LDPE & HDPE (1 Viewer)
- Thread starter lilkatie
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Will Hunting
Member
They're kinda handy. I'll run you through...
HDPE - High density polyethylene(ethene). Its structure is crystalline, or linear, meaning that it is tougher and more rigid than other varieties of polyethylene. Its average molecular weight is also quite high, giving it greater hardness and higher colligative properties (MPT/BPT) than others.
LDPE - Low density polyethylene(ethene). Its structure is amorphous, or branched, meaning that it is flimsier and has greater flexion than other forms of polyethylene. Its average molecular weight tends to be lower than that of HDPE, hence, making it better suited to applications requiring less tensile strength in a material.
You might want to take note of Ultra High Molecular Weight Polyethylene(ethene), too. It's an extremely sturdy form of plastic used in bullet-proof vests as a substitute for Kevlar and in ice-skating rinks (as the ice), its hardness owing to its size in molecular terms.
Catch you later!
HDPE - High density polyethylene(ethene). Its structure is crystalline, or linear, meaning that it is tougher and more rigid than other varieties of polyethylene. Its average molecular weight is also quite high, giving it greater hardness and higher colligative properties (MPT/BPT) than others.
LDPE - Low density polyethylene(ethene). Its structure is amorphous, or branched, meaning that it is flimsier and has greater flexion than other forms of polyethylene. Its average molecular weight tends to be lower than that of HDPE, hence, making it better suited to applications requiring less tensile strength in a material.
You might want to take note of Ultra High Molecular Weight Polyethylene(ethene), too. It's an extremely sturdy form of plastic used in bullet-proof vests as a substitute for Kevlar and in ice-skating rinks (as the ice), its hardness owing to its size in molecular terms.
Catch you later!
thunderdax
I AM JESUS LOL!
The actual syllabus dot point says "outline the steps in the production of polyethylene as an example of a commercially and industrially important polymer"
this refers more so to LDPE where by:thunderdax said:
initiation, propogation, termination
u need to know in detail... (500K, 1000-3000 atm pressure, presence of initiator)
the process to manufacture HDPE is zeigler natta process, requiring relative low temp/pressure (60C/ 2-3 atm) and catalysts (trialkylalumnium + titanium (III) chloride)