Solid State Science and Technology, Vol. 20, No 1 & 2 (2012) 142-147

ISSN 0128-7389






Rohaidah Abd. Rahim*, Ahmad Khairul Muhamad and Mohd Ismail Rifdi Rizuan


Malaysian Rubber Board, Technology Centre, RRIM Research Station,

Sg. Buloh, 47000 Selangor, Malaysia

*Corresponding author:



Malaysian Rubber Board has developed a new grade of rubber using a new process and

technique for production of field coagulum grades. Research showed that the new

process natural rubber (NPR) has low gel content, better processability, low modulus

and similar recovery behaviour and physical properties compared to commercial

Standard Malaysian Rubber (SMR). Further research is carried out to determine the

dynamic properties of NPR by Dynamic Mechanical Thermal Analysis (DMTA) and

Gabo flexometer. The DMTA measures the tan delta values of material when exposed

to temperatures from -70°C to 80°C at constant deformation. The Gabo flexometer

machine can be used to determine heat build-up and viscoelastic properties of rubber

undergoing rapid cyclic deformations at certain frequency or over a range of

frequencies. The cyclic deformation behavior of rubber is important in products such as

an indication of tyre performance, bearing, v-belts, and cable pulley insert rings etc.

which are subjected to dynamic flexing in service. The dynamic properties of NPR are

compared with commercial grades SMR 10 and SMR CV 60. DMTA results show that

the vulcanizates give almost similar curves and values at both 0°C and 60°C indicating

little differences in the compound’s wet grip and rolling resistance properties for the

three grades of rubber. The Gabo flexometer machine determined heat build-up and

viscoelastic properties of rubber. The results indicate that the NPR generates the lowest

heat build-up value and low tan delta as compared to SMR 10 and SMR CV60. As a

general conclusion, NPR could be advantages as an alternative material for tyre



Keywords: DMTA; Gabo flexometer; heat build-up; viscoelastic properties; tan delta

En Shahril Idzulsyahril (DMTA and heat build-up test).



[1] M. Ahmad Khairul, K. Nur Hidayaty and M.N. Zairossani, Process

Improvement of DPNR Production: Exploratory Experiment of New DPNR

Enzymatic Process (2007)UPPC Internal Report No.71.

[2] ASTM D623-07.Standard Test Methods for Rubber Property – Heat generation

and flexing fatigue in compression.

[3] ISO 4666/3. Rubber vulcanised- Determination of temperature rise and

resistance to fatigue in flexometer testing. Part 3; Compression flexometer.