2 high temperature, and the process is known as dynamic vulcanization. Dynamic
vulcanization of epoxidized natural rubber ENR and polypropylene PP are also performed by using either a sulfur based system or peroxide. The sulfur cured
system showed superior mechanical properties in term of tensile strength, elongation at break and tension set compared to the peroxide system due to the polypropylene
degradation during dynamic vulcanization.
1.2 Problem Statement
Polypropylene PP is well-known of its outstanding dielectric properties under high voltage and high frequency condition up to 30 kHz Khachen et al., 1992. Due to
that, it is a suitable material for electrical insulator whether in interior or exterior cables. However, PP is less flexible when the thickness of the cable is increases. The
epoxidized natural rubber ENR is a potential candidate to increase the flexibility of polypropylene. Malaysia is known as the world’s major natural rubber producer.
ENR being a derivative of natural rubber is more readily available, and it has unique properties offering high strength due to their ability to undergo strain crystallization,
along with increased glass transition temperatures and solubility parameter. These properties are reflected in vulcanizates with increased oil resistance, enhanced
adhesive properties, high degree of damping and reduce gas permeation Gelling, 1991. Response surface methodology RSM is reported to be an effective tool for
optimizing a process, as highlighted by various workers Yadav et al., 2007. RSM could save cost and time by reducing number of experiments required. The
application of RSM to design optimization is aimed at reducing the cost of expensive analysis methods and their associated numerical noise. Originally, RSM
was developed to model experimental responses Box and Draper, 1987, and then migrated into the modeling of numerical experiments.
3
1.3 Objective
The main objectives on this research are:
i. To produce PPENR blend via melt blending using internal mixer.
ii. To determine the optimum formula and mixer parameter using response surface methodology
iii. To characterize the properties of PPENR blend through testing and analysis.
1.4 Scope
This research is focusing on optimization of formulation and mixer parameter to produce PPENR blend. Firstly, the experiment was designed using RSM. Then,
samples were prepared in different combination of process parameters in an internal mixer followed by various physical and mechanical testing. Some analysis such as
thermal and morphology were performed to support the data.
1.5 Chapter Overview
