2. Preparation of dynamically cured DSNR/PP blends
The DSNR was first compounded using a formulation and step of mixing, as shown in Table 1. A Brabender
Plasticoder with a rotor speed of 60 rpm and 40
o
C was exploited. The dynamically cured 60/40 DSNR/PP blend with
various type of vulcanization (i.e., sulphur, phenolic, peroxide and mixed sulphur-peroxide) were prepared via dynamic
vulcanization during melt mixing at 180
o
C using a mixing schedule, as shown in Table 2.
Table 1
Compounding formulation and step of mixing
Ingredient
Quantities (phr)
Time of mixing
(min)
Phenolic
Sulphur
Peroxide
Sulphur / Peroxide
DSNR
100
100
100
100
2
ZnO
5
5
5
5
1
Stearic acid
1
1
1
1
1
Wingstay L
1
1
1
1
1
DCP
-
-
2
1
1
TAC
-
-
1
0.5
1
SnCl
2
.2H
2
O
0.6
-
-
-
1
HRJ-10518
5
-
-
-
1
Sulphur
-
2.5
-
1
1
Table 2
Mixing schedule for dynamically cured DSNR/PP blend
Description
Time(min)
Mix PP
5
Blend compatibilizer
2
DSNR compound
Until plateau mixing torque
3. Machanical properties
The dumbbell-shaped specimens with 2 mm thick were prepared by a thermoplastic iniection-molding
machine (Welltec Machinery Ltd., Hong Kong). Stress-strain behaviors of the TPVs based on dynamically cured
DSNR/PP blends were characterized at 25 ± 2
o
C at a crosshead speed of 500 mm min
-1
. The instrument used was a
Hounsfield Tensometer, (model H 10 KS manufactured by the Hounsfield Test Equipment Co., Ltd., UK). Aging
properties of the TPVs were also investigated according to ASTM D573.
4. Dynamic properties
Storage modulus, complex modulus, tan
δ
and complex viscosity of the dynamically cured DSNR/PP
blends were characterized using a rubber process analyze (RheoTech MDPT, Cuyahoya Falls, USA) at 180
o
C. The
oscillation frequency was set in the range of 1-15 Hz at a constant strain of 3%.
