1 / 3

Organic mechanisms

Organic mechanisms. Low density poly(ethene) , LDPE The manufacture of low density poly(ethene) is carried out at very high pressure (1000 – 3000atm) at a temperature of about 500K Ex: R – O-O – R -> 2RO free radical formation RO + H 2 C = CH 2 -> R – O – CH 2 – CH 2 propagation

wardah
Download Presentation

Organic mechanisms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Organic mechanisms Low density poly(ethene) , LDPE • The manufacture of low density poly(ethene) is carried out at very high pressure (1000 – 3000atm) at a temperature of about 500K Ex: R – O-O – R -> 2RO free radical formation RO + H2C = CH2 -> R – O – CH2 – CH2 propagation R – O – CH2 – CH2 + H2C = CH2 -> R – O – CH2 – CH2 – CH2 – CH2 Termination takes places when two radical combines

  2. Low density poly(ethene) , LDPE • An average polymer molecule with about from 4 x 103 to 4 x 104 carbon atoms with many short branches which affect both degree of crystalize and density of material

  3. High density poly(ethene) , HDPE • HDPE is produced by polymerizing ethene at a low temperature ( 350K) and pressure ( 1 – 50atm) using a Ziegler – Naha catalyst. The catalyst is a suspension of titanium (iv) chloride together with an alkyl aluminium compound (Al(C2H5)3). • The result of polymer consist mainly of linear chains with very little branching. This gives it a higher density 0.96gcm-3 and a more rigid structure as the chains can fit together more closely. It is used to make containers and pipes

More Related