SlideShare a Scribd company logo
1 of 16
Download to read offline
B.E. SEMESTER-I
ENGINEERING CHEMISTRY
UNIT (POLYMER)
Dr. R. M. KHARATE
DEPATMENT OF
APPLED SCIENCES AND HUMANITIES
CLASSIFICATION OF POLYMERS
POLYMERS
METHOD OF
PREPARATION
PHYSICAL
PROPERTIES
STRUCTURE
1. ADDITION
POLYMERIZATION
2. CONDENSATION
POLYMERIZATION
1.ELASTOMERS
2. THERMOPLASTICS
3. THERMOSETTING
1. LINEAR CHAIN POLYMER
2. HOMO POLYMER
3. CO-POLYMER
4. BRANCHED POLYMER
5. BLOCK POLYMER
6. GRAFT POLYMER
CLASSIFICATION OF POLYMERS ON THE BASIS OF STRUCTURE
INDIVIDUAL POLYMERS
POLYVINYL CHLORIDE (PVC)
CRACKING
V.P. 500
0
C
150
0
CAlCl3
52
0
C, 9 atm.
Peroxide
INDIVIDUAL POLYMERS
POLYVINYL CHLORIDE (PVC)
Properties :
1. It is colourless, odourless, tasteless, noninflatable powder.
2. It shows chemical resistance towards atmospheric oxygen, acids,
alkalies But it is soluble in hot chlorinated hydrocarbon like
ethylchloride
Unplastizied PVC is rigid in naure and therefore it Is used in acid
recovery plant, for making pipes,Sheets, as tank linging , light
fitting, safety helmets,Refrigerator components, toys etc
Plasticized PVC is prepared by adding plastisizer such as
dibutyl-phthalate to rigid PVC . It gives flexibility and water proof
Nature to plasticized PVC. Therefore it use for making
1. Kitchen appliences
2. Curtaining’s
3. Ladies handbags
4. Raincoats, table-cloth, shoes for beach were
INDIVIDUAL POLYMERS
POLYTETRAFLUROETHYLENE (PTFE)
Properties: Strong polymer (C-F bond) , high softening
point (330
0
C), shows resistance towards acids , alkalis
but gets attacked by hot alkali metals, high electrical
insulation properties, excellent toughness and heat
resistance.
Applications: Wire and cable insulation , Laminates for
printed circuitry , non lubricating bearings, packing volves,
gaskets, insulator for motors , generators and transformer
PHENOL-FORMALDEHYDE RESIN (BAKELITE)
It is a condensation product of phenol and formaldehyde. It
is prepared by reacting phenol with formaldehyde in
presence of acid or alkali to give mono, di, tri methylol
phenols. The product formed depends upon the following
factors.
1. Phenol to Formaldehyde ratio (P/F ratio)
2. The kind of catalyst used (acid or alkali)
3. Tempt and time of reaction
PHENOL-FORMALDEHYDE RESIN (BAKELITE)
Case-I. P/F > 1 Catalyst used is acid.
The methylol derivatives condenses with phenol to form dihydroxy
diphenyl methane. These on further condensation gives the low
molecular weight linear Bakelite(Novalac)
Further condensation
Properties of Bakelite:
1. It is hard , rigid and strong material
2. Excellent heat and moisture resistance
3. Good electrical insulation characteristics.
4. Dark pinkish brown colored .
5. Water , acids, salts resistant but affected by alkalis.
Applications of Bakelite:
1. Electrical appliances in the form of switches, plugs,
heater handles etc.
2. Telephone parts, radio , TV Cabinets, bearings.
3. Binding material for plywood.
4. In paints and varnishes.
5. In production of ion exchange resin(as H
+
Exchanger ).
RUBBERS OR ELASTOMERS
VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER
Rubber is a polymer which when stretched elongest 4 to 10 times and as
soon as
stretching force is releases , it comes to its original position.
Types of rubber:
1 Natural rubber
2. Synthetic rubber
Natural rubber: It is a elastic polymer obtained naturally from the fluid
or emulsion of a rubber tree (Hevea Brasiliensis) . The natural rubber
contains number of isoprene units(monomers) so it is called as
polyisoprene .
2-methyl 1,3 butadiene
Isoprene Polyisoprene
RUBBERS OR ELASTOMERS
VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER
Preparation:
The latex is obtained from the bark of rubber tree. Then following two
processes are carried on the latex.
1. Creping:
Latex +
water
Filter 1% Acetic
acid
Coagulated
white mass
Passes
through
creping
machine
(Roller)
Sheet
(creped
rubber)
Sheet
Pass through vapours
of tar oil for 4 days(at
40-50 oC)
Increases storage life of
rubber
2. Smoking
Drawbacks of natural rubber:
Brittle at low temperature , low tensile strength absorbs water,
attacked by non-polar solvents And oxiding agents, on oxidation in air
shows change in color , little durability, when stretched To great
extent deforms permanently , low electrical insulation character, high
elasticity , poor Chemical resistance
RUBBERS OR ELASTOMERS
VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER
Vulcanization: To improve the properties of rubber Good Year in
1839 discovered a process known as vulcanization.
Rubber
5 % Sulphur Tough,
Frictionless
rubber
Accelerator
Thiourea
Increases
rate of
vulcanization
Activator
ZnO
Activate the
action of
accelerator
Antioxidants
Prevents
oxidation of
rubber
Fillers like carbon
black or silica
Coluring agents
Rubber
having
particular
color
110 – 140
0
C
TiO2
Lead
chromate
Chromium
oxide
Ferric
oxide
SYNTHETIC RUBBERS
STYRENE RUBBER (GR-S OR BUNA-S ORSBR OR BSR)
Preparation: It is prepared by
Addition Co-polymerization of two
monomers Butadiene(75%) and
styrene(25%) or in 3:1 ratio in
presence of Na as a catalyst
Properties:
1. Possesses high abrasion resistance
2. High load bearing capacity
3. Oxidizes readily
Applications:
1. Motor tyres, Gaskets
2. Shoe soles
3. Cable insulator
SYNTHETIC RUBBERS
NITRILE RUBBER (GR-A OR BUNA-N OR BUTADIENE-ACRILONITRILE RUBBER
Preparation:
It is prepared by Addition Co-polymerization of two monomers
Butadiene(75%) and Acrylonitrile (25%) or in 3:1 ratio in presence
of peroxide.
Properties:
1. Possesses good resistance towards heat, oils, acids but less
resistance towards alkalis.
2. It can be vulcanized 3. Good electrical insulation properties
Applications:
1. For making tank lingings
2. In manufacturing of aircraft components, printing rollers, automobile parts
3. As a oil repellent
1,3-Butadiene
SYNTHETIC RUBBERS
BUTYL RUBBER
BUTYL RUBBER
Preparation:
It is prepared by Addition Co-polymerization of two monomers
Isobutylene and Isoprene.
Properties:
1. Possesses good abrasion and heat resistance
2. Good resistance towards polar solvents but easily attacked by
hydrocarbons.
Applications:
1. For making cycle and automobile tubes, hoses, conveyer belts,
tank linings, insulation for high voltage wires etc.

More Related Content

Similar to Polymer (Kharate sir).pdf

Basic organic chemistry and polymers
Basic organic chemistry and polymersBasic organic chemistry and polymers
Basic organic chemistry and polymersSalman Faris
 
Chapter 9 manufacture substances
Chapter 9 manufacture substancesChapter 9 manufacture substances
Chapter 9 manufacture substancesFaridah Hamat
 
Zinc ferrite nano pigment and its use in anti-corrosive coatings
Zinc ferrite nano pigment and its use in anti-corrosive coatingsZinc ferrite nano pigment and its use in anti-corrosive coatings
Zinc ferrite nano pigment and its use in anti-corrosive coatingsMayur Khandait
 
Thermosetting plastics & rubber
Thermosetting plastics & rubberThermosetting plastics & rubber
Thermosetting plastics & rubberDevesh Tripathi
 
Treatment of tannery wastewater . susan
Treatment of tannery wastewater . susanTreatment of tannery wastewater . susan
Treatment of tannery wastewater . susananniesj
 
Poly olefins - Manufacturing & applications
Poly olefins - Manufacturing & applicationsPoly olefins - Manufacturing & applications
Poly olefins - Manufacturing & applicationsAAMIR NURLE
 
Polymers in everyday life.
Polymers in everyday life.Polymers in everyday life.
Polymers in everyday life.Pankaj Das
 

Similar to Polymer (Kharate sir).pdf (20)

Solids-and-Polymers.pptx
Solids-and-Polymers.pptxSolids-and-Polymers.pptx
Solids-and-Polymers.pptx
 
Acrylic fibre
Acrylic fibreAcrylic fibre
Acrylic fibre
 
Polymer and its types
Polymer and its typesPolymer and its types
Polymer and its types
 
Basic organic chemistry and polymers
Basic organic chemistry and polymersBasic organic chemistry and polymers
Basic organic chemistry and polymers
 
Chapter 9 manufacture substances
Chapter 9 manufacture substancesChapter 9 manufacture substances
Chapter 9 manufacture substances
 
Polysulfone
PolysulfonePolysulfone
Polysulfone
 
Zinc ferrite nano pigment and its use in anti-corrosive coatings
Zinc ferrite nano pigment and its use in anti-corrosive coatingsZinc ferrite nano pigment and its use in anti-corrosive coatings
Zinc ferrite nano pigment and its use in anti-corrosive coatings
 
Bj25364370
Bj25364370Bj25364370
Bj25364370
 
Polymer ppt
Polymer pptPolymer ppt
Polymer ppt
 
Thermosetting plastics & rubber
Thermosetting plastics & rubberThermosetting plastics & rubber
Thermosetting plastics & rubber
 
Treatment of tannery wastewater . susan
Treatment of tannery wastewater . susanTreatment of tannery wastewater . susan
Treatment of tannery wastewater . susan
 
special concrete
special concrete special concrete
special concrete
 
denture base Resins
denture base Resinsdenture base Resins
denture base Resins
 
Speciality Polymers
Speciality PolymersSpeciality Polymers
Speciality Polymers
 
Poly olefins - Manufacturing & applications
Poly olefins - Manufacturing & applicationsPoly olefins - Manufacturing & applications
Poly olefins - Manufacturing & applications
 
Plastic 1
Plastic 1Plastic 1
Plastic 1
 
Polymer Chemistry
Polymer ChemistryPolymer Chemistry
Polymer Chemistry
 
Polymers in everyday life.
Polymers in everyday life.Polymers in everyday life.
Polymers in everyday life.
 
Denture Base Materials
Denture Base MaterialsDenture Base Materials
Denture Base Materials
 
Introduction to material science
Introduction to material scienceIntroduction to material science
Introduction to material science
 

Recently uploaded

Theory of Machine Notes / Lecture Material .pdf
Theory of Machine Notes / Lecture Material .pdfTheory of Machine Notes / Lecture Material .pdf
Theory of Machine Notes / Lecture Material .pdfShreyas Pandit
 
Madani.store - Planning - Interview Questions
Madani.store - Planning - Interview QuestionsMadani.store - Planning - Interview Questions
Madani.store - Planning - Interview QuestionsKarim Gaber
 
Structural Integrity Assessment Standards in Nigeria by Engr Nimot Muili
Structural Integrity Assessment Standards in Nigeria by Engr Nimot MuiliStructural Integrity Assessment Standards in Nigeria by Engr Nimot Muili
Structural Integrity Assessment Standards in Nigeria by Engr Nimot MuiliNimot Muili
 
ADM100 Running Book for sap basis domain study
ADM100 Running Book for sap basis domain studyADM100 Running Book for sap basis domain study
ADM100 Running Book for sap basis domain studydhruvamdhruvil123
 
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATION
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATIONWAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATION
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATIONgerogepatton
 
Defining the Clouds for entriprises.pptx
Defining the Clouds for entriprises.pptxDefining the Clouds for entriprises.pptx
Defining the Clouds for entriprises.pptxAshwiniTodkar4
 
Network Enhancements on BitVisor for BitVisor Summit 12
Network Enhancements on BitVisor for BitVisor Summit 12Network Enhancements on BitVisor for BitVisor Summit 12
Network Enhancements on BitVisor for BitVisor Summit 12cjchen22
 
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENT
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENTFUNCTIONAL AND NON FUNCTIONAL REQUIREMENT
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENTSneha Padhiar
 
priority interrupt computer organization
priority interrupt computer organizationpriority interrupt computer organization
priority interrupt computer organizationchnrketan
 
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...arifengg7
 
Prach: A Feature-Rich Platform Empowering the Autism Community
Prach: A Feature-Rich Platform Empowering the Autism CommunityPrach: A Feature-Rich Platform Empowering the Autism Community
Prach: A Feature-Rich Platform Empowering the Autism Communityprachaibot
 
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...shreenathji26
 
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...Ayisha586983
 
Overview of IS 16700:2023 (by priyansh verma)
Overview of IS 16700:2023 (by priyansh verma)Overview of IS 16700:2023 (by priyansh verma)
Overview of IS 16700:2023 (by priyansh verma)Priyansh
 
Detection&Tracking - Thermal imaging object detection and tracking
Detection&Tracking - Thermal imaging object detection and trackingDetection&Tracking - Thermal imaging object detection and tracking
Detection&Tracking - Thermal imaging object detection and trackinghadarpinhas1
 
AntColonyOptimizationManetNetworkAODV.pptx
AntColonyOptimizationManetNetworkAODV.pptxAntColonyOptimizationManetNetworkAODV.pptx
AntColonyOptimizationManetNetworkAODV.pptxLina Kadam
 
Curve setting (Basic Mine Surveying)_MI10412MI.pptx
Curve setting (Basic Mine Surveying)_MI10412MI.pptxCurve setting (Basic Mine Surveying)_MI10412MI.pptx
Curve setting (Basic Mine Surveying)_MI10412MI.pptxRomil Mishra
 
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...gerogepatton
 
Road Development plans of India-Transportation Engineering
Road Development plans of India-Transportation EngineeringRoad Development plans of India-Transportation Engineering
Road Development plans of India-Transportation EngineeringSayli Madhale
 

Recently uploaded (20)

Theory of Machine Notes / Lecture Material .pdf
Theory of Machine Notes / Lecture Material .pdfTheory of Machine Notes / Lecture Material .pdf
Theory of Machine Notes / Lecture Material .pdf
 
Madani.store - Planning - Interview Questions
Madani.store - Planning - Interview QuestionsMadani.store - Planning - Interview Questions
Madani.store - Planning - Interview Questions
 
Structural Integrity Assessment Standards in Nigeria by Engr Nimot Muili
Structural Integrity Assessment Standards in Nigeria by Engr Nimot MuiliStructural Integrity Assessment Standards in Nigeria by Engr Nimot Muili
Structural Integrity Assessment Standards in Nigeria by Engr Nimot Muili
 
ADM100 Running Book for sap basis domain study
ADM100 Running Book for sap basis domain studyADM100 Running Book for sap basis domain study
ADM100 Running Book for sap basis domain study
 
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATION
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATIONWAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATION
WAVELET SCATTERING TRANSFORM FOR ECG CARDIOVASCULAR DISEASE CLASSIFICATION
 
Defining the Clouds for entriprises.pptx
Defining the Clouds for entriprises.pptxDefining the Clouds for entriprises.pptx
Defining the Clouds for entriprises.pptx
 
Network Enhancements on BitVisor for BitVisor Summit 12
Network Enhancements on BitVisor for BitVisor Summit 12Network Enhancements on BitVisor for BitVisor Summit 12
Network Enhancements on BitVisor for BitVisor Summit 12
 
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENT
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENTFUNCTIONAL AND NON FUNCTIONAL REQUIREMENT
FUNCTIONAL AND NON FUNCTIONAL REQUIREMENT
 
priority interrupt computer organization
priority interrupt computer organizationpriority interrupt computer organization
priority interrupt computer organization
 
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...
Analysis and Evaluation of Dal Lake Biomass for Conversion to Fuel/Green fert...
 
Prach: A Feature-Rich Platform Empowering the Autism Community
Prach: A Feature-Rich Platform Empowering the Autism CommunityPrach: A Feature-Rich Platform Empowering the Autism Community
Prach: A Feature-Rich Platform Empowering the Autism Community
 
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...
Introduction to Artificial Intelligence: Intelligent Agents, State Space Sear...
 
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...
Submerged Combustion, Explosion Flame Combustion, Pulsating Combustion, and E...
 
Overview of IS 16700:2023 (by priyansh verma)
Overview of IS 16700:2023 (by priyansh verma)Overview of IS 16700:2023 (by priyansh verma)
Overview of IS 16700:2023 (by priyansh verma)
 
ASME-B31.4-2019-estandar para diseño de ductos
ASME-B31.4-2019-estandar para diseño de ductosASME-B31.4-2019-estandar para diseño de ductos
ASME-B31.4-2019-estandar para diseño de ductos
 
Detection&Tracking - Thermal imaging object detection and tracking
Detection&Tracking - Thermal imaging object detection and trackingDetection&Tracking - Thermal imaging object detection and tracking
Detection&Tracking - Thermal imaging object detection and tracking
 
AntColonyOptimizationManetNetworkAODV.pptx
AntColonyOptimizationManetNetworkAODV.pptxAntColonyOptimizationManetNetworkAODV.pptx
AntColonyOptimizationManetNetworkAODV.pptx
 
Curve setting (Basic Mine Surveying)_MI10412MI.pptx
Curve setting (Basic Mine Surveying)_MI10412MI.pptxCurve setting (Basic Mine Surveying)_MI10412MI.pptx
Curve setting (Basic Mine Surveying)_MI10412MI.pptx
 
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...
March 2024 - Top 10 Read Articles in Artificial Intelligence and Applications...
 
Road Development plans of India-Transportation Engineering
Road Development plans of India-Transportation EngineeringRoad Development plans of India-Transportation Engineering
Road Development plans of India-Transportation Engineering
 

Polymer (Kharate sir).pdf

  • 1. B.E. SEMESTER-I ENGINEERING CHEMISTRY UNIT (POLYMER) Dr. R. M. KHARATE DEPATMENT OF APPLED SCIENCES AND HUMANITIES
  • 2. CLASSIFICATION OF POLYMERS POLYMERS METHOD OF PREPARATION PHYSICAL PROPERTIES STRUCTURE 1. ADDITION POLYMERIZATION 2. CONDENSATION POLYMERIZATION 1.ELASTOMERS 2. THERMOPLASTICS 3. THERMOSETTING 1. LINEAR CHAIN POLYMER 2. HOMO POLYMER 3. CO-POLYMER 4. BRANCHED POLYMER 5. BLOCK POLYMER 6. GRAFT POLYMER
  • 3. CLASSIFICATION OF POLYMERS ON THE BASIS OF STRUCTURE
  • 4. INDIVIDUAL POLYMERS POLYVINYL CHLORIDE (PVC) CRACKING V.P. 500 0 C 150 0 CAlCl3 52 0 C, 9 atm. Peroxide
  • 5. INDIVIDUAL POLYMERS POLYVINYL CHLORIDE (PVC) Properties : 1. It is colourless, odourless, tasteless, noninflatable powder. 2. It shows chemical resistance towards atmospheric oxygen, acids, alkalies But it is soluble in hot chlorinated hydrocarbon like ethylchloride Unplastizied PVC is rigid in naure and therefore it Is used in acid recovery plant, for making pipes,Sheets, as tank linging , light fitting, safety helmets,Refrigerator components, toys etc Plasticized PVC is prepared by adding plastisizer such as dibutyl-phthalate to rigid PVC . It gives flexibility and water proof Nature to plasticized PVC. Therefore it use for making 1. Kitchen appliences 2. Curtaining’s 3. Ladies handbags 4. Raincoats, table-cloth, shoes for beach were
  • 6. INDIVIDUAL POLYMERS POLYTETRAFLUROETHYLENE (PTFE) Properties: Strong polymer (C-F bond) , high softening point (330 0 C), shows resistance towards acids , alkalis but gets attacked by hot alkali metals, high electrical insulation properties, excellent toughness and heat resistance. Applications: Wire and cable insulation , Laminates for printed circuitry , non lubricating bearings, packing volves, gaskets, insulator for motors , generators and transformer
  • 7. PHENOL-FORMALDEHYDE RESIN (BAKELITE) It is a condensation product of phenol and formaldehyde. It is prepared by reacting phenol with formaldehyde in presence of acid or alkali to give mono, di, tri methylol phenols. The product formed depends upon the following factors. 1. Phenol to Formaldehyde ratio (P/F ratio) 2. The kind of catalyst used (acid or alkali) 3. Tempt and time of reaction
  • 8. PHENOL-FORMALDEHYDE RESIN (BAKELITE) Case-I. P/F > 1 Catalyst used is acid. The methylol derivatives condenses with phenol to form dihydroxy diphenyl methane. These on further condensation gives the low molecular weight linear Bakelite(Novalac) Further condensation
  • 9.
  • 10. Properties of Bakelite: 1. It is hard , rigid and strong material 2. Excellent heat and moisture resistance 3. Good electrical insulation characteristics. 4. Dark pinkish brown colored . 5. Water , acids, salts resistant but affected by alkalis. Applications of Bakelite: 1. Electrical appliances in the form of switches, plugs, heater handles etc. 2. Telephone parts, radio , TV Cabinets, bearings. 3. Binding material for plywood. 4. In paints and varnishes. 5. In production of ion exchange resin(as H + Exchanger ).
  • 11. RUBBERS OR ELASTOMERS VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER Rubber is a polymer which when stretched elongest 4 to 10 times and as soon as stretching force is releases , it comes to its original position. Types of rubber: 1 Natural rubber 2. Synthetic rubber Natural rubber: It is a elastic polymer obtained naturally from the fluid or emulsion of a rubber tree (Hevea Brasiliensis) . The natural rubber contains number of isoprene units(monomers) so it is called as polyisoprene . 2-methyl 1,3 butadiene Isoprene Polyisoprene
  • 12. RUBBERS OR ELASTOMERS VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER Preparation: The latex is obtained from the bark of rubber tree. Then following two processes are carried on the latex. 1. Creping: Latex + water Filter 1% Acetic acid Coagulated white mass Passes through creping machine (Roller) Sheet (creped rubber) Sheet Pass through vapours of tar oil for 4 days(at 40-50 oC) Increases storage life of rubber 2. Smoking Drawbacks of natural rubber: Brittle at low temperature , low tensile strength absorbs water, attacked by non-polar solvents And oxiding agents, on oxidation in air shows change in color , little durability, when stretched To great extent deforms permanently , low electrical insulation character, high elasticity , poor Chemical resistance
  • 13. RUBBERS OR ELASTOMERS VALCANIZATION OR RECOMPOUNDING OR CURING OF RUBBER Vulcanization: To improve the properties of rubber Good Year in 1839 discovered a process known as vulcanization. Rubber 5 % Sulphur Tough, Frictionless rubber Accelerator Thiourea Increases rate of vulcanization Activator ZnO Activate the action of accelerator Antioxidants Prevents oxidation of rubber Fillers like carbon black or silica Coluring agents Rubber having particular color 110 – 140 0 C TiO2 Lead chromate Chromium oxide Ferric oxide
  • 14. SYNTHETIC RUBBERS STYRENE RUBBER (GR-S OR BUNA-S ORSBR OR BSR) Preparation: It is prepared by Addition Co-polymerization of two monomers Butadiene(75%) and styrene(25%) or in 3:1 ratio in presence of Na as a catalyst Properties: 1. Possesses high abrasion resistance 2. High load bearing capacity 3. Oxidizes readily Applications: 1. Motor tyres, Gaskets 2. Shoe soles 3. Cable insulator
  • 15. SYNTHETIC RUBBERS NITRILE RUBBER (GR-A OR BUNA-N OR BUTADIENE-ACRILONITRILE RUBBER Preparation: It is prepared by Addition Co-polymerization of two monomers Butadiene(75%) and Acrylonitrile (25%) or in 3:1 ratio in presence of peroxide. Properties: 1. Possesses good resistance towards heat, oils, acids but less resistance towards alkalis. 2. It can be vulcanized 3. Good electrical insulation properties Applications: 1. For making tank lingings 2. In manufacturing of aircraft components, printing rollers, automobile parts 3. As a oil repellent 1,3-Butadiene
  • 16. SYNTHETIC RUBBERS BUTYL RUBBER BUTYL RUBBER Preparation: It is prepared by Addition Co-polymerization of two monomers Isobutylene and Isoprene. Properties: 1. Possesses good abrasion and heat resistance 2. Good resistance towards polar solvents but easily attacked by hydrocarbons. Applications: 1. For making cycle and automobile tubes, hoses, conveyer belts, tank linings, insulation for high voltage wires etc.