Polymer Additives

Question 1

What are polymer additives?

Answer 1

Are HPV chemicals = high production volume chemicals.
Additives are not chemically bound to the matrix, hence can be released again with high temp.
Several reasons to have additives in plastic:
• blødgørende/emolient. Plastiziser
• Flameretardants
• coloring/pigments
• (Stabilizer/preservative)
• addtives that increases the strength of the material. UV-protection
• odour
• to make it food-safe
• anti-oxidants
• biodegradable plastizer
• biocides. avoid biofilms. nasty compounds. other countries put on the surface of buildings.
when rain go with water and to environment.
• linked to uv light
• static collect dust.
• added for process of making plastic. blow some gas in for bow material.
• molding process, things come out nicely
• take some volume. save costs. cheap, sand. physical strength. di-atomer (kiselalger). part of
the geological material.
• does not crack when physical streanght
• re-inforcement and fillers closely related. focus here is stronger material.

ASSESSMENT OF THE COMPOUND:
• PBT: It is T, but not PB
• HPV: yes
• POP: not a persistent compound!
• SVHC: Yes.

Question 2

What is the chemical structure of polymer additives?

Answer 2

CHEMICAL STRUCTURE:
• aromatic ring
• ester group

Question 3

Can you talk a bit about the polymer additives in relation to transport?

Answer 3

• Main source: antropogenic transport from the production site to the use site.
• As they are not bound to the matrix, they will dffuse to the surface of the product and be
released.
• Transport in air, water, and animals is unlikely. Air=degrade. Water= not soluble.
• Transport by animals: not bioaccumulate.
• Co-transport: can sorb to aerosols.

Question 4

Can you talk a bit about polymer addtivies (pftalates) in relation to distribution?

Answer 4

Distribution
• Where will the compound distribute?
• Gets more hydrophobic with increasing alkyl-chain. Similarly, the water solubility decreases
with increasing alkyl chain.
• Vapour pressure decreases by more than four orders of magnitude with increasing alkyl chain
length
• Kh (Henry’s law constant)
lower molecular phthalates: low rate of volatilization (1.2E-7 – 8.8 E-7 atm m3/mole)
Higher molecular phthalates (expect BOP): significant rate of volatilization (1.7E-5 to 5.5E-4
atm-m3/mole).
• Vapour-aerosol:
Short alkyl chains: mainly present in the water phase.
Longer alkyl chain: more associated with aerosols.

Question 5

Can you talk a bit about polymer additives (pftalates) in relation to transformation?

Answer 5

• Does not bioaccumulate in humans, can be matebolised in humans.
• Abiotic degradation:
hydrolysis only at slow rates.
Photodegradation dominant in the atmosphere, as they react with OH-chemicals.
• Biotic degradation:
Dominant in surface waters, soils, and sediments
Microbial degradation under both aerobic and anaerobic conditions. Aerobic conditions more
degradation occur.
The longer the alkyl chain length, the less the biodegradation.
Lower BCF values are reported for higher trophic levels i.e. that they don’t bioaccumalte that
much due to their more advanced metabolism.