2014 Processing Techniques Seminar

Plasticizers in the

Polyurethane Industry

Presented by:

Mick Funderburg

Principal Technical Services Representative

Eastman Chemical Company

mfunderburg@eastman.com

Topics to cover

What plasticizers are and traditional uses of plasticizers

How and why plasticizers are used in polyurethanes

Benefits and limitations of plasticizer use

What phthalates are and why they matter to you

Regulatory issues and timeline with plasticizers

What to look for in a plasticizer supplier

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What is a plasticizer?

Plasticizer – a substance or material incorporated in a material (usually a plastic or elastomer) to increase its flexibility or workability

Will likely affect the viscosity

of the formulation

Lowers the temperature of a second-order transition • Such as the glass transition temperature (Tg)

Lowers the elastic modulus of the end product

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How plasticizers work

Plasticizer theories

Lubricity theory

Gel theory / Mechanistic theory

Free volume theory

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Traditional uses for plasticizers

Flexible PVC

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Traditional uses for plasticizers

Adhesives and sealants

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Internal plasticizers

Flexible segments incorporated into the polymer chain

Adds flexibility and toughness

Examples:

• Polyvinylacetate + ethylene = vinyl acetate ethylene (VAE)

• ABS (acrylonitrile butadiene styrene)

• Block copolymers (SIS, SEBS, etc.) Components of

ABS polymer

chain

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Internal plasticizers

Polyurethanes also considered examples

• Crystalline “hard” segments

Diisocyanates + low MW hydroxyl compounds

• Amorphous “soft” segments

Oligomers / diols

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External plasticizers in polyurethane systems

Why use an external plasticizer?

• Regulate rheology

Lower viscosity of reaction medium

Reduce polymer viscosity

• Regulate thermal properties

• Regulate mechanical properties

Improve softness/increase flexibility

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Plasticizer use in Polyurethane systems

Benefits

Viscosity reduction - easier compounding

Cost reduction – plasticizers cost less than base polymer

and allow for higher filler loading

Reduced glass transition temperature – lower tensile

strength, hardness and increased elongation

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Plasticizer use in Polyurethane systems

Limitations

Concentration limited to less than 30% by weight

Compatibility must be tested with specific formulations –

no one size fits all plasticizer

Migration issues lead to decreased performance over

time

Some monomeric plasticizers do not hold up under

extreme conditions and polymeric plasticizers are

expensive

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Plasticizer selection parameters

Compatibility

Efficiency

Permanence

Processability

Regulations

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“Like solvates like”

Capable of forming a homogenous mixture

Plasticizer does not react chemically with other system

components

Polarity

Hydrophilic / lipophilic balance

How to determine

• Theoretical: Calculate solubility parameter

• Experimental: Tg suppression, clarity of polymer system

Compatibility parameters

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Efficiency parameters

Efficiency: tool to compare plasticizers

The amount of plasticizer needed to obtain a specific value for a specific performance property

Some comparative tests for polyurethane elastomers • Tensile properties

• Elongation properties

• Resiliometer

• Glass transition temperature (Tg)

• Durometer hardness

• Viscosity of blend

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Permanence parameters

Permanence: a measure of how long the plasticizer will

stay in the polymer matrix and function as intended

Factors affecting permanence of a plasticizer

• Molecular weight

• Compatibility

• Environment

Tests to determine permanence

• Volatility

(neat plasticizer or in polymer matrix)

• Extraction resistance

• Migration resistance

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Processability parameters

Plasticizer compatibility with the polymer affects the

workability of the system during processing

So, plasticizers can affect

• Viscosity

Melt viscosity

Processing temperature

• Moldability

• Calenderability

• Vacuum forming characteristics

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Additives for better mold definition

Standard formulation

(based upon TDI-terminated

polyester prepolymer /

aromatic diamine system)

Same formulation with

addition of 5% Eastman

TXIB™ formulation additive

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Classes of plasticizers Adipates

Azelates

Benzoates

Citrates

Epoxidized oils

Ethers

Fatty acid esters

Glycerol esters

Glycols and glycol esters

Hydrocarbons

Paraffins (halogenated)

Pentaerytheritol esters

Phosphates

Phthalates

Polyesters

Soy and other oil derivatives

Stearates

Sulphonamides

Sulfonates

Terephthalates

Terpenes and derivative

Trimellitates

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What is a phthalate?

The term “phthalate” conventionally refers to

ortho-phthalates

• ortho-phthalate = phthalate

• meta-phthalate = isophthalate

• para-phthalate = terephthalate

DEHP

DEHI

DEHT

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Why phthalates matter

Migration out of polymer leads to environmental

questions

Metabolism of phthalates creates a stable monoester,

which is blamed in some toxicology studies

Risk assessments disagree about the extent of the risk

surrounding phthalates

Increasing regulatory attention being given

by many agencies to ortho-phthalates

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Regulatory Shift to Non-Phthalates (ECHA)

European REACh regulation • Four targeted ortho-phthalates (DEHP, DBP, DIBP, BBP) in Europe’s

official process to ban substances in commerce except for “authorized” uses.

• Very few “authorized” uses for phthalates are expected.

• All non-authorized uses will be banned effective Feb 2015.

• Except for authorized uses, no products containing the four listed phthalates will be allowed to be manufactured or imported in EU after this date.

ECHA ban on DINP and DIDP in toys • Late-August 2013 ECHA confirmed that the ban on use of DINP and

DIDP in toys and childcare articles is permanent.1

• They performed an open review of the ban from 2008 and accepted comments and reviewed the latest data and studies.

• Ultimately they stated that adverse effects from exposure to young children by mouthing items containing DINP and DIDP could not be ruled out, so the ban was confirmed.

Regulatory Shift to Non-Phthalates (U.S.)

US Environmental Protection Agency’s Chemical Action Plan

• Includes IRIS reassessments of phthalates, adding the phthalates to the

Chemicals of Concern list, and a Design for the Environment (DfE)

alternatives assessment that includes 96 possible alternatives.

• Alternatives assessments on: DEHP, DBP, BBP, DIBP, DIDP, DINP,

DnOP, DnPP

US Consumer Product Safety Commission (CHAP)

• Under the 2008 CPSIA law, DEHP, DBP, and BBP were permanently

banned for toys and childcare articles.

• DINP, DIDP, and DnOP were temporarily banned for use in toys and

childcare articles, subject to further review.

• The CHAP is performing that review and an alternatives assessment for

all six of the phthalates.

What to look for in a plasticizer supplier

Reliable source of supply

Technical formulation and analytical support

Varied product line to fill any need

Knowledge of regulatory issues and changes

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Session summary

What plasticizers are and traditional uses of plasticizers

How and why plasticizers are used in polyurethanes

Benefits and limitations of plasticizer use

What phthalates are and why they matter to you

Regulatory issues and timeline with plasticizers

What to look for in a plasticizer supplier

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Thank you!