scholarly journals The Physical Modification of a Natural Rubber-Polypropylene Thermoplastic Elastomer Blend by Azobisformamide Blowing Agent

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Safia Merabet ◽  
Farid Riahi ◽  
Abdelmalek Douibi
Keyword(s):  
Natural Rubber ◽  
Thermoplastic Elastomer ◽  
Decomposition Reaction ◽  
Major Effect ◽  
Crosslinking Reaction ◽  
Dynamic Vulcanization ◽  
Chemical Action ◽  
Blowing Agent ◽  
Thermoplastic Natural Rubber ◽  
Second Peak

The decomposition of azobisformamide (ABFA) blowing agent and its expansion in a soft grade of thermoplastic natural rubber composed of a 70/30 natural rubber (NR)/polypropylene (PP) was monitored using a Haake plasticorder. The aim of the study was to evaluate the effect of different concentrations of the blowing agent and to investigate its eventual interactions with a sulfur-based curing system that was used for the dynamic vulcanization. The plastograms allowed to detect variations in the initial mixing torque as well as the level of the final equilibrium torque for both unvulcanized and dynamically vulcanized blends. The plastograms of the dynamically vulcanized blends were characterized by the appearance of a second peak that corresponds to the crosslinking reaction which followed the blowing agent decomposition reaction. Since changing the order of the addition of the curatives with respect to the blowing agent did not cause any major effect on the general trend of the plastograms, it was concluded that the azobisformamide blowing agent did not alter the chemical action of the curatives and vice versa. The effects on the plastograms caused by variations in the blowing agent concentration were also reflected through the density measurements.

Effect of Antioxidant on Properties of Thermoplastic Natural Rubber Based on ENR/TPU Blends

2012 ◽  
Vol 626 ◽  
pp. 229-232 ◽  
Author(s):  
Ekwipoo Kalkornsurapranee ◽  
Charoen Nakason ◽  
Claudia Kummerlöwe ◽  
Norbert Vennemann
Keyword(s):  
Thermal Properties ◽  
Natural Rubber ◽  
High Performance ◽  
Thermoplastic Polyurethane ◽  
Oxidative Degradation ◽  
The Novel ◽  
Dynamic Vulcanization ◽  
High Elasticity ◽  
Thermoplastic Natural Rubber ◽  
Temperature Scanning

Thermoplastic natural rubber based on epoxidized natural rubber (ENR) and thermoplastic polyurethane (TPU) blend was prepared via dynamic vulcanization process. The main objective is to improve thermal properties of the blends. Two types of antioxidant: phenolic antioxidant (Wingstay®L) and N-(1,3-dimethzlbutyl)-N-Phenyl-p-phenylenediamine (6PPD) were used to improve oxidative degradation of the blends. It was found that thermal properties in term of thermal elastic properties and thermal stability can be improved by adding the antioxidants and 6PPD gave the blend with the highest thermal properties. These were measured based on temperature scanning stress relaxation (TSSR) technique. Incorporation of ENR into the TPU caused reduction of the hardness, improved thermal properties, elasticity and oil resistance compared to the neat TPU. These results indicated that the novel high performance TPNRs with high elasticity can be prepared.

Properties of Thermoplastic Natural Rubber (TPNR): Influence of Polypropylene Grades on TPNR Properties

2013 ◽  
Vol 844 ◽  
pp. 127-130 ◽  
Author(s):  
Chanida Manleh ◽  
Charoen Nakason ◽  
Natinee Lopattananon ◽  
Azizon Kaesaman
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Rubber Particle ◽  
Complex Viscosity ◽  
Morphological Properties ◽  
Dynamic Vulcanization ◽  
Thermoplastic Natural Rubber ◽  
Pp Blends ◽  
Vulcanization Process

Thermoplastic vulcanizate (TPV) based on natural rubber (NR) and polypropylene (PP) blends were successfully prepared through a dynamic vulcanization process using Brabender Plastograph EC Plus with a rotor speed of 60 rpm at 180°C. Sulfur vulcanization system was used to cure rubber phase in the TPVs. Three grades of PP (i.e., PP700J, HP553R and HP544T) were used to blend with NR at a fixed blend ratio of NR/PP = 60/40. The mechanical properties, crosslink density, complex viscosity and morphological properties of the blends were examined. The results revealed that the dynamically cured NR/PP700J samples showed the best mechanical properties because of higher crosslink density and smaller rubber particle size when compared with those of the blends combined with HP553R and HP544T. Furthermore, the complex viscosity of the TPVs was highest for the blends with PP700J.

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.

Partially Dynamically Vulcanized Thermoplastic Elastomer Based on Natural Rubber-Polypropylene-Clay Nanocomposites

2013 ◽  
Vol 747 ◽  
pp. 230-233 ◽  
Author(s):  
Natinee Lopattananon ◽  
Supattra Tanglakwaraskul ◽  
Azizon Kaesaman ◽  
Manus Seadan ◽  
Tadamoto Sakai
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Thermoplastic Elastomer ◽  
Optimal Level ◽  
Continuous Phase ◽  
Clay Nanocomposites ◽  
Dynamic Vulcanization ◽  
Elongation At Break ◽  
Pp Blends ◽  
Strength Improvement

Thermoplastic vulcanizate (TPV) nanocomposites based on 60/40 (%wt) natural rubber (NR)/polypropylene (PP) blends were prepared by dynamic vulcanization. Sodium montmorillonite (Na-MMT) was use as a filler to improve TPV properties. The addition effect of Na-MMT on the TPV properties was examined. The results indicated that the blend exhibited a co-continuous phase structure. The presence of clay in the NR phase decreased crosslinking level of NR, but improved mixing of NR and PP during dynamic vulcanization. The addition of clay marginally enhanced the 100% modulus and tensile strength, but decreased elongation at break due to more homogeneous blend morphology. The optimal level of tensile strength improvement was obtained when loading of clay was 5 phr. The permanent set of the blends did not changed significantly with the clay dispersion. The storage modulus and resistance to oil and heat improved with incorporation of clay, proportional to clay loading.

Investigation of Structure-Properties Relationship of High Performance TPV Based on ENR/TPU

2013 ◽  
Vol 844 ◽  
pp. 113-116 ◽  
Author(s):  
Ekwipoo Kalkornsurapranee ◽  
Charoen Nakason ◽  
Skulrat Pichaiyut ◽  
Claudia Kummerlöwe ◽  
Norbert Vennemann
Keyword(s):  
Natural Rubber ◽  
Functional Groups ◽  
High Performance ◽  
Grain Morphology ◽  
Morphological Properties ◽  
Dynamic Vulcanization ◽  
Thermoplastic Natural Rubber ◽  
Polar Functional Groups ◽  
Relationship Of ◽  
Structure Properties

Thermoplastic natural rubber based on blending of ENR-50/TPU and un-modified NR/TPU was prepared via dynamic vulcanization technique. Influences types of natural rubber (i.e., un-modified NR and ENR-50) on mechanical and morphological properties of the blends were investigated. It was found that the blends with ENR-50 exhibited superior properties than that of the blend with unmodified NR. This is attributed to the interactions between the functional groups of ENR molecules and polar functional groups in TPU molecules which caused higher interfacial adhesion and interaction between both phases. The chemical interactions were confirmed by ATR-FTIR. Furthermore, it was found that the ENR-50/TPU blend showed smaller and finer grain morphology compared with the un-modified NR/TPU.

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.

Effect of carbon allotropes on foam formation, cure characteristics, mechanical and thermal properties of NRF/carbon composites

2020 ◽  
pp. 0021955X2097954
Author(s):  
Pollawat Charoeythornkhajhornchai ◽  
Wutthinun Khamloet ◽  
Pattharawun Nungjumnong
Keyword(s):  
Natural Rubber ◽  
Bubble Diameter ◽  
Carbon Composites ◽  
Mechanical And Thermal Properties ◽  
Foam Formation ◽  
Carbon Filler ◽  
Composite Foam ◽  
Carbon Allotropes ◽  
Blowing Agent ◽  
Rubber Composite

Natural rubber composite foam with carbon such as carbon black (CB), carbon synthesized from durian bark (CDB), graphite (GPT), graphene oxide (GO), graphene (GPE) and multi-walled carbon nanotubes (MWCNT) was studied in this work to investigate the relationship between foam formation during decomposition of chemical blowing agent mechanism and crosslink reaction of rubber molecules by sulphur. Natural rubber composite foam with carbon particle was set at 3 parts per hundred of rubber (phr) to observe the effect of carbon allotropes on foam formation with different microstructure and properties of natural rubber composite foam. The balancing of crosslink reaction by sulphur molecules during foam formation by the decomposition of chemical blowing agent affects the different morphology of natural rubber foam/carbon composites leading to the different mechanical and thermal properties. The result showed the fastest cure characteristics of natural rubber foam with 3 phr of graphene (NRF-GPE3) which was completely cure within 6.55 minutes (tc90) measured by moving die rheometer resulting in the smallest bubble diameter among other formulas. Moreover, natural rubber foam with 3 phr of MWCNT (NRF-MWCNT3) had the highest modulus (0.0035 ± 0.0005 N/m2) due to the small bubble size with high bulk density. In addition, natural rubber foam with 3 phr of GPT (NRF-GPT3) had the highest thermal expansion coefficient (282.12 ± 69 ppm/K) due to high amount of gas bubbles inside natural rubber foam matrix and natural rubber foam with 3 phr of GO (NRF-GO3) displayed the lowest thermal conductivity (0.0798 ± 0.0003 W/m.K) which was lower value than natural rubber foam without carbon filler (NRF). This might be caused by the effect of bubble diameter and bulk density as well as the defect on surface of graphene oxide compared to others carbon filler.

scholarly journals Composites from Thermoplastic Natural Rubber Reinforced Rubberwood Sawdust: Effects of Sawdust Size and Content on Thermal, Physical, and Mechanical Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Chatree Homkhiew ◽  
Surasit Rawangwong ◽  
Worapong Boonchouytan ◽  
Wiriya Thongruang ◽  
Thanate Ratanawilai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
High Density Polyethylene ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
Modulus Of Rupture ◽  
Shore Hardness ◽  
Thermoplastic Natural Rubber ◽  
Plastic Content

The aim of this work is to investigate the effects of rubberwood sawdust (RWS) size and content as well as the ratio of natural rubber (NR)/high-density polyethylene (HDPE) blend on properties of RWS reinforced thermoplastic natural rubber (TPNR) composites. The addition of RWS about 30–50 wt% improved the modulus of the rupture and tensile strength of TPNR composites blending with NR/HDPE ratios of 60/40 and 50/50. TPNR composites reinforced with RWS 80 mesh yielded better tensile strength and modulus of rupture than the composites with RWS 40 mesh. The TPNR/RWS composites with larger HDPE content gave higher tensile, flexural, and Shore hardness properties and thermal stability as well as lower water absorption. The TPNR/RWS composites with larger plastic content were therefore suggested for applications requiring high performance of thermal, physical, and mechanical properties.

Effect of Blowing Agent on Cell Morphology and Acoustic Absorption of Natural Rubber Foam

2015 ◽  
Vol 804 ◽  
pp. 25-29 ◽  
Author(s):  
Wanlop Harnnarongchai ◽  
Kantima Chaochanchaikul
Keyword(s):  
Natural Rubber ◽  
Cell Size ◽  
Cell Morphology ◽  
Foam Cell ◽  
Adsorption Coefficient ◽  
Low Frequencies ◽  
Potassium Oleate ◽  
High Frequencies ◽  
Blowing Agent ◽  
Open Cell Foam

The sound absorbing efficiency of natural rubber (NR) foam is affected by the cell morphology of foam. Potassium oleate (K-oleate) and sodium bicarbonate (NaHCO3) were used as blowing agents to create open-cell foam. Amounts of the blowing agent were varied from 0.5 to 8.0 part per hundred of rubber (phr) to evaluate cell size and number of foam cell as well as sound adsorption coefficient of NR foam. The NR foam specimens were prepared using mould and air-circulating oven for vulcanizing and foaming processes. The results indicated that K-oleate at 2.0 phr and NaHCO3 at 0.5 phr led to form NR foam with the smallest cell size and the largest number of foam cell. At low frequencies, the optimum sound adsorption coefficient of NR foam was caused by filling K-oleate 2 phr. However, that of NR foam at high frequencies was provided by 0.5 phr-NaHCO3 addition.

Sign in / Sign up

Export Citation Format

Share Document