DEVELOPMENT OF O-RING BY USING PER-OXIDE CURING
Made by,
Mohammad Sameer Ghazi PP-005
Muhammad Anwer PP-011
Ahad Aslam Ghulam Hussain PP-029
S.M. Jasir Ahsan PP-036
Objective of Project
To develop a product via peroxide curing of specialty elastomer and achieve a material having low compression set
and high heat resistance.
Special Purpose Elastomers
Those elastomers that poses superior properties compared to general purpose elastomers, we call them specialty elastomer.
Some examples are:
• Silicon Rubber (inert, high service temperature)
• EPDM (air permeabiltiy, resistance to heat, ozone
resistance)
• HNBR (oil resistance, low compression set, high heat
resistance)
Choosing HNBR
HNBR derived from NBR showed better performance than NBR due to its high saturation.
Comparison of HNBR, NBR & Fluoroelastomer
PROPERTIES FLOUOROCARBONRUBBER
NITRILERUBBER
HNBRRUBBER
Mechanical strength Excellent Good Good to Excellent
Oil resistance Excellent Good Good
Compression set Excellent Fair Good to Excellent
Cost Expensive Fair Fair
Low Temperature Flexibility
Excellent Good Good to Excellent
Processing Hard Moderate Moderate
Purpose behind implementing Peroxide
Curing for HNBR
Static Application
HNBR being Highly Saturated Rubber
Good Compression Set especially at elevated
temperature
High Temperature Resistance
Low Flexibility
What is Peroxide Curing
• Direct carbon crosslinks are formed between saturated elastomer molecule.
ROOR 2 RO·RO· + H-P ROH + P·P· + P· P-P
Factors of Selection of Peroxide Curing Agent
Processing Temperature (160◦C)
Participation of active oxygen in cross-linking
function (Efficiency).
Here Di-cumyl peroxide suits best as a curing
agent.
Why Di-Cumyl Peroxide?
Serve as high temperature catalyst
Less sensitive to environment
Better performance
Sample Preparation
MATERIALS CODE A-1 B-1 C-1 D-1 E-1 F-1 G-1
HNBR (PHR) 100 100 100 100 100 100 100
C. BLACK (N220)
505 56 56 56 60 52 60 52
SILICA 007 - - 12 12
Zn OXIDE 538 5 5 5 5 5 5 5
Anti Ox./Oz. 280 1 1 1 1 1 1 1
TOTAL PHR 162 162 162 166 170 166 170
DCP (PHR) 5 5 5 5 5 5 5
EDMA(PHR) 0 7.5 9.5 6 6 6 6
TOTAL PHR 171.5 179 181 181.5 185.5 181.5 185.5
Preparation of Master Batch
Preparation of Finish
Characterization of Sample
TimeTemperatur
e
15 Min160 ˚C
15 Min160 ˚C
15 Min160 ˚C
15 Min160 ˚C
15 Min160 ˚C
15 Min160 ˚C
15 Min160 ˚C
100 % modulus
18.63 24.55 24.3 27.18 22.32 - 23.23
Tensile (Psi) 32.5 30.57 32.24 27.18 32.28 24.41 28.73
Elongation (%)
144 121 128 103 133.3 93 118
Tear Resistance
28.4 27 32 26.3 32.7 - -
Hardness 75 78 77 75 77 76 79
Tensile (Psi) 32.5 30.57 32.24 27.18 32.28 24.41 28.73
Compression set (%)
24 27 27 16 19 21 16
Comparing Samples
A-1 B-1 C-1 D-1 E-1 F-1 G-10
5
10
15
20
25
30
35
Tensile Strength Psi
Elongation %
A-1 B-1 C-1 D-1 E-1 F-1 G-10
20
40
60
80
100
120
140
160
Comparing Samples
A-1 B-1 C-1 D-1 E-1 L-1 M-10.000
5.000
10.000
15.000
20.000
25.000
30.000Compression Set %
A-1 B-1 C-1 D-1 E-1 F-1 G-173
74
75
76
77
78
79
80Hardness Shore A
Future Work
FKM can be used as a substitute of HNBR with
better service temperature above 200ºC.
Different particle sizes of carbon black can be
used to improve compression set (%) and oil swell
properties.
Towards the End….
D1 showed optimum results but has less hardness and elongation compared to E1.
E1 showed best required properties, therefore considered to be our final product.
Finally making our product cost effective.