Changes in Mixing Torque, Mechanical and Dynamic Rheological Properties of Epoxidized Natural Rubber and Copolyester Blends as Affected by Epoxidized Natural Rubber Contents

2013 ◽  
Vol 844 ◽  
pp. 69-72 ◽  
Author(s):  
Densak Kaewkabpet ◽  
Charoen Nakason ◽  
Azizon Kaesaman ◽  
Anoma Thitithammawong
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Complex Viscosity ◽  
Epoxidized Natural Rubber ◽  
Elastic Response ◽  
High Elongation ◽  
Tan Δ ◽  
Thermoplastic Natural Rubber ◽  
Low Tension ◽  
Internal Mixer

Thermoplastic natural rubber (TPNR) based on epoxidized natural rubber with 30 %mol epoxide (ENR-30) and copolyester (COPE) blends was prepared in a molten state by using roller rotor internal mixer. Effect of various ENR contents on mixing torque together with mechanical and dynamic properties of the ENR-30/COPE blends was investigated. It was found that the mixing torque and complex viscosity increased with increasing contents of the ENR in the blends. This was due to higher polarity the ENR molecules caused interaction and entanglement of the ENR molecular chains with higher viscosity. Furthermore, improvement of elastomeric properties of the ENR-30/COPE blends was clearly observed, especially in the blends with higher proportion of the ENR. These improved elastomeric properties with high elongation at break, low tension set and high storage modulus together with low tan δ. This observation correlated to higher elastic component in the blend caused promoting higher elastic response in combination with increasing of interaction between the ENR and the COPE phases.

Thermoplastic Natural Rubber of Co-Polyamide: Effect of Blend Ratios on Mechanical, Swelling, Dynamic and Morphological Properties

2013 ◽  
Vol 844 ◽  
pp. 89-92
Author(s):  
Boripat Sripornsawat ◽  
Azizon Kaesaman ◽  
Charoen Nakason
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Complex Viscosity ◽  
Continuous Phase ◽  
Morphological Properties ◽  
Elongation At Break ◽  
Degree Of Swelling ◽  
Tan Δ ◽  
Thermoplastic Natural Rubber ◽  
Blend Ratios

Maleated natural rubber (MNR) was synthesized and formulated to prepare thermoplastic natural rubber (TPNR) by blending with co-polyamide (COPA). It was found that 100% modulus, tensile strength, elongation at break, hardness and degree of swelling increased with increasing proportion of COPA. However, degree of swelling and tension set value decreased which reflects enhancing of rubber elasticity. Dynamic properties were also determined by a rotor less oscillating shear rheometer (Rheo Tech MDpt). It was found that increasing proportion of MNR caused increasing of storage modulus and complex viscosity but decreasing tan δ value. Morphological properties were also determined by SEM technique. It was found that the MNR/COPA simple blends with the proportion of rubber 40, 50 and 60 wt% exhibited the co-continuous phase structures.

Thermal Properties and Crystallisation Behaviour of Thermoplastic Natural Rubber (TPNR) Nanocomposites

2013 ◽  
Vol 812 ◽  
pp. 125-130 ◽  
Author(s):  
Siti Norasmah Surip ◽  
Z.Y. Zhang ◽  
H.N. Dhakal ◽  
N.N. Bonnia ◽  
S. H. Ahmad
Keyword(s):  
Thermal Properties ◽  
Natural Rubber ◽  
Nucleating Agent ◽  
Preparation Technique ◽  
Preparation Methods ◽  
Blending Method ◽  
Liquid Natural Rubber ◽  
Tan Δ ◽  
Thermoplastic Natural Rubber ◽  
Internal Mixer

The effect of preparation technique on the crystallisation behavior and thermal properties of TPNR filled nanoclay nanocomposites was investigated. The nanocomposites were prepared via melt blending method using internal mixer (Haake 600P). Two types of nanocomposites preparation technique were employed which is method A and B. In method A, the nanoclay was pre-mixed with liquid natural rubber (LNR) before it was charged into the other materials. For method B, the nanoclay was directly charged into the molten TPNR matrix. The result shows, preparation methods were significantly affect the crystallinity and thermal properties of TPNR nanocomposites. DSC thermogram revealed that nanocomposites crystallinity was increased when prepared by method A but decreased with method B. An increment in polypropylene crystallinity was attributed by the nanoclay which is believed to be as a nucleating agent. DMA thermogram suggested that the preparation method has affected the storage modulus and tan δ but not the glass transition temperature (tg).

Dynamically Cured Co-Polyester/Epoxidized Natural Rubber Blends: Influence of Epoxide Contents

2013 ◽  
Vol 844 ◽  
pp. 135-139
Author(s):  
Krisna Sasdipan ◽  
Azizon Kaesaman ◽  
Norbert Vennemann ◽  
Charoen Nakason
Keyword(s):  
Natural Rubber ◽  
Complex Viscosity ◽  
Decomposition Temperature ◽  
Epoxidized Natural Rubber ◽  
Elongation At Break ◽  
Rubber Blends ◽  
Thermoplastic Vulcanizates ◽  
Before And After ◽  
Rubber Phase ◽  
Tan Δ

Thermoplastic vulcanizates based on co-polyester and epoxidized natural rubber blends with various epoxide contents (i.e., 10, 20, 30, 40 and 50 mol% epoxide) were prepared. It was found that storage modulus and complex viscosity increased with increasing epoxide contents while tan δ decreased. Furthermore, increasing of glass transition temperature (Tg) of the rubber phase in the blend was observed with increasing epoxide content. Also, the tensile strength and elongation at break before and after aging increased with increasing epoxide content. Moreover, it was found that the epoxide content did not pragmatically effect on decomposition temperature (Td) of the blends, but it caused decreasing in decompositionrate of the blends.

Thermoplastic Natural Rubber Based on Blending of Co-Polyester: Effect of Amount of Epoxide Groups in Epoxidized Natural Rubber on Preperties

2012 ◽  
Vol 626 ◽  
pp. 50-53 ◽  
Author(s):  
Krisna Sasdipan ◽  
Azizon Kaesaman ◽  
Charoen Nakason
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Storage Modulus ◽  
Complex Viscosity ◽  
Epoxidized Natural Rubber ◽  
Dynamic Vulcanization ◽  
Elongation At Break ◽  
Vulcanized Rubber ◽  
Thermoplastic Matrix ◽  
Thermoplastic Natural Rubber

TPNRs based on blending of co-polyester (i.e., PBT/PC) and epoxidized natural rubber (ENR) with various epoxide content (i.e., 10, 20, 30, 40 and 50 mol% epoxide) were prepared by dynamic vulcanization. It was found that the co-polyester/ENR blends gave better properties (i.e., mechanical, dynamic mechanical, morphological and oil resistant properties) than that of co-polyester/unmodified NR blend. It was also found that co-polyester/ENR with 50 mol% epoxide exhibited the highest tensile strength, elongation at break, modulus at 100% elongation, hardness, storage modulus, complex viscosity and oil resistant properties but showed the lowest tension set value. This indicates the highest elasticity. Moreover, it was found that size of vulcanized rubber domains dispersed in thermoplastic matrix decreased with increasing the epoxide content in ENR molecules.

Toughness Enhancement of Polylactic Acid by Employing Glycolyzed Polylactic Acid-Cured Epoxidized Natural Rubber

2014 ◽  
Vol 1025-1026 ◽  
pp. 580-584 ◽  
Author(s):  
Phrutsadee Sukpuang ◽  
Mantana Opaprakasit ◽  
Atitsa Petchsuk ◽  
Pakorn Opaprakasit
Keyword(s):  
Natural Rubber ◽  
Polylactic Acid ◽  
Epoxidized Natural Rubber ◽  
Chemical Recycling ◽  
Crosslinking Reaction ◽  
Solvent Fractionation ◽  
Elongation At Break ◽  
Chemical Structures ◽  
Internal Mixer ◽  
Toughness Enhancement

Glycolyzed polylactic acid (GPLA)-cured epoxidized natural rubber (ENR) is developed for use as a toughening agent for PLA resin. GPLA is obtained from chemical recycling of PLA resin by a glycolysis reaction. GPLA-cured ENR is then prepared by the crosslinking reaction of ENR with GPLA in an internal mixer. Chemical structures of the cured products are characterized by solvent fractionation and thermogravimetric analysis (TGA). The cured ENR products are blended with PLA resin, by varying the cured ENR contents from 5 to 15% wt. Mechanical properties of the blends, and their toughening mechanisms are examined. The cured ENR materials has higher efficiency in improving toughness of PLA resin, compared to uncured ENR, likely due to their rubbery network nature and higher compatibility with the PLA matrix. The incorporation of 5% wt. GPLA-cured ENR also improves elongation at break with no adverse effect on tensile strength and modulus of PLA.

Improvement of Mechanical Properties and Water Absorption in Wheat Gluten by Epoxidized Natural Rubber

2019 ◽  
Vol 891 ◽  
pp. 163-168
Author(s):  
Kantima Chaochanchaikul
Keyword(s):  
Natural Rubber ◽  
Water Absorption ◽  
Thermal Analyses ◽  
Wheat Gluten ◽  
Research Work ◽  
Decomposition Temperature ◽  
Epoxidized Natural Rubber ◽  
Elongation At Break ◽  
Opposite Behavior ◽  
Internal Mixer

TThe aims of this research work were to improve touhgness and water resistance of wheat gluten (WG) by epoxidized natural rubber (ENR) compared to glycerol. WG specimens were mixed and prepared by internal mixer and compression molding machine, respectively. ENR and glycerol were varied from 10 to 40 wt%. Effects of modifier types and contents on WG were evaluated by tensile, impact and water absorption testings and microstructure and thermal analyses. The increase of ENR or glycerol contents led to the increase of toughness by considering the increase of impact strength and elongation at break. Glass transition temperature of WG tended to decrease with the increase of ENR or glycerol contents, especially for glycerol. The presence of glycerol affected to the decomposition temperature values whereas ENR did not affect to decomposition. ENR improved water resistant of WG specimen but trend of glycerol showed the opposite behavior. Weight loss of modified WG with glycerol was found at immersion time of 1440 min.

BETTER BALANCE OF SILICA-REINFORCED NATURAL RUBBER TIRE TREAD COMPOUND PROPERTIES BY THE USE OF MONTMORILLONITE WITH OPTIMUM SURFACE MODIFIER CONTENT

2020 ◽  
pp. 000-000 ◽  
Author(s):  
Mohammad Irfan Fathurrohman ◽  
Supagorn Rugmai ◽  
Nabil Hayeemasae ◽  
Kannika Sahakaro
Keyword(s):  
Natural Rubber ◽  
Abrasion Resistance ◽  
Dynamic Properties ◽  
Rolling Resistance ◽  
Complex Viscosity ◽  
Dynamic Mechanical Properties ◽  
Rubber Matrix ◽  
Dispersing Agent ◽  
Truck Tire ◽  
Key Factor

ABSTRACT Reinforcement of silica in tire tread compounds is known to reduce hysteresis or energy loss, which leads to a production of energy-saving tires. Even though silica–silane technology has been well established, further development to enhance its performance is still needed. One of the approaches is to use hybrid or dual filler. The use of silica-organomodified montmorillonite (MMT) dual filler in the reinforcement of natural rubber (NR) truck tire tread compounds is investigated. The NR-MMT master batches were prepared by using the in situ organomodified and latex compounding method. Because the surface-modifying agent or surfactant is a key factor in determining the level of MMT dispersion in the rubber matrix, the effect of quaternary amine salt (Q) contents on mechanical and dynamic properties of NR tread compounds reinforced by silica-MMT was studied. The results revealed that MMT and Q can effectively reduce the filler–filler interaction and complex viscosity owing to a good dispersion of MMT and silica in the NR matrix and Q, which acts as a dispersing agent in addition to the silane coupling agent used in the compound, leading to improvement in tensile, abrasion resistance, and dynamic mechanical properties with an increasing amount of Q. Furthermore, at the optimum content of the surfactant used (36 wt%), the silica-MMT–reinforced NR exhibited improved tensile strength (+4%), wet grip, and rolling resistance, respectively, as indicated by loss tangent at 0 °C (+6%) and 60 °C (−15%), while maintaining a modulus at 300% strain and abrasion resistance as compared with the silica-NR reference compound. Such a dual-filler system demonstrates its potential use for tire treads with better performance.

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.

Effect of Curing System on Morphological, Rheological, Thermal and Mechanical Properties of Thermoplastic Vulcanizates Based on Epoxidized Natural Rubber and Polypropylene

2012 ◽  
Vol 602-604 ◽  
pp. 690-695
Author(s):  
Hua Dong Wang ◽  
Rui Wang ◽  
Mao Fang Huang ◽  
Qi Yang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Epoxidized Natural Rubber ◽  
Thermal And Mechanical Properties ◽  
Rheological Analysis ◽  
Elongation At Break ◽  
Thermoplastic Vulcanizates ◽  
Internal Mixer

Thermoplastic vulcanizates (TPVs) based on epoxidized natural rubber (ENR) and polypropylene (PP) were prepared in an internal mixer at 180°C. The effects of curing systems (i.e., sulfur and peroxide) on morphological, rheological, thermal and mechanical properties were studied. It is found that the sulfur cured TPVs show higher tensile strength, tear strength and elongation at break than those cured with the DCP systems. The rheological analysis indicates that TPVs cured with DCP system show lower apparent shear viscosity than those with sulfur system. SEM studies show that TPVs vulcanized with DCP system exhibit smaller and finely dispersed rubber domains, which provides it higher thermal stability than sulfur cured TPVs.

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