OCR AS Salters Chemistry F332 - Wednesday 23rd May 2012 1:30pm

can anyone tell me why this is addition and not condensation if it's made from 2 different monomers? (answer is addition)
and is co-polymer a condensation polymer or are these two different things?

we only cover one type of polymerisation in this unit, and it is addition. So whenever it asks you what type it is, it is always addition.

Reply 581

3raindrops

Original post by Kreayshawn

can anyone tell me why this is addition and not condensation if it's made from 2 different monomers? (answer is addition)
and is co-polymer a condensation polymer or are these two different things?

For F332 We don't even need to know about condensation polymerisation. Its always going to be addition, the yield is 100%.

So both are addition polymers. Just open up double bond.

Reply 582

laseine

ok i have time to do ONE MORE past paper, which would you recomend? i have done both 09 and jan 2012

anyone?

Reply 583

Kreayshawn

Original post by dongonaeatu

we only cover one type of polymerisation in this unit, and it is addition. So whenever it asks you what type it is, it is always addition.

thanks! you've been super helpful since yesterday.
thanks 3raindrop too.

Reply 584

tbZ Falcon

Original post by laseine

ok i have time to do ONE MORE past paper, which would you recomend? i have done both 09 and jan 2012

anyone?

If you have the OCR Salters revision guide, the exam style questions in there are very helpful.

Reply 585

dongonaeatu

Original post by Kreayshawn

thanks! you've been super helpful since yesterday.
thanks 3raindrop too.

its ok

Reply 586

Tikara

Original post by laseine

the "another polymer made by accident" came up in a past paper... june 09... it was PTFE/Teflon, bakelite, poly(ethyne) and "conducting polymers"

how would you define an "addition polymer"??

and HDPE would be thermo plastic because there aren't covalent cross links between chains? same for LDPE? the only difference is HDPE is straight chain polmer and LDPE is branched chain?

I think an addition polymer is a polymer made from an addition reaction of many monomers.

Poly(propene) I'd put for another addition polymer - but this is at the end of the article anyway.

Thanks very much, i'll just remember PTFE :smile:

and equation two (first one on page 4) is that a propagation reaction as there are radicals on both sides and the next equation a termination as there are no radicals on the right?

So both LDPE and HDPE are thermoplastics? has HDPE got a higher bioling/melting point? (how would you explain this?)

I think the 4/5 marker (question 5) will be something broad about radicals, what they are and how they are formed.

thanks everyone for the help!

Reply 587

username970812

Original post by Kreayshawn

can anyone tell me why this is addition and not condensation if it's made from 2 different monomers? (answer is addition)
and is co-polymer a condensation polymer or are these two different things?

I don't think condensation polymerization ever comes up. My teacher didnt even teach us it. I don't know what condensation polymerization is but, if there is 2 different monomers it a co-polymer nothing else. They are not linked. When they talk about polymer reactions it's 99% of the time Gonna be addition

(edited 11 years ago)

Reply 588

chocolate102030

what is the name of the ketone produced from ethene and benzaldehyde

Reply 589

chocolate102030

or do we not need to know that

Reply 590

username970812

Original post by Kirity

Wait I'm confused. In the revision book it says a thermoset is a polymer that doesn't deform when heated. But it's produced by covalent cross linking between polymer chains.

But it's says Hdpe do not deform when heated fitting the definition of thermoset. But they don't have covalent cross linking?

are they a thermoset?

;( help?

Reply 591

Tikara

When do you use half-headed curly arrows? just when showing how radicals form?

Reply 592

chocolate102030

Original post by Tikara

When do you use half-headed curly arrows? just when showing how radicals form?

you use them to show the movement of ONE electron, full headed is to show the movement of TWO electrons

Reply 593

chocolate102030

Original post by chocolate102030

what is the name of the ketone produced from ethene and benzaldehyde

somebody help?!

Reply 594

laseine

Original post by Tikara

I think an addition polymer is a polymer made from an addition reaction of many monomers.

Poly(propene) I'd put for another addition polymer - but this is at the end of the article anyway.

Thanks very much, i'll just remember PTFE :smile:

and equation two (first one on page 4) is that a propagation reaction as there are radicals on both sides and the next equation a termination as there are no radicals on the right?

So both LDPE and HDPE are thermoplastics? has HDPE got a higher bioling/melting point? (how would you explain this?)

I think the 4/5 marker (question 5) will be something broad about radicals, what they are and how they are formed.

thanks everyone for the help!

ok cool thanks

yes it's propgation then termination, have you read this page, it's really helpful

http://www.chemguide.co.uk/mechanisms/freerad/polymtt.html

though i think it's a bit too indepth but it helps me to actually understand the whole thing

Reply 595

dongonaeatu

Original post by chocolate102030

somebody help?!

Dont think we need to know that.

Reply 596

matty b

Original post by Kreayshawn

can anyone tell me why this is addition and not condensation if it's made from 2 different monomers? (answer is addition)
and is co-polymer a condensation polymer or are these two different things?

a copolymer is a polymer, formed by addition polymerisation, that has more than one type of monomer,

Reply 597

Tikara

Original post by chocolate102030

what is the name of the ketone produced from ethene and benzaldehyde

I'm trying to find it :/

but hey guys, I just found a PDF of the article the advance notice was taken from: http://www.rsc.org/images/InfoChem_Jan2005_Plastic_fantastic_tcm18-217681.pdf

dunno if it has more info or less, but it has pictures :P