1. by Michael Verhülsdonk 1167685
Plasticizers
by Michael Verhülsdonk

2. Content Introduction Functionality and theory
Overview of common plasticizers
Impact on processing
Problems
New developments

3. 1. Introduction: scope product: process:
increasing flexibility
process:
decreasing viscosity
Other properties can also be affected!

4. 1. Introduction: history
camphor as plasticizer for nitrocellulose
discovered by John Wesley Hyatt in 1869

5. 1. Introduction: supply global production capacity 2004: 5.5 Mt
increasing tendency (3.5% per year)
biggest production regions:
Asia
Eastern Europe
Latin America

6. Introduction: PVC biggest demand for plasticizers
up to 40% plasticizer

7. 2. Functionality and theory
two groups of plasticizers:
non-reactive
(no covalent bonding with polymer)
reactive
(forms covalent bonding with polymer)

8. 2. Theory: non-reactive blend of polymer and plasticizer
then processed (extrusion)
plasticizer keeps distance between polymer chains
reduction of intermoelcular forces
temperature resistance can be estimated from boiling temperature

9. 2. Theory: non-reactive
without plasticizer
with plasticizer

10. 2. Theory: reactive polymerization of monomer mixture
plasticizer monomers
actual monomers
forming a copolymer
reduction of inter- and intramolecular forces

11. 3. Overview of common plasticizers
phthalates
adipates, citrates, sbacates
fatty acid esters
oligomeric/ polymeric plasticizers
epoxies

12. 3. Overview: phthalates very efficient, low costs
most used plasticizers worldwide
approx. 80% of phthalates are used for PVC
Plasticizer
Global production capacity
DEHP
>50%
DINP
>10%
DIDP
>20%

13. 3. Overview: phthalates DEHP (Di-2-ethylhexyl phthalate)
also called DOP (Dioctyl phthalate)
relatively non-volatile under heat
good electrical properties
increases cold strength of rubbers
DINP (Diisononyl phthalate) and DIDP (Diisodecyl phthalate)
similar properties like DEHP

14. 3. Overview: adipates, citrates, sebacates
food approved
used for food packaging and containers

15. 3. Overview: fatty acid esters
used as viscosity depressants for pastes

16. 3. Overview: oligomeric/ polymeric plasticizers
polyesters of adipic acid
low migration/ volatility (boiling temperature >300°C)
also mixture of low and high Mw of same polymer kind possible
increase in polydispersity
decrease in viscosity
copolymers, e.g. DAP (Diallyl phthalate) as plasticizing monomer

17. 3. Overview: epoxies low migration good resistance against extrusion
can be used as pigment dispersant
recommended for food contact and medical products

18. 4. Impact on processing absolutly necessary for many processes
decreased viscosity
lower processing pressures required
can reduce energy costs e.g. for extrusion, injection molding
safer, cheaper
plasticizer can also work as lubricant
benefits for mold release

19. 5. Problems: emissions
plasticizer molecules can migrate to product‘s surface
processing emits plasticizers, e.g.
injection molding: 0,03%
coating: 2%
emitted plasticizer is absorbed by human beeings and environment

20. 5. Problems: risks to health
Phthalates! Aromatic compounds similar to hormones
can cause infertility, hormonal interferences, cancer
prohibition of phthalates for sensible products like baby toys and food packaging in the EU

21. 6. New developments
optimized particle size distribution and particel shape (by ‚Hydro Polymers‘)
greater efficiency, lower amounts
easy and more effective mixing

22. 6. New developments new blending technology (by ‚Velsicol Chemical‘)
improved flow behavior of benzoate esters
benzoate esters: great performance, hard to process
new blending technology could reduce this problems significantly

23. 6. New developments Hexamoll®/DINCH® (by BASF)
hydrogenated DINP, no aromatic character
similar properties to DEHP/DINP/DIDP
(good electrical properties)
(good cold strength) …

24. Thank you…
… for your attention!

25. Sources
Additives for Plastics Handbook, 2nd Edition, Elsevier Science Ltd., chapter 14.

26. Introduction
Plasticizers are additives for plastics or cellulosic with the purpose to make the plastic more flexible, either in the final product either for the processing of the plastic. Often, more properties than flexibility are affected when plasticizers are added to a plastic; e.g. lubrication or dispersibility of a pigment can be changed in both the negative and the positive way. The earliest discovered plasticizer working successfully is camphor, which has been added to nitro cellulose by John Wesley Hyatt in Only the application of plasticizers made it for many materials possible to compete in daily handling and industrial production, then and today. In 2004, worldwide plasticizer production capacity reached 5.5 million tons, with increasing tendency. Without plasticizers, many products would be very fragile due to their original rigidity.

27. Functionality and theory
In terms of chemical bonding, plasticizers can be separated into two groups.
Non-reactive
Classically, plasticizers are added to the polymer before being processed, i.e. the polymer granules are mixed together with the plasticizer and then heated and mixed again in an extruder. The plasticizer molecules placed between the polymer keep a distance preventing the polymer chains from strongly sticking together enabling the chains to slip across and through each other more easily. Most plasticizers are low-volatile esters, fatty oils or resins decreasing the plastic’s glass temperature (Tg). Their temperature resistance can be estimated by their evaporating point. Examining the plasticizer’s and polymer’s molecular structure can be helpful for finding a suitable plasticizer. For example, a polar polymer requires a polar plasticizer because the small plasticizer molecules are kept in the polymer matrix due to intermolecular forces like dipole-forces.
Reactive
On the other hand, some polymers are polymerized in presence of plasticizer monomers. Forming a copolymer, the plastic’s flexibility can be increased. Next to the intermolecular forces, also intramolecular forces become relevant. Copolymerically plasticized plastics can be very desirable especially for products whose plasticizer must not be separated from the polymer (e.g. by extraction).

28. Overview of common plasticizers
Phthalates
Because of their high efficiency and low costs, phthalates are the most common plasticizers worldwide. Approximately 80% of their production capacity is used for PVC. The most widely used phthalates are:
DEHP Di-2-ethylhexyl phthalate, also dioctyl phthalate (DOP)
DEHP’s portion exceeds 50% of global plasticizer demand
relatively non-volatile under heat
good electrical properties
increases cold strength of rubbers
transparent PVC products possible (good for medical use, e.g. blood bags)
DINP Diisononyl phthalate - more than 10% of global plasticizer demand - similar properties like DEHP
DIDP Diisodecyl phthalate - more than 20% of global plasticizer demand - similar properties like DEHP
Long-chained alcohols - e.g. DITDP Diisotridecyl phthalate - high temperature resistance (>100°C)
Dimethylcyclohexyl phthalate
automobile underbodies
good low temperature resistance

29. Adipates, citrates, sebacates
Because of their food approval, esters of adipic, citric and sebacic acid are often used for food packaging, containers and films. They provide also good low temperature flexibility.
Fatty acid esters
These liquid plasticizers can be used as viscosity depressants for pastes.

30. Oligomeric/ polymeric plasticizers
Usually, polyesters of adipic acid are used because of their low migration, low volatility (boiling temperature >300°C) and good extraction resistance. Another way to get enhanced flexibility is to mix short chained polymers with long chained polymers of the same kind. This results in a higher polydispersity, thus in a lower viscosity. Common applications are paints, cables and coated fabrics, e.g. for protective clothing, conveyor belts or adhesive films. They can be processed easily. After copolymerization, diallyl phthalate (DAP) increases the plastic’s hardness and chemical resistance; furthermore, it shows a high affinity to glass fibers.
Epoxies
Epoxies provide a good resistance against extrusion on the one hand, but also against migration on the other hand. They are good pigment dispersants and also recommended for food contact and medical products.

31. Impact on processing
Increasing flexibility of a plastic also implies a decrease of the material’s viscosity which is the more suitable term concerning processing technologies. Actually, this decrease in viscosity is desirable regarding required pressures e.g. for injection molding because operating becomes cheaper and safer. Some plasticizers also work as a lubricant making injection mold release easier. In addition to that, without plasticizers many polymers could not be processed at all.

32. Problems
The main reason for many discussions about compatibility and health issues is the fact that most plasticizers migrate out of the product. Then, they are transported to the environment. Depending on the type of plasticizer, these emissions can be harmful to health on the hand but also to nature on the other hand. For example, phthalates are classified to be potential toxic causing cancer, infertility and hormonal interferences. Therefore, phthalates are prohibited to be used in sensible products like food packaging or baby toys intended to be put into the mouth. According to studies, 69 mg phthalates per kg bodyweight per day cause damages to reproductive organs. However, average exposure is 2 – 4 µg per kg bodyweight per day. Nevertheless, substitutes are arrogated. Moreover, plasticizers can also be emitted by the process itself. For example, plasticizer losses of 0,03% have been observed for injection molding processes and 2% losses for coating processes.

33. New developments
Greater efficiency at lower levels can be obtained by optimizing the plasticizer’s particle shape and size distribution leading to an easier and more effective mixing process (by Hydro Polymers).
New blending technologies have been invented (by Velsicol Chemical) improving flow behavior of benzoate esters used to be high viscous. This could make the processing of these great performance plasticizers more worthwhile.
Further achievements are the replacement of potentially hazardous types of plasticizers (e.g. DINCH by BASF) and the reduction of leaching and migration.