Silica-Reinforced Natural Rubber with Epoxidized Low Molecular Weight Rubber as a Compatibilizer

2013 ◽  
Vol 747 ◽  
pp. 522-525 ◽  
Author(s):  
Prachid Saramolee ◽  
Kannika Sahakaro ◽  
Natinee Lopattananon ◽  
Wilma Dierkes ◽  
Jacques W.M. Noordermeer

This work investigates the effect of epoxidized low molecular weight natural rubber (ELMWNR) in silica-filled NR compounds on processing, mechanical and dynamic mechanical properties. The ELMWNRs with mol% epoxide groups varying from 0-50 and molecular weight in a range of 50,000-60,000 g/mol were prepared from depolymerization of epoxidized natural rubber using periodic acid in latex state. They were then added in the silica-filled NR compounds as a compatibilizer at varying loading from 0-15 phr. The addition of ELMWNR decreases compound viscosity and Payne effect, i.e. filler-filler interaction. The optimal mechanical properties of silica-filled vulcanizates are observed at the ELMWNR-28 (28 mol% epoxide) loading of 10 phr. The incorporation of ELMWNR with 28 and 51 mol% epoxide groups into NR compounds introduces a second glass transition temperature and affects on their dynamic mechanical properties. Higher epoxide content leads to higher Tan δ of the rubber vulcanizates in the range of normal service temperature.

2014 ◽  
Vol 87 (2) ◽  
pp. 320-339 ◽  
Author(s):  
P. Saramolee ◽  
K. Sahakaro ◽  
N. Lopattananon ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer

ABSTRACT This work investigates the effect of epoxidized low molecular weight natural rubber (ELMWNR) in silica- and carbon black-filled natural rubber (NR) compounds on processing and mechanical and dynamic mechanical properties. The ELMWNRs with different mol% epoxide content were prepared from depolymerization of epoxidized NR using periodic acid in latex state to have a molecular weight in a range of 50 000–60 000 g/mol. Their chemical structures and actual mol% of epoxide were analyzed by 1H NMR. The ELMWNRs were added to the filled NR compounds as compatibilizers at varying loadings from 0 to 15 phr. The addition of ELMWNR decreases compound viscosity and the Payne effect, that is, filler–filler interaction, of the silica-filled compound. In the silica–silane compound and the compound with 28 mol% epoxide (ELMWNR-28), the compound viscosities are comparable. The optimal mechanical properties of silica-filled vulcanizates are obtained at the ELMWNR-28 loading of 10 phr. In contrast, the addition of ELMWNR to a carbon black-filled compound shows only a plasticizing effect. The incorporation of ELMWNR into NR compounds introduces a second glass transition temperature and affects their dynamic mechanical properties. Higher epoxide contents lead to higher loss tangent values of the rubber vulcanizates in the range of the normal service temperature of a tire.


2013 ◽  
Vol 844 ◽  
pp. 305-308
Author(s):  
Zhong Xian Ooi ◽  
Hanafi Ismail ◽  
Azhar Abu Bakar

The potential of utilizing low cost filler, i.e. oil palm ash (OPA) as a new filler in natural rubber (NR) compounds using conventional laboratory-sized two roll mills. The NR compound was cross-linked using sulphuric system. The variations of tensile and dynamic properties were examined in the NR vulcanizates with the OPA filling at low loading. In the view of reinforcement, the tensile strength and elongation at break was improved with the low loading of OPA (<10 phr). Dynamic mechanical properties of OPA filled NR vulcanizates was investigated with respect to the storage modulus and mechanical loss factor (Tan δ). Result showed that the storage modulus of the OPA filled NR vulcanizates became higher than that of gum NR vulcanizates whereas the peak height of tan δmax was reduced as the OPA loading was increased. This phenomenon manifested a strong rubber-filler interaction with the low loading of OPA.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
T. A. Dung ◽  
N. T. Nhan ◽  
N. T. Thuong ◽  
D. Q. Viet ◽  
N. H. Tung ◽  
...  

The dynamic mechanical behavior of modified deproteinized natural rubber (DPNR) prepared by graft copolymerization with various styrene contents was investigated at a wide range of temperatures. Graft copolymerization of styrene onto DPNR was performed in latex stage using tert-butyl hydroperoxide (TBHPO) and tetraethylene pentamine (TEPA) as redox initiator. The mechanical properties were measured by tensile test and the viscoelastic properties of the resulting graft copolymers at wide range of temperature and frequency were investigated. It was found that the tensile strength depends on the grafted polystyrene; meanwhile the dynamic mechanical properties of the modification of DPNR meaningfully improved with the increasing of both homopolystyrene and grafted polystyrene compared to DPNR. The dynamic mechanical properties of graft copolymer over a large time scale were studied by constructing the master curves. The value of bT has been used to prove the energetic and entropic elasticity of the graft copolymer.


2014 ◽  
Vol 925 ◽  
pp. 308-312 ◽  
Author(s):  
Mou'ad A. Tarawneh ◽  
Sahrim Haji Ahmad ◽  
Yu Li Jiun ◽  
Radwan Dweiri ◽  
Ibrahim N. Hassan

In this paper the polymer nanocomposite of nickel zinc (NiZn) ferrite nanoparticles incorporated into the thermoplastic natural rubber nanocomposite (TPNR) were prepared via melt blending method. The effect of different NiZn loading (2-10 wt%) on morphology, tensile and dynamic mechanical properties of the obtained composites was investigated. It was found that NiZn ferrite is well dispersed in the thermoplastic natural rubber matrix. The tensile results indicated that filler loading has improved the tensile strength and Youngs modulus of the nanocomposite. However, the elongation at break decreased with increasing the percentage of NiZn. Dynamic mechanical test showed that the highest storage modulus is at 8 wt% filler. Any further increment of the filler content leads to the formation of agglomerate hence affecting the properties. The Scanning electron micrograph (SEM) micrographs reveal aspect ratio and filler orientation in the TPNR matrix also strongly promoted interfacial adhesion between the filler and the matrix to control its properties.


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