2.2.2. Preparation of rubber–rubber joint for 180
◦
peel test
Preshaped, partially cured NR sheet was prepared in a hydraulic
press (David Bridge, Castleton, England) at 100
C using 5 MPa pressure.
A 2-min cure time was provided for the same purpose. The
surface modified EPDM vulcanized rubber sample of 1.5 mmthickness
was kept into the 3 mmmold cavity having an aluminium foil
of 20 mm width on its upper portion. The Al-foil was given to produce
a jaw for peel strength measurement. The preshaped uncured
NR was placed over the modified vulcanized EPDM rubber sample.
The whole assembly was incorporated into the hot molded press
at a temperature of 150
◦
◦
C and a pressure of 5 MPa till curing of
the uncured NR was completed. Additional 8 min cure time was
provided for the same because optimum cure of NR was 10 min, as
measured from a Monsanto rheometer. During conversion of partially
cured NR to completely cured NR, adhesion joint between
the modified EPDM vulcanized rubber and the NR was formed. One