PLASTICS AND PROCESSING AND ADDITIVES AND PETROCHEMICALS AND CHEMICALS AND POLLYMER

1. 1
Polymer Additives & Its Importance
By
Kirankumar Koli
CIPET: CSTS - AURANGABAD

2. WELCOME

3. ADDITIVES
• Polymers unsuitable for processing in pure
unmodified form
e.g. Polyolefin's – Oxidative degradation
due to heat and pressure during
processing.
PVC - Degradation at processing
temperature.

4. ADDITIVES
Any Substance that is added
generally in small concentration to
resins in order to :
• Alter their properties
• Facilitate processing
• Change the physical, chemical or
electrical properties of end products.
• Reduce the cost

5. Technological Requirements
5
o Stability against Long term thermal stability, Light
Stability(Outdoor/UV Exposure)
o Process Stability (FG Production)
o Stability against Metal caused degradation
o Resistance against Burning/degradation
o Prevention of Microbial Growth
o Change the properties of plastic materials
o Enlarge the field of application drastically
o Protect your plastic against alteration and degradation
o Help to meet the recycling requirements
o Extend the lifetime of products
o Differentiate properties with others

6. Requirements for Selection
• Effectiveness in their function
• Stable under processing conditions
• Stable under service conditions
• Economic
• Compatibility with Polymer Matrix
– At molecular level
• Neither Volatile nor extrude to the surface
• Neither bleed nor bloom
• Must have low vapour pressure at high
temperature
• Non Hazardous, non impart taste & odour

7. Classifications of Additives
Plastic Additives
Additives to modify plastics Additives achieve their effect
Properties by physical means by chemical reactions
Plasticizer Heat stabilizers
Lubricants Antioxidants
Impact modifiers UV absorbers
Fillers Flammable Retardants
Pigments, etc.

8. CLASSIFICATION
Assist Processing • Processing Stabilizer
• Lubricants - External
• Lubricants - Internal
Modify Bulk Mechanical
Properties
• Plasticizer
• Reinforcing filler
• Toughening Agents
Reduce Cost • Fillers
• Diluents & extenders

9. CLASSIFICATION
Surface Properties
Modifier
• Antistatic
• Anti Slip
• Anti wear
• Anti block
• Adhesion Promoters
Optical Properties
Modifier
• Nucleating Agents
• Colorants
Anti-Ageing • UV Absorbers
• Fungicides
Others • Blowing Agents
• Flame Retarders

10. Processing Stabilizers
• Prevent degradation which is caused by
– Heat
– Oxygen
• What Happens ?
– Oxygen combines with Polymer under high
temp to form carbonyl compounds which
leads to yellow & brown discolouration.

11. Processing Stabilizers
• Primary Stabilizers – Antioxidants
• Secondary Stabilizers – Peroxide
decomposes
• Chelating Agents – Metal deactivators
• Special Stabilizers (Heat Stabilizers) – for
halogenated polymers

12. Antioxidants-:
• Polymers when subjected to oxygen attack & if
1)there exists high concentration of unsaturated c-c bonds
2)residual polymerization catalyst
3)it is subjected to highly oxidizing conditions, then it undergo
oxidation.
-to overcome this problems  long service life, antioxidants are used.
Classification -:
1)primary: hindered phenolics acryl amines
2)secondary: phosphorous & sulphur containing compounds

13. Antioxidants
( Primary Stabilizer )
• They inhibit or retard the oxidative degradation
of materials at normal or elevated temperature
during processing, storage or service due to
– Heat
– Light
– Chemical Induction
• How it works?
– It interrupt the chain reaction by combining with
the free radicals forming a non reactive products
(Amount : 0.1 – 0.5%)

14. Effect of Oxidation
– Loss in Tensile Properties
– Discolouration i.e. yellowing,
– Increase in Brittleness
– Melt Flow Instability
– Change in appearance.
– Hardness increases.
– Loss of Gloss.
– loss of transparency.
– Cracking.
• Hindered Phenols or Aromatic Amines

15. Secondary Stabilizer – Peroxide
decomposes
• How it works?
– Peroxides are reduced to alcohols & are
deactivated.
• EX:
– Sulphur & Phosphorus Compounds such as
Sulphides, thioethers, tertiary phosphites &
phosphorates.

16. Chelating Agents – Metal
Deactivators
• Prevent degradation by metal ions
(impurities in polymers – ziegler-natta
redox initiators, fillers, pigments etc.)
• EX:
– Organic Phosphines & Phosphites
– Higher Nitrogenated compounds – Melamine,
diamine etc

17. Heat Stabilizers
• Prevent Degradation
• Absorb & Neutralize HCl gas evolved
• Prevent Oxidation reactions
• Prevent Discolouration
• Displace active substituents with stable
substituents

18. Heat Stabilizers
• Lead
– Tri Basic Lead Sulphate (TBLS)
– Dibasic Lead Sulphate (DBLS)
– Basic Lead Carbonate
– Dibasic Lead Phosphite
• Organo-tin
– Dibutyltin meleates
– Dibutyltin bis mercaptides
• Cadmium / Barium /Zinc
– Cadmium/Barium laurates
– Cadmium/Barium/Zinc Complexes

19. Synergistic Stabilizer Systems
• The term Synergism is used to describe
the combined effect of two or more
stabilizers, which is greater than the sum
of the effects of the individual stabilizers
used in isolation.
Effect (A+B) > Effect A + Effect B

20. Polymers are made of long chain molecules of varying sizes and
distributions. These polymers tend to be:
§ Relatively viscous above their melt temperature
§ “Sticky” above their melt temperature
Lubricants serve to decrease the frictional forces found between:
§ Polymer : Polymer
§ Polymer : Metal
§ Polymer : Filler
§ Filler : Filler
§ Filler : Metal
Lubricants

21. Lubricants or Flow Promoters
Functions :-
• To reduce friction between the material and the
processing equipment. ( Adhesive forces)
• To reduce heat & wear between two surfaces
either between the polymer molecules
( Cohesive forces) or between the polymeric
material and the equipment.
• Reduces thermal degradation of the polymer.
• Modifies flow characteristics.
• Homogenous the polymer melt with other polymer
additives.
• To prevent the plastic from sticking to the mould
surface during processing

22. Classification of Lubricants
Internal Lubricants
 Act in the interior of
melts
External Lubricants
 Act on the exterior of
melts
* Often, a lubricant will act as both an internal and external lubricant.

23. Benefits of Lubricants
Internal
 Promote flow
 Promote weld line
strength
 Minimize sink marks
 Improve die filling
 Reduce die swell
 Reduce head and back
pressure needed
 Lower heat deflection
temperature
External
 Provide metal release
 Help reduce process temp

24. Where are Lubricants Used?
Lubricants may be used in the processing of:
 Polyolefin's
 Polypropylenes
 Polyethylene's (both HDPE and LDPE)
 Polystyrenes
 Polyesters
 PET
 Polycarbonates
 ABS
 PVC is by far the largest application of lubricants
(80%)

25. Lubrication @ Extrusion Process

26. External Lubricants
• Prevent friction between polymer melt & metal
surface
• Prevent sticking to the metal parts
• They are usually high molecular compounds and
have non-polar groups.
• They have low compatibility with the polymer but
have high affinity for the metal surface.
• During processing they form a thin film between
polymer melt & metal surface.
• They improve surface finish & gloss.
• They help to reduce melt viscosity and give a high
output rate.

27. External Lubricants
• Metal Soaps
– Metal Stearates
– Zinc Stearates
– Calcium Stearates
– Magnesium Stearates
• Hydrocarbon waxes
• Stearic Acid & its calcium, lead, Ba, Cd Salt,
Hydro carbon & Esters

28. Internal Lubricants
• Promotes Flow by reducing cohesive forces
between molecular interfaces within the resin
• They are usually low molecular weight
compounds, having polar groups.
• They function by reducing intra-molecular friction
before and during the melt formation of the
polymer by promoting flow and reducing melt
viscosity of the polymeric mass.
• They also enhance polymer properties like heat
stability, impact strength, colour & clarity.

29. Internal Lubricants
• Amine Waxes
• Ester Derivatives
• Glyceryl mono stearate
• Long chain esters
• Fatty Acids & Amides
• Ethylene bi stear amide
• Zinc Stearates

30. Selection of Lubricants
• Metal Soaps – Low Compatibility with
polymer, so used as external lubricants
• Long Chain Fatty Acids – Used as Internal
Lubricants for polar polymers.
• Long Chain di-alkyl esters – Medium
compatibility, so act as external & internal
lubricants.
• High Molecular weight paraffin wax – low
compatibility with polar polymer, so used
as external lubricants.

31. GENERAL CHEMISTRIES OF LUBRICANTS
General Type Class of Compound Type Examples
Hydrocarbons Natural
hydrocarbons,
Synthetic
hydrocarbons
External Paraffin waxes,
Paraffin oils, Synthetic
paraffin's, LPE, PP etc.
Hydrocarbon
Derivatives
Fatty Acids, Fatty
Alcohols
External/Internal Stearic Acids, Cetyl,
Stearyl, Octadecyl etc.
Organic Acid
Derivatives
Metal salts (Soaps)
Amides
Esters & partial
esters
Ester waxes
Internal
External/Internal
External/Internal
Ca/Ba/Al/Pb/Zn
Stearates
Stearamide, Butyl
stearate, GMS,
Glycerol
Stearyl esters, Montan
acids esters etc.

32. Plasticizers or softeners
• Improve process ability by reducing Tg
• These are high boiling non-volatile
solvents
• Polar with a high Mol. Wt. ester type
organic compounds.
• Reduce internal friction between
polymer chain.

33. Effect of Plasticizers
• Easy melt
• Improve flexibility
• Increase Softness and Flexibility.
• Improve Process ability.
• Alters Softening point, Tensile Strength,
Elongation at break & Impact.

34. Types of Plasticizers
• Primary – These are highly compatible
with PVC and can be used alone.
• e.g.
– Phthalates – Di-Octyl Phthalate (DOP), Di Iso
Octyl Phthalate (DIOP)
– Phosphates – Tricresyl Phosphate (TCP),
– Sebacates,
– Adipates.

35. Types of Plasticizers
• Secondary – These are less compatible
with resin & and are usually employed
together with primary plasticizers.
• e.g.
– Di Octyl Sebacate (DOS)
– Adipic Acid Polyesters
– Epoxidised oil.

36. Extenders
• These are not used alone as plasticizers.
• They are limited compatibility with polymer.
• In conjunction with true plasticizers it enhance
the efficiency of plasticizers.
• Low Cost.
• It replaces the plasticizers without any adverse
effect on polymer.
e.g.
– Chlorinated paraffin wax,
– oil extracts.

37. Selection of Plasticizers
 Solvating power
 Efficiency
 Compatibility
 Flame retardant
 Toxicity
 Low Temp. Performance
 Cost

38. FILLERS
It is used to modify mechanical
properties & to reduce the cost.

39. Effect of Fillers
• The use of inert fillers can influence the
polymer properties in the following ways :-
– Increase in density.
– Increase in modulus of elasticity.
– Lower shrinkage.
– Increase in hardness.
– Increase in HDT.
– Reduction of raw material cost.
– For e.g. Calcium Carbonate,Red mud

40. Fillers
Purpose Filler
Bulk Wood Flour
Saw dust
Wood pulp
Sisal / jute
Purified cellulose
Mica / Rock

41. Fillers
Purpose Filler
Hardeners Inorganic Pigments
Mineral Powders
Metallic Oxides
Powder Metals
Graphite

42. Fillers
Purpose Filler
Chemical Resistance Glass Fibres & Fabrics
Synthetic Fibres & Fabrics
Graphite
Metallic Oxides
Thermal Insulation Asbestos
Ceramic Oxides
Silica

43. Fillers
Purpose Filler
Appearance Colour Pigments
Dyestuffs
Carbon Flakes
Powder Metals
Phosphorescent Minerals
Woven Fabrics

44. Fillers
Purpose Filler
Reinforcement Glass fibres
Asbestos Fibbers
Cellulose Fibbers
Cotton Fibbers
Papers
Synthetic Fibbers

45. Coupling Agents
These are used to increase the adhesion
between polymer & filler, fiber by covalent
bonds.
Ex: Methacrylato-chromo chloride used for
glass fibres & Polyester resin
Organosilanes are used for PVC , ABS and
PA

46. Antistatic Agents
• Static charge may built up simply by friction
with the ambient air
• Most plastics have low surface conductivity
• Static charge is not discharged fast enough
Troublesome effects like:
• Heavy contamination of plastics parts
• Shock as charge flows ( floor covering ,
door handles)

47. Antistatic Agents
• Chemicals added to plastics to reduce built
up of electrostatic charges on the surface of
materials
Accumulations can occur during processing
and at various handling points
• Static charges are dissipated by increasing
the surface conductivity

48. Antistatic Agents
• Prevent electrostatic charges – mostly seen in
PE, PP, PS, Nylons, Polyesters, Urathenes,
Cellulosics, Acrylics & Acrylonitriles
• Because of insulation properties electrical
charge may get deposited on the surface of
the plastics produced during processing.
• This may cause severe damage to the
products & equipments.
• It may cause accumulation of dust.
• The accumulation of static charge can be
minimized by the use of antistatic agents.

49. Antistatic Agents
• EX:
– Amines
– Quaternary ammonium compounds,
– Phosphates,
– Esters,
– Polyethylene glycol esters

50. Slip & Anti block Agents
• Slip : Reduces coefficient of friction- They
are high molecular weight fatty alcohols
• Amount (0.05 – 0.2% )
e.g. For film of 25 micron 0.01% of
Oleamide

51. Slip & Anti block Agents
• Anti block Agents : Prevent adhesion
between the film surface
Amount (0.05 – 0.2%)
e.g.
– Calcium Carbonate in PVC film
– Metal Salts
– Fatty Acids
– Natural & Synthetic Waxy Materials

52. Selection of Slip & Anti block Agents
• Must not spoil optical properties.
• Must not interface with the adhesion ink to
film.
• Must not prevent the sealing of film.
• Must be colour less
• Must be odour less
• Must be non toxic

53. Nucleating Agents
• Aiding transmission of white light in Plastics
• Forms large nos. of nuclei & reduces the
size of spherulites.
e.g.
– Sodium, Potassium, Lithium benzoates.
– Inorganic Powders – Clays, Silica Flour

54. Optical Brighteners
• It makes a mask over the yellowness formed
during processing.
• Optical Brighteners are organic substance
which absorb UV radation
e.g.
– Benzosulphonic & Sulphonamides
derivatives.
– Vinylene bisbenzoxazoles.
– 4-alkyl-7-dialkyl amino coumarins.

55. Optical Brighteners
• It makes a mask over the yellowness formed during
processing.
• Optical Brighteners are organic substance which absorb
UV radiations.
• Its also called as Fluorescent Whitening agent
e.g.
– Benzosulphonic & Sulphonamides derivatives.
– Vinylene bisbenzoxazoles.
– phenylcoumarins

56. Principles
• The optical brightening agents are capable of absorbing
invisible UV radiations (wavelength range 360 to 380 nm)
converting it to longer wavelengths & reemitting it as visible
blue or violet light.
• Thereby, the unwanted yellowish cast of substrate is
compensated & more visible light in the range of 400 to 600
nm is reflected than was originally incident, hence the
article appears whiter & brighter.

57. Objectives
• Improvements of the initial colours of plastics, which are
inherently often slightly yellowish.
• Production of brilliant white end use articles such as
packaging films, fashion goods & imitation leathers etc.
• Increase of the brilliancy of colored, & black pigmented
articles.
• The concentrations of 100-500 ppm for Thermoplastics,
special applications required exceeding 1000 ppm.

58. Mechanism of OB

59. Examples of Optical Brighteners
Trade name Chemical Name
Hostalux bis-benzoxazole
Uvitex bis-benzoxazole / bis-(styryl)biphenyl
Blankophor benzotriazole-phenylcoumarin

60. Colorants
Produces varieties of coloured polymers
properties :
1) hiding power
2) particle distribution
3) fastness to light, heat, chem.
e.g. Benzidine yellow, red 2B pigments,
Alumina hydrate, iron oxide .
Applications:
Packaging, domestic articles, space research ,
m/c switches, transportation
Colorants
Dyes (completely soluble)
Pigments (forms dispersion)

61. Colorants
Dyes (Soluble in Polymers)
»Impart brilliant transparent colour to
clear plastics
»Inorganic & Organic
» AZOS (,180 – 2000C) for brightness and
clarity
»Anthraquinone (AQ) –Good heat
transparent weathearibility
(Auto tube light)

62. Colorants
• Pigments (In-Soluble in Polymers)
– Inorganic
– Organic
Inorganic Pigments :
• Titanium dioxide - White
• Cadmium sulphide - Yellow orange
• Lead chromate - Yellow orange
• Chromium oxide - Green
Organic Pigments :
• Benzidese – Yellow orange
• Copper phthalocyanine -Blue
• Chlorinated copper phthalocyanine
• Aniline black - BLack

63. Selection of Colorants
• Heat Stability
• Disperse ability
• Light fastness
• Chemical Inertness
• Opacity or transparency

64. Ultraviolet Light Absorbers
• Detected by
– Loss in Tensile Properties
– Discolouration
– Brittleness
• EX:
– Black in any form : Carbon Black, Black dye,
Black paints
– Benzophenones – for PE, Polyesters
– Benzotriazoles – for PS, Polyesters

65. UV STABILIZERS
• UV light  280-400nm  polymers unstable
• To overcome this UV stabilizers are used.
Classification-:
1)UV absorbers: Hydroxy benzophenones
2)UV quenchers: Piperidines
3)Pigment: carbon black
Applications -:
1) carpenting outdoor/seatings
2) Acrylic coating used on outdoor sign boards
3) Light diffusers
4) Used in outer liners of HMHDPE

66. Impact modifiers
• To upgrade physical properties of polymer to the extent
prescribed by consumer, the additives added to polymers are
called as strength (impact) modifiers.
• They impart breakage resistance, rigidity, ease of post
fabrication, strength to sheets
• The strength imparted depends on time & temp conditions of
processing .
• Rigid PVC for prolonged outdoor exposure needs IM, similarly
epoxy & polyester thermosets require impact modifiers.

67. Impact Modifier
• Enhance the impact properties of certain
brittle polymers so as to use in the field.
e.g.
– Chlorinated polyethylene, EVA are used for
PVC.
– SBR is used for polystyrene material.
– EPDM is used for PP ( Bumpers)
– Acrylic rubbers for Poyamides.

68. Fire/Flame retardants
• Polymers being organic compounds burn or
decompose on exposure to fire, generates toxic
fumes, smoke.
• Two techniques: 1)use fire retardant raw material.
2)use fire retardant additives.
e.g. inorganic :zinc borate
halogenated :chlorinate paraffins
applicable to polymers to be used in mines,
automobiles, air vehicles, railways, etc.

69. Flame Retardants
• Plastics + Fire –free radical formation
combines with Oxygen – CO – CO2
• Application : Automobile, Aerospace,
Electrical,Transportation,Building,Furnit
ure, TV cabinet

70. Flame Retardants
• Prevent Combustion by
– Insulate
– Creating endothermic cooling reaction
– Coating the product
• EX: - Aluminium trihydrate ( Nylon)
– Antimony trioxides (ABS)
– Chlorinated Paraffin
– Zinc borate
– Halogen Compounds
– Phosphorous acid esters ( PA,POM,FRP)
– Nitrogen Compounds

71. Blowing Agents
• Blowing agents are also known as
foaming agents. Upon heating liberate
Gas
• Are used to produce porous polymers
i.e. cellular/foam plastics.

72. Blowing agent
• Polymeric foams preparation(2 ways)
1) mechanical/physical
2) chemically
• substances called blowing agents, which on heating
decompose giving N & CO2
• Rigid PVC,ABS,Polystyrene, polyolefins being chief
consumers.
Applications:
mattresses, pillows, insulation, foam pipes for
non-p conditions.
e.g.para toluene sulphonyl hydrazide.

73. Blowing Agents
Physical Blowing agents: Nitrogen & CO2
inert gas- Low cost, No solid residue
Trichlorofluromethane – PU foam
Pentane and Heptane - PS foam
Chemical Blowing agents: High temp, Azo
Dicarbonamide decompose on heating to
produe free radicals and N2 gas

74. Blowing Agents
• EX:
– Ammonium bi carbonates
– Sodium bi carbonates
– Azo Di carbonamide
– Azo bis formamide
– N-nitrogen Compound
– Sulfonyl Hydrazides

75. THANK YOU