaller with increasing rotor speed due to the increased shear force. This large PCL domain induced stronger strain hardening in stress-strain behavior under tension. This behavior is closed to tensile behavior of PCL and appeared at the vulcanizates. In terms of modulus, Young’s modulus was concentrated and reported. The lower degradation of PCL phase during melt mixing in the vulcanizates prepared from melt mixing at rotor speed of 60 rpm was responsible for higher Young‘s modulus than that prepared from rotor speed of 80 rpm. The tension set of NR/PCL vulcanizates prepared with rotor speed of 60 was higher than that with rotor speed of 80 rpm. It was suggested by Nakason et.al. [1] that the tension set of vulcanizates should be lower than 50 % so that they could be applied for thermoplastic vulcanizates. In this system, tension set values of the vulcanizates containing PCL 30-45 wt.% were lower than 50% in both rotor speed conditions.

Thermoplastic Elastomeric Blends of Nylon-6/Acrylate Rubber: Influence of Interaction on Mechanical and Dynamic Mechanical Thermal Properties

1997 ◽  
Vol 70 (5) ◽  
pp. 798-814 ◽  
Author(s):  
Abhijit Jha ◽  
Anil K. Bhowmick
Keyword(s):  
Morphological Structure ◽  
Nylon 6 ◽  
Spectroscopic Studies ◽  
Dynamic Mechanical Properties ◽  
Epoxy Acid ◽  
Substantial Improvement ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Two Phase ◽  
Dynamic Mechanical

Abstract Nylon-6 and acrylate rubber (ACM) were melt blended in a Brabender Plasticorder at 220 °C and 40 rpm rotor speed. The reactive nature of the blend is reflected in the mixing torque behavior of the blends at different compositions. The solubility characteristics of the blends in formic acid solution gives an approximate idea of the amount of nylon-6 grafted onto ACM and vice-versa. A reaction mechanism is proposed based on the well known epoxy—amine and epoxy—acid reactions and is confirmed by infrared spectroscopic studies of the blends. The influence of interaction between the two polymers on the mechanical and the dynamic mechanical properties of the blends is analyzed in detail, and the results are interpreted on the basis of the formation of nylon—ACM graft copolymer at the interfaces. The dynamic mechanical thermal analysis (DMTA) reveals a two phase morphological structure, indicating incompatibility of the blend components. The grafting reaction results in dramatic increase in both the storage modulus and the Young's modulus of blends. The presence of grafted rubber chains is reflected in the secondary transition of the rubber loss peak at higher temperature. Also, a substantial improvement in the damping properties of the blends in the service temperature range (i.e., 25 to 175 °C) is revealed from the DMTA results. The dynamic vulcanization of the ACM phase during melt mixing improves the elongation at break values of the blends.

Properties of Fire Retardant Thermoplastic Vulcanizates from NR/PP Blends Filled with Aluminium Trihydrate and Magnesium Hydroxide with Reference to the Effect of Mixing Methods

2013 ◽  
Vol 844 ◽  
pp. 297-300 ◽  
Author(s):  
Alif Walong ◽  
Azizon Kaesaman ◽  
Tadamoto Sakai ◽  
Natinee Lopattananon
Keyword(s):  
Thermal Stability ◽  
Magnesium Hydroxide ◽  
Fire Retardant ◽  
Melt Mixing ◽  
Dynamic Vulcanization ◽  
Elongation At Break ◽  
Processing Cost ◽  
Fire Retardant Properties ◽  
Pp Blends ◽  
Internal Mixer

Blends of natural rubber (NR) and polypropylene (PP) with composition of 60/40 %wt were prepared by using an internal mixer to obtain thermoplastic vulcanizate (TPV). Aluminium trihydrate (ATH) and magnesium hydroxide (MH) were used as fillers to improve thermal stability and fire retardant properties. Three different mixing methods were used to incorporate the fillers into the TPVs, which were (1) compounding of NR and filler followed by dynamic vulcanization of NR during blending with PP, (2) compounding of NR with a half part of filler (and oil) followed by dynamic vulcanization of NR when blending with PP before adding another half part of filler into the blend (3) melt mixing of PP, NR and filler followed by dynamic vulcanization during mixing. The incorporation of ATH and MH decreased tensile strength and elongation at break of the TPVs, but increased the thermal stability and LOI%. From this work, the mixing of filler with NR/PP blend by using method 3 provided better balance of tensile, thermal and fire resistant properties and processing cost reduction.

Mixing Methods Influencing on Properties of Epoxidized Natural Rubber/Polypropylene Thermoplastic Vulcanizates

2013 ◽  
Vol 844 ◽  
pp. 109-112 ◽  
Author(s):  
Chesidi Hayichelaeh ◽  
Charoen Nakason ◽  
Anoma Thitithammawong
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Dynamic Mechanical Properties ◽  
Epoxidized Natural Rubber ◽  
Melt Mixing ◽  
Dynamic Mechanical ◽  
Thermoplastic Vulcanizates ◽  
Mixing Method ◽  
Internal Mixer

Epoxidized natural rubber (ENR)/Polypropylene (PP) thermoplastic vulcanizates were prepared by melt mixing method in an internal mixer. Influences of different mixing methods for incorporation of processing oil into the TPVs on tensile and dynamic mechanical properties of the TPVs and crystallinity of the PP were investigated. Results show that distribution of processing oil in the ENR/PP TPV is important due to the processing oil can promote and in the same time can interrupt an improvement in elastomeric properties of the TPV. Incorporation of processing oil into the ENR phase by preparation of oil extended ENR (the mixing method 1) before mixing with the PP was the better way to produce the TPV. It promoted the TPV with superior tensile and dynamic mechanical properties than the TPVs prepared from the mixing method 2 and 3 in which the processing oil was directly added into the PP phase. Furthermore, the TPV from the mixing method 1 had less effect of processing oil on the PP crystallization.

Experimental Investigations for Statistically Controlled Rapid Moulding Solution of Plastics Using Polyjet Printing

2010 ◽  
Author(s):  
Rupinder Singh ◽  
Varinderjit Singh ◽  
Manohar Singh Saini
Keyword(s):  
Plastic Material ◽  
Coordinate Measuring Machine ◽  
Dimensional Accuracy ◽  
Point Of View ◽  
Experimental Investigations ◽  
Economic Point ◽  
The Past ◽  
Measuring Machine ◽  
Plastic Components ◽  
Polyjet Printing

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate statistically controlled rapid moulding (RM) solutions for plastic components using polyjet printing (PP). Starting from the identification of component/benchmark, prototypes with three different type of plastic material were prepared, at different orientations. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the components prepared. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. Final components prepared are acceptable as per ISO standard UNI EN 20286-I (1995). This process ensures rapid production of statistically controlled pre-series technological prototypes and proof of concept at less production cost and time.

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