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Question regarding: HDPE and LDPE production (1 Viewer)

AnimeX

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So, to my understanding for LDPE an initator molecule (a peroxide) is required, in combination with relatively low pressure and temperatures.
On the other hand HDPE, requires a zieler-natta catalyst, accomponied by high pressure and temperature.

So my questions are"

does LDPE require any catalysts?
does HDPE require an initiator molecule?
do both LDPE and HDPE follow the initiation, propagation and termination steps?
 

Menomaths

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So, to my understanding for LDPE an initator molecule (a peroxide) is required, in combination with relatively low pressure and temperatures.
On the other hand HDPE, requires a zieler-natta catalyst, accomponied by high pressure and temperature.

So my questions are"

does LDPE require any catalysts?
does HDPE require an initiator molecule?
do both LDPE and HDPE follow the initiation, propagation and termination steps?

LDPE requires high pressure and high temperature (this results in significant chain branching, making it low density)
HDPE requires low temperature and low pressure along with the catalyst zeigler-natta
 

bedpotato

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I thought LDPE required high pressure and temperature, while HDPE requires much lower pressure and temperature.

This is what I've learnt:
1 and 2: no. For LDPE, the initiator activates the process by opening up the double bond of an ethylene molecule. For HDPE, the catalyst does this and the polymerisation occurs on the surface of the catalyst.
3. Yes.

not 100% sure on this though :s
 

AnimeX

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LDPE requires high pressure and high temperature (this results in significant chain branching, making it low density)
HDPE requires low temperature and low pressure along with the catalyst zeigler-natta
I thought LDPE required high pressure and temperature, while HDPE requires much lower pressure and temperature.

This is what I've learnt:
1 and 2: no. For LDPE, the initiator activates the process by opening up the double bond of an ethylene molecule. For HDPE, the catalyst does this and the polymerisation occurs on the surface of the catalyst.
3. Yes.

not 100% sure on this though :s
my bad you guys are correct
 
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LDPE requires high pressure and high temperature (this results in significant chain branching, making it low density)
HDPE requires low temperature and low pressure along with the catalyst zeigler-natta
Is saying that HDPE requires low pressure enough? Or should we provide a specific value/range?
 

Drsoccerball

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Is saying that HDPE requires low pressure enough? Or should we provide a specific value/range?
Doubt its required but i lost a mark because i said low and my teachers a douche sometimes when it comes to marking "so low temperature i could put it to absolute zero ?" So idk
 
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Doubt its required but i lost a mark because i said low and my teachers a douche sometimes when it comes to marking "so low temperature i could put it to absolute zero ?" So idk
because the Ahmad Shah revised, perfected and edited, notes say "This process uses only a few atmospheres of pressure" so i don't think it would be zero
 

Drsoccerball

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because the Ahmad Shah revised, perfected and edited, notes say "This process uses only a few atmospheres of pressure" so i don't think it would be zero
I didn't say it was 0... I said in another question i didnt mention exact temperature and lost a mark.
 

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