starting formula for XNBR

1. Carboxylated Nitrile Rubber
XNBR - Uses & Applications
Based on a Paper presented at the
8th Brazilian Rubber Congress
XNBR - Uses & Applications

2. • V- belts
• High abrasion resistance shoes
• O-rings
• Printing rolls
• Rice dehusking rolls
• Oil extraction industry artifacts
• several technical goods...
XNBR - Uses & Applications
XNBR - Uses &Applications

3. The insertion of an acidic group gives the rubber
special properties
• Extra crosslinking
• Better tensile properties
• Higher continuous service temperature
• Chemical resistance
XNBR - Uses & Applications
XNBR - Carboxyl Group &
Special Properties

4. XNBR - Uses & Applications
XNBR - Carboxylated Nitrile Rubber
• Scorch safety - Rheometric Properties
ASTM formulation
Properties Results
ML (kgf/cm2
) 7,9
MH (kgf/cm2
) 38,4
Ts1 (min) 2,8
T90 (min) 18,0
Component phr
NITRICLEAN 3350X 100,0
HAF 330 carbon black 40,0
Zinc oxide 3,0
Stearic acid 1,0
Sulfur 1,5
TBBS 0,7
• Sulfur vulcanization
• Compounding according to
conventional NBR procedure

5. XNBR - Uses & Applications
XNBR versus NBR
Property Traditional NBR XNBR
Hardness Shore A 72 80
Tensile strenght (kgf/cm2
) 269 231
Elongation (%) 490 338
Modulus @ 300% (kgf/cm2
) 130 201
Compression set(%)
@ 22h, 100°C
57,6 36,9
• Compound analysis according to ASTM standard
• It is possible to infer that the raw rubber hardness for XNBR is higher than
conventional NBR hardness..
• Same butadiene content - Carboxyl group effect
• Advantage for conventional NBR in physical properties, HOWEVER, the
comparison is not valid due to the difference between the hardnesses of both
compounds.
XNBR = NITRICLEAN 3350X; NBR = N615B

6. XNBR Property Analysis
XNBR - Uses & Applications
Component Supplier phr phr
NITRICLEAN 3350X NITRIFLEX 100.0
N-615B NITRIFLEX 100.0
Zinc oxide RIO METALÚRGICA 5.0 5.0
Stearic acid CIA PARANAENSE 0.5 0.5
Antioxidant (BANNOX H) BANN QUÍMICA 1.5 1.5
SANTOFLEX IPPD FLEXSYS 1.5 1.5
Tackfier (UNILENE A-80) UNIPAR 1.0 1.0
Calcium carbonate QUIMBARRA 10.0 90.0
Silica DEGUSSA 20.0 30.0
DOP IPIRANGA 12.0 12.0
Sulfur AKROCHEM 1.5 1.5
CBS BANN QUÍMICA 0.5 0.5
TMTM BANN QUÍMICA 1.5 1.5
Rice dehusking roll formulation

7. XNBR Property Analysis
XNBR - Uses & Applications
• Comparative basis compound analysis
• NBR - Necessary to correct formulation compound to get to the
hardness of the XNBR compound
• Use of fillers (calcium carbonate & silica) -
Property NITRICLEAN 3350X N-615B
Hardness Shore A 67 67
Tensile strength (kgf/cm.cm) 149 103
Modulus @ 300% (kgf/cm.cm) 32 5
Abrasion (loss in mm3
) 33,5 158
Density (g/cm3
) 1,181 1,439
Tear strength (kgf/cm.cm) 29 18
Compression set(%, 22h @ 100°C) 57,2 65,6

8. Important Topics
• Necessity of insertion of fillers - higher density and loss
of properties
• XNBR - outstanding performance.
• Low density + high hardness of raw polymer
• Good abrasion resistance
• Compression set - points to a higher crosslinking ratio
• Good Tear resistance
XNBR Property Analysis
XNBR - Uses & Applications

9. Modification of traditional NBR with the insertion of
acidic groups - good performance of properties plus
distinct advantages:
• Better tensile properties
• Higher continuous service temperature
• Very good hardness/density balance
• Alternative to traditional NBR in harsher application
conditions
• Wide range of application in technical artifacts
XNBR - Summary
XNBR - Uses & Applications