Additives for polymer: plasticizer, filler, lubricant

Slides presents additives used in polymer

1. WELCOME

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

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

4. 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.

5. 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%)

6. 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

7. 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.

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

9. 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

10. 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

11. Lubricants or Flow Promoters

•External Lubricants
•Internal Lubricants

12. 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.

13. 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

14. 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.

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

16. 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.

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

18. 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.

19. 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.

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

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

22. 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

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

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

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

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

27. Fibrous Fillers & Reinforcement
Reinforcing fillers are those which enhance
the mechanical properties like :
•Tensile Strength
• Modulus
• Hardness of a polymer compound.
The product become stiffer and stronger
than the base polymer.

28. Fibrous Fillers & Reinforcement
Glass Fibres –
Increase(Tensile, Compressive,Flexural )
Strength ,Increase rigidity, creep resistance
hardness and decrease thermal expansion
co-efficient, elongation at break.
Minerals such as talc, calcuim carbonate,
mica – increases the compound rigidity,
improve the temperature resistance and
reduces shrinkage & warpage.

29. 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

30. 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

31. 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.

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

33. 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

34. 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

35. 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

36. 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.

37. Colorants
Dyes (Soluble in Polymers)
»Impart brilliant transparent colour to
clear plastics
»Inorganic & Organic
» AZOS (,180 – 200
0
C) for brightness and
clarity
»Anthraquinone (AQ) –Good heat
transparent weathearibility
(Auto tube light)

38. Colorants
•Pigments (In-Soluble in Polymers)
–Inorganic
–Organic

39. Colorants
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

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

41. 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

42. Impact Modifier
•To 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

43. Flame Retardants
•Plastics + Fire –free radical formation
combines with Oxygen – CO – CO
2
•Application : Automobile, Aerospace,
Electrical,Transportation,Building,Furnit
ure, TV cabinet

44. 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

45. 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.

46. 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.
•EX:
–Ammonium bi carbonates
–Sodium bi carbonates
–Azo Di carbonamide
–Azo bis formamide
–N-nitrogen Compound
–Sulfonyl Hydrazides

47. Master Batches,Additives & Reinforced Compounds
Material Supplier
Master Batches S.C.J. plastics Ltd. New
Delhi
www.scjindia.com
Master Batches &
Reinforced
Compounds
Aalekh Polymers (P)
Ltd.
8/30, Kirti Nagar New
Delhi =15
Ph. No. 25195193
Polymer additivesFine organics Bombay
022-25116900-02

48. THANK YOU