Studies on the use of nano zinc oxide and modified silica in NR, CR ...

Chapter 2
47
In a particular experiment, rubber from the same lot has been used.
This is because the molecular weight distribution and non-rubber constituents
of natural rubber are affected by clonal, seasonal variation and method of
preparation etc. 2
Chloroprene rubber
Chloroprene rubber (CR) with a Mooney viscosity ML (1+4), at 100°C
of 47 and specifications given in Table 2.2 was supplied by Toyo Soda Mfg
Co. Ltd, Tokyo.
Table 2.2 Specifications of CR
Sl. No. Parameters Limit
1. Viscosity Very low
2. Crystallization resistance poor
3. Peptizable poor
4. Extendable good
5. Stability excellent
Styrene butadiene rubber (SBR)
Styrene butadiene rubber used was SBR 1502 grade, obtained from
JSR Company, Japan. The Mooney viscosity (ML 1+4, 100°C) was 52. The
specifications are given below.
Table 2.3 Specifications of SBR
Volatile matter, % by mass 0.23
Ash, % by mass 0.24
Organic acid, % 5.53
Soap Traces
Bound Styrene, % by mass 24.00