isat test 2 ch. 9: plastics, polymers, & waste

what kind of plastics can you NOT recycle?

3, 4, 6, AND 7

what does the number on the recycling symbol mean?

shows what type of plastic it is

PET

HDPE

PVC

LDPE

PP

PS

OTHER

downcycling

process of recycling waste into new product of lower quality than original

• park benches, carpets, fleece jackets

• most plastics that gets recycled is this

  • water bottle not likely to come back as another water bottle

plastic

lightweight, durable, & cheap (blessing & curse)

does plastic decompose?

NO

• degrades to finer pieces & accumulates

microplastics

tiny particles too small to see

• get eaten by animals & humans

ocean garbage patches

not real patch, areas where debris collects (pacific area)

• small pieces, often below surface

what country is the leading importer of plastic scrap?

malaysia

what are options you can do when it comes to disposing items?

1. reduce

2. reuse

3. recycle

4. recover energy (burn)

5. dispose (if no other option)

what should you do when you want to avoid creating potential waste?

reduce

what should you do it you can’t avoid the waste?

reuse

what should you do if you can’t reuse the waste?

recycle/compost

• bottle deposit system for reusable bottles

what should you do to the waste if you can’t recycle?

recover energy (burn safely)

• cradle-to-cradle/closed loop/downcycling

what should you do with the waste if you can’t burn it?

dispose safely in landfill

what are plastics mostly made of?

hydrocarbons

• energy from combustion → mandated in europe

landfill disposal

designed & engineered to keep water out & keep waste in

• doesn’t always work

how do we know what’s best?

• life-cycle-assessment (LCA)

• consider environmental impacts

• account from cradle-to-grave

what environmental impacts should we consider?

• production

• transport/handling

• use

• re-use

• disposal

polymers

large molecules made up of long chains of atoms (covalent bonds)

• chains of MONOMERS

monomers

smaller molecule units that are chained together

macromolecules

very large molecules with 1000s of atoms

what are plastics ALSO made of?

POLYMERS

cellulose

woody plant matter

• glucose monomers linked together

what do natural polymers include?

• cellulose

• starch

• latex (rubber)

• keratin (hair wool, nails, horns)

• proteins

• DNA

what are polymers made out of?

hydrocarbons (mostly from oil)

how is polyethylene made?

addition polymerization

• free radical that initated reaction

what does a HIGH density polyethylene dictate?

not branched, uniform (stronger & more rigid)

• 30% recycled

• milk bottles

what does a LOW density polyethylene dictate?

branched, won’t stack tightly

• ~3% recycled

• carrier bags

big 6 polymers definition

THERMOPLASTIC POLYMERS

• can be melted & reshaped

• degrade over time

what ARE the big 6 polymers?

1. LDPE (4)

2. HDPE (2)

3. PVC/V (3)

4. PS (6)

5. PP (5)

6. PETE/PET (1)

what is the only difference in monomers?

SINGLE FUNCTIONAL GROUP

polymer structure impacts properties

• head to tail, head to tail

• head to head, tail to tail

• random

what kind of polymer is a polyester compound?

PET (1)

what is polyester made of?

a condensation polymerization reaction

• polyester bond is formed

• water is produced