1. CRB 30204 RUBBER TECHNOLOGY – CHAPTER 1
Nurul Iman Abdul Razak

2. Chapter Outline
Types of rubbers and their application

3. Natural Rubber (NR)
From Hevea brasiliensis tree.
Structure:

4. NR Latex concentrate: Dry Rubber: Centrifuged latex
Creamed latex
Evaporated latex
Dry Rubber:
Ribbed Smoked Sheets (RSS)
Air-dried Sheets
Pale Crepes
*Conventional Grades

5. Technically Specified Rubbers (TSR)
TSR were first introduced into the market by Malaysia in 1965 as the Standard Malaysian Rubber (SMR).
SMR graded by:
source of the rubber
properties
There are:
SMR L
SMR CV
SMR GP
SMR 10,20 & etc.

6. SMR L light-coloured rubber from high quality of field latex
superior heat ageing resistance
excellent vulcanizate  properties
high TS, E & EB

7. Application
ideal choice for production of light-coloured / translucent products such as:
shoe soles
pressure-sensitive tapes
surgical and pharmaceutical products
industrial printing rollers
gaskets

8. SMR CV CV : constant viscosity
produced from high quality field latex, has a Mooney viscosity stabilized within a narrow range
generally softer than the non viscosity-stabilized grades, it increases the productive capacity of mixing equipment.

9. Application of SMR CV high quality products
mechanical mountings for engines and machinery
bridge bearings
vehicle suspension systems
large truck tire treads,
conveyor belt covers
cushion gum for tire retreading
masking tapes
injection molded products including rubber/metal bonded components
industrial rolls
rubber cements.
*It is frequently blended with other grades of NR to optimize cost and balance of other properties such as viscosity.

10. SMR GP: general purposes
Made from 60:40 mixture of latex-grade sheet rubber and field coagulum.
Dark colored rubber
Application:
Make it suitable for tire production
Plasticizer in SMR GP gives beneficial to tire manufacturers.

11. SMR 10
Produced from clean and fresh field coagulum of from sheets that have not been through the smoking process.
Application:
It can be used for tires
cushion gum stocks
joint rings by injection molding
microcellular sheets
for upholstery and packing
conveyor belts
footwear.

12. SMR 20 Application: It is produced mostly from field coagulum
Its low viscosity and easier mixing characteristic
Application:
It is used mostly for tires
cushion gum stock
bicycle tires
micro-cellular sheet for upholstery and packing
conveyor belts
footwear and other general products.

13. Other forms of natural rubber
Oil-extended Natural Rubber (OENR)
Deproteinised Natural Rubber (DPNR)
Peptised Rubber
Powdered Rubber
Superior Processing Rubbers (SP)
Heveaplas MG Rubbers (MG)
Epoxidized Natural Rubber (ENR)
Thermoplastic Natural Rubber (TPNR)

14. Product Applications Tyres
In passenger-car bias-ply tyres, NR is used only in the carcass as well as the side walls, where the hot tear resistance, adhesion and tack of NR are used to advantage.
In commercial vehicles, the amount of NR used increases with the size of the tyre. In large earthmover tyres, for example, almost 100% NR is used due to the requirements of low heat generation and high cutting resistance.
Natural rubber is used in blends with halobutyl rubbers in the inner liner tubeless tyres.

15. Mechanical Goods (Industrial Products)
This include a large variety of products such as hose, conveyor belts, rubber linings, gaskets, seals, rubber rolls, rubberized fabrics, etc.
In these products, the choice of elastomers is made on the best compromise between price and performance.

16. Engineering Products
The softness of a natural rubber component in different directions may be varied independently by the judicious use of shape effects.
In dynamic applications such as springs, and vibration mountings, bushings, and so forth, high fatigue resistance, good strength, and durability are additional points in favour of NR.
In other applications such as bridge bearing, factors such as weathering, ozone resistance, and low temperature flexibility are also important.
NR is now accepted as suitable for use in bridge bearings, in place of, neoprene.

17. Latex Goods
NR latex has now been largely replaced by polyurethane in foam for upholstery and bedding.
The main uses of latex are in dipped goods, foam, carpet backing, thread and adhesives.

18. Footwear
Natural rubber is extremely suitable for rubber footwear manufacturing. Its use is limited only by cost.

19. STYRENE-BUTADIENE RUBBERS (SBR)
Raw Materials
The chief raw materials required to manufacture SBR are butadiene and styrene.
Structure:

20. Application:
Elastomer SBR:
pneumatic tires
shoe heels and soles
gaskets
chewing gum
Emulsion SBR:
coated paper
as a sealing and binding agent behind render

21. BUTYL RUBBER Low rates of gas permeability. Thermal stability.
Ozone and weathering resistance.
Vibration damping and higher coefficients of friction, and
Chemical and moisture resistance.

22. Applications
Gas Permeability
A passage of gas is a function of the diffusion gas molecules through the membrane and the solubility of the gas
The Polyisobutylene of the butyl molecule provides a low degree of permeability
Butyl is at least 8 times better than NR in air retention.

23. air barriers for tubeless tires
air cushions
pneumatic springs
accumulator bags
air bellows

24. Ozone and Weathering Resistance
Ozone and weather resistance, the least unsaturated butyl is advantageously.
Preferred for electrical applications needing ozone resistance, and in rubber sheeting for roofs and water management systems.
High quality electrical insulation.

25. Vibration Damping
Automotive suspension bumpers.
More highly damped butyl compositions more effectively control vibrational forces.
In theory, more highly damped systems will less effectively isolate vibration at very high frequencies.
In practice, dynamic stiffness becomes a controlling factor governing transmissibility.

26. electrical insulation and rubber sheeting for outdoor use
Chemical and Moisture Resistance.
electrical insulation and rubber sheeting for outdoor use
elastomeric seals for hydraulic systems using synthetic fluids
After 13 weeks immersion in 70% sulfuric acid, a butyl compound experiences little loss in tensile strength or elongation. Under similar conditions, natural rubber or SBR will be highly degraded.

27. ETHYLENE PROPYLENE (EP) RUBBER
highly resistant to ozone and oxidation
excellent heat resistance and weatherability
have varying degrees of heat and oil resistance and elasticity;

28. Coolant hose (automotive)
Applications
Coolant hose (automotive)
Variety of industrial: air and water hose and for phosphate and ketone service.
Insulation in power cables and ignition wiring
Cable covers
Underground wire and connector
Coated fabrics and sheet goods
As viscosity modifiers in lubricating
Automotive: coolant hose for its excellent water and coolant resistance.
variety of industrial: air and water hose and for phosphate and ketone service.
insulation in power cables and ignition wiring
cable covers where abrasion and heat but not oil resistance is required.
underground wire and connector due to its water resistance.
coated fabrics and sheet goods where the largest volume goes into moisture barriers and one-ply roofing.
as viscosity modifiers in lubricating oil to improve low temperature impact strength of PE and PP.

29. NITRILE RUBBERS (NBR)
Nitrile rubbers basically are manufactured by emulsion copolymerization of butadiene with acrylonitrile in process similar to SBR.
The basic reaction is as follows:

30. good resistance towards nonpolar oils, fats, and solvents.
Application
good resistance towards nonpolar oils, fats, and solvents.
used in automotive and oil industry like oil seals and automotive hydraulic hose.
better heat resistance than CR but they are subject to ozone cracking

31. CHLOROPRENE RUBBERS also known as neoprene
resistance towards a wide variety of animals and vegetables fats and oils, waxes, and greases and also aliphatic hydrocarbons.
good resistance to ozone attack, air oxidation, or weathering
ability to retard flame,
have tendency to self extinguish when flame source is removed.
has high level of resistance to flex cracking.

32. Application:
used for hose,
belts,
wire and cable covering,
coatings,
sheeting and adhesives

33. CHLOROSULPHONATED POLYETHYLENE RUBBERS, CSM
CSM is obtained by reacting polyethylene in solution with chlorine and sulfur dioxide.
Structure:

34. comparable with chloroprene rubber but it has better resistance to acids, solvent, ozone, oxidation and better color stability.
very good resistance towards flex and abrasion, excellent resistance to oxidation aging, weathering, acids and alkali, and moderate resistance to oil and gasoline.
poor resistance to aromatic solvent, flexibility at low temperature is limited and moderate compression set and resilience.
Application:
roofing, pond liners and applications that need resistance to strong mineral acids.

35. POLYACRYLIC RUBBERS, ACM
Better resistance but poorer low temperature resistance compared with polybutylacrylate.
High temperature resistance up to 200°C & good resistance to oil, ozone, sunlight and weathering
Resistance to swelling and deterioration by hot hydrocarbon oils, extreme pressure lubricants, and transmission and hydraulic fluids

36. Heat are superior to those of NBR.
Resistance to water and chemicals containing hydroxyl groups
Application
automation engine and transmission seals
gasket and 0-rings.

37. FLUOROCARBON RUBBERS (FKM)
The best known rubbers are those by the name Viton.
excellent resistance to oils, fuels, lubricants and most mineral acids and also resist many aliphatic and aromatic hydrocarbons like carbon tetrachloride and xylene. These rubbers are flame resistant and do not support combustion.

38. poor resistance towards some polar solvents like low molecular weight esters and ethers, ketones, certain amines, hot anhydrous hydrofluoric acid and certain proprietary hydraulic fluids)
Applications of FKM include automotive
fuel hose lines
seals
flue duct expansion joints

39. SILICONE RUBBERS
Inert chemically, with no taste or smell, unaffected by atmospheric expose and do not show ozone cracking with excellent electrical insulation and high permeability to gases.
Mechanical properties TS are low but change very little when measured at higher temperature (150°C). Its abrasion and tear strength are also poor

40. Oil resistance is about the same as that of chloroprene rubbers but poor resistance to acid and alkali, oil, gasoline and solvent.
The cost of the raw rubber is higher than most rubbers
Application:
in aerospace, medical, food contact, and automotive ignition cable.

41. POLYURETHANE RUBBERS
Resistance to ozone, oil, and oxidation and good aging properties.
It also has good TS, tear strength, excellent abrasion and high toughness.
However, they do suffer from limited resistance to hydrolysis.

42. Application
door frames,
window headers,
medallions
rosettes.

43. POLYSULPHIDE RUBBERS Polysulphide rubbers also know as "Thiokol“
low permeability and good resistance to weathering.
poor physical properties, often with unpleasant odor but outstanding oil, solvent and chemical resistance.

44. Application
fuel hose and tubing and as binder and for printing rollers
Liquid polymers are useful as caulking compounds and sealants and as castable rubbers, e.g. encapsulation.

45. THANK YOU