Transcript Phthalate Plasticizers CE 435 Introduction to Polymers Brian Amato Sarah Karl

Phthalate Plasticizers
CE 435 Introduction to Polymers
Brian Amato
Sarah Karl
Carla Ng
Timeline (history)
First
Phthalates
Plasticizer Introduced
1860
1930
European
IARC Re-classifies Parliament calls
DEHP
DEHP as nonfor alternatives
Declared
carcinogenic
to phthalates
Carcinogenic
1980’s
1998
2001
Outline
Introduction
 A Plasticizer
Timeline
 Theory
 What are
Phthalate
Plasticizers

(and why do we care)?

The Plasticizer
Market
Health
Concerns
Science and
Industry
Response
Government
Positions
Health or
Hype?
Conclusions.
Introduction
What is a plasticizer?
 Where are they commonly found?

General Definition
A Plasticizer is a polymer additive.
 Effect on polymer properties: an
important distinction from other
additives.
 Increases polymer flexibility, elongation
or workability.

Types of Plasticizer (I)
 Internal

vs. External
Internal plasticization occurs via
chemical interactions.
 Copolymerization
plasticization.

is one type of internal
External plasticization occurs via
physical interactions.
 External
is the most common: cost, ease
of processing.
Types of Plasticizer (II)
 Primary
vs. Secondary
 Primary
Plasticizer affects resin
properties.
 Secondary is a “Plasticizerplasticizer”: used to increase the
effectiveness of the primary
plasticizer.
Plasticizers In PVC





Cling-film for food
packaging.
Medical devices:
blood bags, IV bags,
tubing.
Vinyl floors.
Synthetic leather.
Electrical Cables.

Toys: teethers for
infants and Ernie’s
favorite bath-time
companion.
Plasticizers All Around Us
 Non-PVC
 Liquid
Uses
plasticizers used in coating to
protect car chassis.
 Paints.
 Printing Inks.
 Adhesives.
Plasticizer Theory
Three Mechanisms:
•
•
•
Lubricity Theory
Gel Theory
Free-Volume Theory
Lubricity Theory
Assumes the rigidity of the resin (pure
polymer) arises from “intermolecular
friction.”
 Plasticizer molecules are introduced on
heating.
 At room temperature, these molecules
act as lubricants for the polymer chains.

Gel Theory
Resin-resin interactions occur at
“centers of attachment.”
 Plasticizer molecules break these
interactions and masks the centers from
each other, preventing re-formation.
 This theory is not sufficient to describe
interaction– should be combined with
Lubricity Theory.

Free-Volume Theory
Free volume: “internal space” available
in the polymer for the chains to move.
 This volume increases sharply at the
glass transition temperature, Tg.
 Plasticizer is meant to decrease the
glass transition temperature, imparting
increased flexibility to polymer at room
temperature.

Choosing Your Plasticizer
 Effectiveness Considerations
 How Much Plasticizer Necessary
 Interaction Parameters: Our Friends Flory
and Huggins.
 Application Considerations:
 Temperature Range
 Degree of Flexibility Desired
 Phthalates:
the #1 Choice for PVC
Plasticizer Market

Yearly Plasticizer Production



Plasticizers are the largest class of polymer
additives produced.
Global volume of 10 billion lbs in 1999
$5 billion value with 2-3% yearly market growth.
<1% of Phthalates produced are used in
children’s toys.
 10% are used in medical applications.

Phthalate Plasiticizers

What are they Chemically Speaking?
A Phthalate ester derived from phthalic
acid by an esterification reaction.
 Mechanism: phthalic acid to phthalate ester

H
Phthalate Plasiticizers

Properties
Colorless
 Oily liquid ( like vegetable oil)
 Ester odor
 High boiling point
 Inert, and very stable over long periods

Phthalate Plasiticizers


Types:
DEHP (Di(2-ethylhexyl) phthalate)
 Structure
Phthalate Plasiticizers

Properties of DEHP
Insoluble in H2o
 Soluble in mineral oil, hexane, most organic
solvents
 Easily dissolved in bodily fluids, such as saliva
and plasma.
 Boiling point: 386.9oc
 Density: 0.9732 g/L
 Molecular weight: 390.5618 g/mol

Phthalate Plasiticizers

Uses of DEHP:
Used in medical devices
 Toys
 Pacifiers
 Vinyl Upholstery
 Food containers
 Table cloths
 Shower curtains
 Raincoats ( and the list goes on……..)

Phthalate Plasiticizers

DINP (Diisononyl Phthalate)
 Structure
Phthalate Plasiticizers

Properties of DINP
Insoluble in H2O
 Soluble in most organic solvents
 Boiling point: not available
 Density: not available
 Molecular weight: 418.6 g/mol

Phthalate Plasiticizers

Uses of DINP:

Replaced DEHP in toys when initially
determined to be carcinogenic.
Uses of DEHP in Medical
Devices

Phthalates (DEHP) in Medical Devices:




Blood Storage Bags
IV Bags
Catheters
Dialysis tubing
 Benefits:

Why is DEHP used?



Cost efficiency
Safety
Resists kinking
Uses of DEHP in Medical
Devices
Long shelf life
 Transparent
 Withstands high pressures without leaking
 Withstands both freezing and steam
sterilization
 Collapse when empty, therefore they do
not have to be injected with sterile air to
replace the blood or fluid being withdrawn.

Uses of DEHP in Medical
Devices

Other convincing reasons
DEHP contributes to the extended storage
of red blood cells.
 Doubles shelf life compared to other
plasitcizers.
 5-7 billion patient days of exposure without
any reported adverse health effects

Health Concerns

DEHP is a Carcinogen?


Studies in the early 1980’s on the effects of DEHP
on rodents by U.S National Toxicology Program
and International Agency for Research show
carcinogenic effect.
Scientific papers give rise to concerns of reduced
sperm counts from phthalates, due to the
endocrine disruption theory.
Health Concerns

Concerns Abated:
The International Agency for Research on
Cancer changes reverses its position on
DEHPs Carcinogenic effects.
 Endocrine disruption theory in regards to
DEHP disproved.

Health Concerns
Research with laboratory rats suggests
sexual developmental issues by
reducing fetal testosterone levels
 Testosterone levels were reduced to
female levels
 How does this relate to Humans? Or
does it?

Health Concerns
Tests were performed on Monkeys who
are primates like humans
 DEHP & DINP were both used and
yielded no noticeable biological or
physical responses to treatment
 Species specificity?

Health Concerns
Should this give manufacturers of Phthalates
a clear conscience? Not Necessarily
 Researchers in Puerto Rico claim that
premature breast development of young girls,
thelarche, may be the result of Phthalate
exposure
 8 out of every 1000 girls suffer from this
condition

Other Health Concerns Aside
From Medical

Plasticizers and Infants:


Toys and Teethers
Plasticizers in Food:

Packaging Film
Industry/Science Response

In response to concerns about the safety of
plasticizers, industry and science worked
together to study the effects and disseminate
information.




Toy manufacturers voluntarily replaced phthalates
and, in some cases, PVC.
European Chemical Industry Council (CEFIC)
forms EMSG, ECPI.
ECPI conducts joint research with Chemical
Manufacturer’s Association (CMA) in the U.S.
The EPA, the Vinyl Institute and NIH provide
information to consumers about their rights and
the safety of phthalate-containing products.
Government Decisions

Europe



Several European nations banned the use of
phthalates in toys.
International Agency for Research on Cancer
classifies DEHP as carcinogenic, then reverses
their decision in February of 2000.
As late as April of this year, the European
Parliament calls for the use of substitution
products. Seek to eliminate environmental effects
of phthalates.
Government Decisions

United States


The EPA regulates the amount of DEHP and DINP
in the environment. They are listed as toxic
chemicals subject to reporting requirements under
the Pollution Prevention Act (PPA).
The FDA has issued no warnings on phthalate
plasticizers, and does not consider them to be
carcinogenic. No action has been taken by the US
government in issues outside of the environmental
aspect of phthalates. Any consumer product
industry response has been voluntary.
Health or Hype?
Evaluating the Positions of the Major Players

Greenpeace


Have come out against the Vinyl industry in
general, due to their belief in the toxicity of
chlorine.
The Vinyl Institute

Seeks to disseminate information about the
importance of vinyl products in our life and the
evidence that they are not harmful to humans.
Alternatives to Plasicizers

Benzoates
 Citrates
 DINA
 EPZ (Edible Plasticizer)
 TXIB Plasticizer (hard oil)
 168 Plasticizer
 DEHP is still used in medical devices although
alternatives are being explored
Conclusion
Michael Fumento of the Hudson Institute:
“If your child eats toys, phthalates are the
least of your worries!”
 Conflicting evidence about the effects of
phthalates in humans and the environment.
 Possible consequences for the food chain.
 In the end, it is up to consumers to educate
themselves and make informed decisions.

References
1.http://www.fda.gov/cher/minutes/plast10108
99.html
2.http://www.pirg.org/masspirg/enviro/sw/pvc
3.Abbott, Barbara D. (2000). “The Plasticizer
Diethylhexyl Phthalate Induces
Malformations by Decreasing Fetal
Testosterone Synthesis during Sexual
Differentiation in the Male Rat.”
Toxicological Sciences 58, 339-349
4.Ackley, David C. (2000). “Effects of Di-isononyl
Phthalate, Di-2-ethylhexyl
Phthalate, and Clofibrate in Cynomologus
Monkeys.” Toxicological Sciences 56,
181-188
5.Carraher, Charles E. Polymer Chemistry: an
Introduction 4th Ed. (1996) Marcel Dekker, Inc. NY,
New York 424-426
6.Durodie, Bill “Poisonous Propaganda, Global Echoes
of an Anti-Vinyl Agenda.” Competitive Enterprise
Institute, July 2000
7.http://www.cei.org
8.Christensen, Jackie Hunt. Toxic Toy Story.
Mothering. Sept. 1998 p38 (1)
9.O’Mara, Peggy. Winning the Fight Against
PVC. Mothering. March 1999 p35 (1)
10.Raloff, J. Girls May Face Risks from
Phthalates. Science News. Sept 9, 2000 v158
ill p165
11.Ullman’s Encyclopedia of Industrial
Chemistry, Vol A20 pp439-451, VCH
Publishers, Inc, 1992
12.Woodyatt, K.G. Lambe, K.A. Myers, J.D.
Tugwood and R.A. Roberts, “The Peroxisome
Proliferator (PP) response element upstream
of the human CoA oxidase gene is inactive
among a sample human population:
significance for species differences in
response to PPs.” Carcinogenesis, vol.20 no.3
pp.369-371, 1999
13.Zacharewski, T.R., M.D. Meek, J.H.
Clemons, Z.F. Wu, M.R. Fielden and J.B.
Matthews, “Examination of the in vitro
and in vivo estrogenic activities of eight
commercial phthalate esters.”
Toxicological Sciences, Vol. 46, pp.282293, 1998