Low Dense Polyethylene High Dense Polyethylene POLYETHYLENE SBR PROPERTIES OF POLYMERS CLASSIFICATION of polymers

1. POLYMERS

2. OBJECTIVES
 INTRODUCTION ABOUT POLYMERS
• HISTORY & CLASSIFIACTION
 LDPE
 LLDPE
 HDPE
 POLYETHYLENE
 SBR

3. INTRODUCTION ABOUT POLYMERS
• POLYMER (GREEK, POLY-MANY, MERS-UNIT OR PART)
• POLYMER HAVE INFLUENCED OUR LIFE STYLE IN SUCH AWAY THAT IT WOULD NOT
BE WRONG TO SAY THAT WE ARE IN POLYMER AGE. FOR EXAMPLE, HOUSE-HOLD
UTENSILS, CLOTHES, FURNITURE, AUTOMOBILE, SPACE AIRCRAFT ETC.
• THESE ARE SO FREQUENTLY USE BY PEOPLE THAT A COMMON MAN CALLS THEM BY
NAMES LIKE PLASTICS, FIBRES, RUBBERS RESINS ETC.
• POLYMERS ARE LARGE BUNCH OF MONOMER UNITS, NORMALLY IN THE RANGE OF
FEW THOUSAND TO 1,00000 UNITS.
• THE PROPERTIES OF POLYMERS ARE VERY DIFFERENT WITH THAT OF MONOMERS.
• POLYMERS ARE OF MANY TYPES, BUT OUR AREA OF INTEREST IS IN THE RUBBER
TYPE OR PLASTIC TYPE POLYMERS.

4. • POLYTHENE IS A POLYMER FORMED BY THE LINKING TOGETHER OF LARGE NO OF
OF ETHANE (C2H4 ) MOLECULES.
• POLYMERS ARE MACRO MOLECULES BUILT UP BY THE LINKAGE OF SMALL
MOLECULES (MONOMERS) BY CHEMICAL BOND INTO A LONG CHAIN.
• POLYMER MEANS A SUBSTANCE WITH MANY PARTS. “POLYMER IS A UNION OF
MONOMERS.” “ POLYMERS ARE COMPOUNDS FORMED BY A MORE OR LESS
REGULAR REPETATION OF LARGE NUMBER OF THE SAME AND DIFFERET ATOMIC
GROUPINGS THAT ARE JOINED BY A CHEMICAL BONDS INTO A LONG CHAIN. ”
• MATERIALS USED AS PLASTICS, RUBBERS, FIBRES, ADHESIVES AND SURFACE
COATING MATERIALS ARE ALL POLYMERS.

5. PROPERTIES OF POLYMERS.
• LIGHT IN WEIGHT.
• HIGHER STRENGTH TO WEIGHT RATIO.
• WIDER & DESIGN FREEDOM.
• EASY PROCESSABILITY.
• LOW ENERGY REQUIRED FOR MANUFACTURE.
• MINIMUM POSTS FINISHING.
• CORROSION RESISTANT.
• LOW CREEP.
• BETTER AESTHETIC LOOK.

6. • WIDE COLOUR RANGE.
• EASY REPLACEABLE.
• RESISTANT TO CHEMICALS.
• RESISTANT TO WATER.
• LOW MAIRENANCE COST.
• ADHESIVE OF PLASTIC RESIN ARE VERY STRONG, DURABLE & PRODUCE VERY THI
FILM.

7. CLASSIFICATION OF POLYMERS
1. ORIGIN.
• NATURAL.( RUBBER, SILK,STARCH,PROTEINS ETC.)
• SEMISYTHETIC (CHEMICALLY MODIFIED N.POLYMERS)
• SYNTHETIC. ( MAN MADE POLYMERS )
2. MODE OF FORMATION.
• ADDITION.(PE,PP,PS ETC)
• CONDENSATION.(NYLON,POLYESTER ETC)
3. BASED ON STRUCTURE/SHAPE.
• LINEAR. (HDPE PVC,PS ETC.)
• BRANCHED.(LDPE)
• CROSSLINKED.(BAKELITE)

8. 4. THERMAL RESPONSE.
• THERMOPLASTICS
• THERMOSETTING
5. MECHNICAL PROPERTIES & BEHAVIOUR.
• RUBBER.
• PLASTICS.
• FIBRES
6. TYPES OF MESOMERS INVOLVED I THE POLYMERS.
• HOMOPOLYMERS.
• HETRO POLYMERS

9. Natural Gas Liquids (Ethane, Propane)
or Naphtha (from Crude Oil)
Steam Cracking
Ethylene, Propylene
Other Polymers Chemicals
POLYETHYLENE

10. LOW-DENSITY POLYETHYLENE (LDPE)
• LOW-DENSITY POLYETHYLENE (LDPE) IS A THERMOPLASTIC MADE FROM THE
MONOMER ETHYLENE
• IMPERIAL CHEMICAL INDUSTRIES FIRST DISCOVERED LOW-DENSITY POLYETHYLENE
IN 1933. ITS FIRST
• COMMERCIAL USE CAME DURING WORLD WAR II, WHEN
• IT WAS USED AS INSULATION ON RADAR CABLES.
• LOW DENSITY POLYETHYLENE) IS DEFINED BY A ENSITY RANGE OF 0.910 - 0.940
G/CM3
• IT HAS A HIGH DEGREE OF SHORT AND LONG CHAIN BRANCHING , WHICH MEANS
THAT THE CHAINS DO NOT PACK INTO THE CRYSTAL STRUCTURE AS WELL.
• THIS RESULTS IN A LOWER TENSILE STRENGTH AND INCREASED DUCTILITY.
• CREATED BY FREE RADICAL POLYMERIZATION

11. • PROCESS THEORY 1
FREE RADICAL REACTION
I → R·+ R·
INITIATION
INITIATORS: TYPICALLY ORGANIC PEROXIDES „
PROPAGATION
R· + CH2CH2 →RCH2CH2·
R(CH2CH2) n-1CH2CH 2· + CH2CH 2 →
R(CH2CH2)NCH2CH2·
TERMINATION
RX·+RY·→ PX+Y
DISPROPORTIONING
RX·+RY·→ PX + PY

13. LINEAR LOW-DENSITY POLYETHYLENE (LLDPE)
• LLDPE IS DEFINED BY A DENSITY RANGE OF 0.915–0.925 G/CM3. LLDPE IS A SUBSTANTIALLY
LINEAR POLYMER WITH SIGNIFICANT NUMBERS OF SHORT BRANCHES, COMMONLY MADE BY
COPOLYMERIZATION OF ETHYLENE WITH SHORT-CHAIN ALPHA-OLEFINS (FOR EXAMPLE, 1-
BUTENE, 1-HEXENE AND 1-OCTENE).
• PRODUCTION METHODS
• LLDPE IS PRODUCED USING A LOW PRESSURE IN EITHER GAS PHASE REACTOR OR SOLUTION
PROCESS.
• THE PRODUCTION OF LLDPE IS INITIATED BY TRANSITION METAL CATALYST PARTICULARLY
ZIEGLER OR PHILIPS TYPE CATALYST.
• USUALLY OCTENE IS THE CO-POLYMER IN SOLUTION PHASE WHILE BUTENE AND OCTENE ARE
COPOLYMERIZED WITH ETHYLENE IN GAS PHASE REACTOR.
• THE LLDPE RESIN PRODUCED IN GAS PHASE REACTOR IS IN GRANULAR FORM AND MAY BE
SOLD AS GRANULES OR PROCESSED INTO PELLETS.
• THE RAW LLDPE IS MIXED WITH ADDITIVES TO PRODUCE VARIOUS GRADES WHICH CAN BE

14. HIGH-DENSITY POLYETHYLENE (HDPE)
• IN 1953, KARL ZIEGLER AND ERHARD HOLZKAMP INVENTED HIGH-DENSITY
POLYETHYLENE (HDPE). THE PROCESS INCLUDED THE USE OF CATALYSTS AND LOW
PRESSURE, WHICH IS THE BASIS FOR THE FORMULATION OF MANY VARIETIES OF
POLYETHYLENE COMPOUNDS.
• TWO YEARS LATER, IN 1955, HDPE WAS PRODUCED AS PIPE. FOR HIS SUCCESSFUL
INVENTION OF HDPE, ZIEGLER WAS AWARDED THE 1963 NOBEL PRIZE FOR
CHEMISTRY.
• HIGH-DENSITY POLYETHYLENE (HDPE) IS THERMOPLASTIC POLYMER. IT EXHIBIT
ATTRIBUTES OF TOUGHNESS, FLEXIBILITY, CHEMICAL RESISTANCE AND NON-
CONDUCTING ELECTRICAL PROPERTIES. IT IS USED IN HIGHWAY DRAINAGE PIPES
SINCE THE EARLY 1970S. SINCE THEN, GROWING OUT OF APPLICATIONS FOR
AGRICULTURAL DRAINAGE, TOYS, UTENSILS, FILMS, BOTTLES AND PROCESSING
EQUIPMENT. WIRE AND CABLE INSULATIONS.

16. POLYPROPYLENE

17. • THE ETHYLENE IS FIRST PUMPED INTO A REACTOR WHERE IT IS MIXED WITH
CATALYST DILUENTS STREAM.
• THE OPTIMUM TEMPERATURE AND PRESSURE MAINTAINED SHOULD BE 70OC
AND 7 ATMS GAGE.
• THE EFFLUENT STREAM THEN FOLLOWS ACROSS A SERIES OF FLASH DRUMS
INORDER TO REMOVE THE SOLVENT FROM THE CATALYST. THE RESIDUAL
CATALYST AT THIS POINT IS REMOVED BY ADDING WATER.
• THE FLASHED SOLVENT IS THEREAFTER RECYCLED TO THE CATALYST MAKE –UP
UNIT AFTER APPROPRIATE DRYING AND REDISTILLATION. THE SLURRY WHICH
RESULTS IS THEN CENTRIFUGED TO REMOVE THE WATER, AND THE WATER IS
TREATED TO REMOVE THE CATALYST BEFORE RECYCLE. THE FINAL PRODUCTS
OF POLYETHYLENE SOLIDS ARE THEN DRIED, EXTRUDED AND GIVEN THE
REQUIRED FINAL FORMS.

18. STYRNE BUTADIENE RUBBER (SBR)
• THE PRODUCTION OF STYRENE BUTADIENE RUBBER (SBR) FOLLOWS ADDITION
POLYMERIZATION. ITS GLASS TRANSITION TEMPERATURE IS APPROXIMATELY -55OC,
BUT MAY VARY WITH THE STYRENE CONTENT.
• IT CAN BE USED EXTENSIVELY WITHIN THE TEMPERATURE RANGE OF -40 TO 100 OC.
IT MAY BE BLENDED WITH NATURAL RUBBER OR CAN BE USED BY ITSELF. IT HAS
GOOD ABRASION RESISTANCE PROPERTIES AND THE ADDITION OF ADDITIVES MAY
ENDOW IT WITH AGING STABILITY.
• SBR IS PRODUCED BY THE COPOLYMERIZATION OF BUTADIENE AND STYRENE BY
EMULSION POLYMERIZATION IN 3 : 1 WEIGHT RATIO.
• THE FRESH AND RECYCLE MONOMERS ARE PURIFIED BY 20 % AQUEOUS CAUSTIC
PURIFICATION. THEN THE STREAM IS CONTINUOUSLY PASSED THROUGH 6 TO 12
GLASS – LINED OR STAINLESS STEEL REACTORS. THE RESIDENCE TIME IN THESE
REACTORS RANGES FROM 5 TO 15 HOURS. STEAM HEATING, WATER COOLING AND
REFRIGERATION ARE CARRIED OUT IN THESE REACTORS. THESE REACTORS ARE
EQUIPPED FOR PRODUCING BOTH COLD AND HOT SBR. COLD SBR IS PRODUCED AT
5OC AND 1 ATM GAGE BY REFRIGERATION TECHNIQUES ; WHEREAS HOT SBR IS

19. Manufacture of Styrene Butadiene Rubber