Rubber and Plastics 4

7/29/2019 Rubber and Plastics 4

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Rubber and PlasticsFormulations for Food Contact

Dr. Mike Zumbrum, Maztech, Inc.

Dr. Roger Avakian, PolyOne Corp.


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Outline{ Introduction: Polymer Parameters

{ Example Formulations{ Impact of Additives

{

Optimizing Formulations{ Applications

{ Conclusions

{ Acknowledgements


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Polymer Parameters{ Chemical Composition

{ Molecular Weight & Distribution{ Stereochemistry

{

Topology{ Morphology

{ Additives

2010 Thomas C. Ward


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Important Energies to Consider

Intermolecular Intramolecular

t

g+

g-

Chain Stiffness and Bond Rotation

Hydrogen Bonding in Polyamides 2010 Thomas C. Ward


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Microstructures of Chemical Composition

2010 Thomas C. Ward


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Molecular Weight Distribution

http://openlearn.open.ac.uk/mod/resource/view.php?id=196637


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Effects of Stereochemistry:Geometric Isomers of Polyisoprene

2010 Thomas C. Ward


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Trans-Polyisoprene

2010 Thomas C. Ward


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Additional Stereochemistry:

Tacticity of Polymers

2010 Thomas C. Ward


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Effect of Tacticity on Glass Transition

Temperature (Tg) of Polyacrylates

2010 Thomas C. Ward


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Topology of Polyethylene

HDPE

LDPE

LLDPE

2010 Thomas C. Ward


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Thermoset Network Topology

2010 Thomas C. Ward


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Morphology of Polymers

Tm Tg

2010 Thomas C. Ward


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Spherulitic Morphology of PET

20

Microphase Separated Morphology of


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Microphase Separated Morphology of

Styrene Butadiene Block Copolymer

PR Lewis and C Price, Polymer, 13, 22 (1972)


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Morphology of Impact Modified Nylon

IM1/Compatibilizer Only IM1

Smaller Impact Modifier Size

Gives Better Impact in this System


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Polymer Parameters{ Chemical Composition

{ Molecular Weight & Distribution{ Stereochemistry

{

Topology{ Morphology

{ Additives


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21CFR177.2600i. ElastomersEPDM, Silicone, NR

ii. Vulcanization Materials

i. Vulcanizing AgentsSulfur

ii. Accelerators/RetardersTMTM, DiCUP

iii. ActivatorsStearic Acid

iii. AntioxidantsBHT, TNPP (21CFR178.2010)

iv. PlasticizersDioctyl phthalate

v. FillersATH, TiO2, SiO2, carbon blackvi. Colorants

vii. Lubricants

viii. Emulsifiers

ix. Miscellaneousblowing agents


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{

Optimizing Formulations{ Applications

{ Conclusions

{ Acknowledgements


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Example Formulations

Thermosets:

z Platinum silicone

z EPDM

Thermoplastics:z Styrenic block copolymer (TPE)

z Polypropylene

z PET


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Platinum Silicone Formulation{ Vinyl Siloxane

{ Fumed Silica{ Hydride Siloxane

{ Ethynyl Cyclohexanol

{ Platinum Catalyst

70 %

25 %5 %

0.1 %

15 ppm

{ Base Polymer

{ Reinforcement{ Crosslinking

{ Inhibitor

{ Hydrosilylation

Vinyl Siloxane Hydride Siloxane


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EPDM Formulation63 %

31 %(15 %)

0.6 %

3 %0.9 %

0.9 %

0.3 %

0.5 %

{ EPDM

{

Carbon Black{ Oil

{ Stearic Acid

{ Zinc Oxide{ Sulfur

{ TMTM

{ Mercapto BZ

{ Antioxidant

{ Base Polymer

{

Reinforcement{ Extender

{ Co-activator

{ Activator{ Curative

{ Accelerator

{ Co-accelerator

{ Heat Stabilizer

Could have 20 different ingredients


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Thermoplastic Elastomer (TPE)

Styrenic Block Copolymer{ S-EB-S

{ Polystyrene

{ Polypropylene

{ Mineral Oil

{

BHT{ Alphamethyl styrene

58 %

22 %

Optional

16 %

0.3 %3.4 %

{ Base Polymer

{ Reinforcement

{ Toughness

{ Softness

{

Stabilizer{ Processing

Broad range of properties available depending upon composition

Composition called out in FCN from Kraton


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Polypropylene Formulation{ Polypropylene

{ Phosphite{ BHT

{ Nucleant

99 %

500 ppm1000 ppm

0.5 %

{ Base Polymer

{ Processing stabilizer{ Co-stabilizer

{ Crystallization

Thermoplastic formulations have fewer ingredients.

Materials sold as produced from resin manufacturer.


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PET Formulation{ Polyethylene Terephthalate

{ Phosphite

{ Anthranilic Acid derivative

{ (Amorphous Nylon & cobaltcatalyst) in masterbatchs

{ Anthraquinone dye{ Benzotriazole

99 %

100 ppm

200 ppm

(3 %)

50 ppm1000 ppm

{ Base Polymer

{ Stabilizer

{ Scavenger

{ Oxygen scavenge

{ Colorant{ UV Absorber

Very low levels of additives todayDepends upon application (ie. bottles)


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{ Optimizing Formulations

{ Applications

{ Conclusions

{ Acknowledgements


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Types of Additives{ Stabilizers/Antioxidants (21CFR178.2010){ Modifiers (plasticizers){ Colorants

z Organic (phthalocyanine, anthraquinone)z Inorganic (TiO2, carbon black)

{

Mold Releases & Slip Agentsz Euracamides, waxes, silicones

{ Flow Aidsz Low MW olefinsz Glycerol monostearatez Vulcanized vegetable oil

{ Conductive materials

{ Others


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Why Use Stabilizers/Antioxidants?{ Protect Polymer During:

z Dryingz ProcessingExtruding; moldingz In Use Exposurez Long Term Exposure

{ Protect Against:z

Thermo-oxidative Degradationz Long Term Heat/UV Radiationz Harmful Effects of Gamma Radiation Sterilizationz Gas Fading reactions with NOx

{ Common Stabilizersz Hindered phenolsz PhosphitesTNPPz Thio-estersz Aluminum Trihydrate (ATH) Al2O3

.3H2O

BNX 1010

TNPP


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Temperature Range for Stabilizers

Hindered

Amines

HinderedPhenols

Thioesters

Phosphites

http://www.ampacet.com/usersimage/File/tutorials/Antioxidants.pdf


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Modifiers(Typically Used at Levels >1 wt.% to ~40 wt. %)

{ Plasticizers

z

Dioctyl phthalatez Mineral oil

{

Impact Modifiersz rubbery material

z core shell

z functionalized EPDMz HIPSpolybutadiene


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Testing to Identify Extractables &

Leachables{ Test Conditions: Some StandardMany Custom

z Usually 24 hrs at fixed temperature using:z

Distilled Waterz 5% Acetic Acid

z 95% Ethanol or hexane to simulate Fatty Foods

{ Sometimes a Synthetic Olive Oil is Used

{ Analytical Methods{ Gravimetric

{ Organic analysis: ChromatographyGC & LC

{ Elemental analysis: ICP & Ion Chromatography


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Concerns about Leachables{ Residual Monomers

z Styrene (Suspect Carcinogen)z Bis-phenol A (Suspect Endocrine Disrupter)

z VCM (Vinyl Chloride Monomer) Carcinogen

{ Modifiersz Plasticizers

{ Phthalates (Suspect Endocrine Disrupters)

z Mercaptothiazole (Suspect Carcinogen)

{ Stabilizersz TNPP tris(nonyl phenyl) phosphite (Endocrine

Disrupter)


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Nanotechnology{ Extractability of Inorganic Particulates

{ Carbon Nanotubesz Fibrous Irritant like asbestos?

{ Do Nanomaterials penetrate cell walls?

{ Can they be inhaled, or consumedinternally from packaging

{ End of Life{ Where do they go upon combustion,

land burial, disposal at sea?


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New Approaches

{ Naturally Occuring Stabilizers

z Vitamin E

z Glycerol Monostearates

{

Bound Stabilizers{ Inorganic Stabilizers

z Non-migrating, e.g. nano Zn Oxide

{ Nanoplatelets

z Synthetics: -zirconium phosphate


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{ Applications

{ Conclusions

{ Acknowledgements


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Optimizing Formulations{ Structure

z Chemical Composition, MW, stereochemistry

z Fillersz Crosslinkers

z Additives

{ Processz Shear/Dispersion

z Coupling Agents

z Temperature/time

{ Propertiesz Modulus, strength, fatigue life, compatibility

Properties

Structure Process


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Extrusion and Compounding

16 mm Twin Screw Extruder Sigma Blade Dough Mixer

Example of a Optimized Mixture Design


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Example of a Optimized Mixture Design

COM-A COM-B COM-A COM-B

F.M.=aComA+bComB+c*IM1Impact=a*ComA+b*ComB+c*IM1

Typical Response Surface Plot


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Typical Response Surface Plot

X1 ( 1 . 0 0 )

X2 ( 1 8 . 0 0 )

X2 ( 4 . 0 0 )

X3 ( 1 5 . 0 0 )

X3 ( 1 . 0 0 )

0 . 0 0 0

0 .250

0 .500

0 .750

1 .000

Desirability

X1 ( 1 5 . 0 0 )


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{ Applications

{ Conclusions

{ Acknowledgements


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Hygienic Envelope Gaskets


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Hygienic EPDM Gaskets


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BPE Standard Test Conditions

Dynamic Application: Effects of Fatigue on


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Dynamic Application: Effects of Fatigue on

EPDM Diaphragm

FailedNew

Effects of Thermal & Chemical Cycling on


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Effects of Thermal & Chemical Cycling on

Fluoropoymer Lined Hose

Severe Cracks

Smooth,

Straight,

New Liner

Failed HoseNew Hose


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Conclusions

{ Start with the polymer parameters

{ Additives are often necessarywatchfor leachables

{

Optimize by understanding structure-property-process interrelationships

{ Understand the application

requirements


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Acknowledgements

{ Tim Rugh 3-A Standard

{ Roger Avakian PolyOne Corp.

{ Tom Ward VA Tech

{ Bob Elbich Exigo Manufacturing

Documents

Rubber and Plastics 4