Talk:Polypropylene
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Article Grading: The following comments were left by the quality and importance raters: (edit · refresh) Where the article reads: "MFI (Melt Flow Index) identifies the flow speed of the raw material in the process. It helps to fill the plastic mold during the production process. The higher MFI increases, the weaker the raw material gets." Perhaps it should read "MFI (Melt Flow Index) identifies the flow speed of the raw material in a stadard test; the MFI is an indicator of the effectiveness with which the raw material will fill a mould. Higher values of MFI indicate quicker mold filling but are generally associated with a weaker final product." This sentence needs to be rewritten "It also has Copolymer and Random Copolymer. Copolymer helps stiffness of the PP (Polypropylene). Random Copolymer helps transparent look." Instead of "Copolymer is more expensive than Homopolypropylene. Random Copolymer is even higher than copolymer PP." consider "Currently the Copolymer form is more expensive than the Homopolypropylene form with the random Copolymer form being the most expensive." - well something like that. |
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[edit] Box
The melting point is : ~ 165°C Glass transition is : ~ -12°C
Regards Gwizi
First of all, I wrote the relevant transition temperatures in Kelvin (more scientific). Precision to more than one K is not necessary. Or better, it is plainly wrong. Polymers, unlike small molecules, lack sharp transitions. And, are there any sources on the melting point? 173 Celsius seems a bit too much, I think it is closer to 160 Celsius.Ossoduro 22:14, 10 August 2006 (UTC)
[edit] Solvents
Does anyone know what solvents one can use safely while using polypropene tubes? I have read somewhere that one can use methanol.--Hannu 08:53, 23 May 2006 (UTC)
[edit] Goofy Sentences
The first section has some really confusing remarks in it such as this one: "Although it is less tough then HDPE and flexible than LDPE, it is much brittle than HDPE" I'm not sure off the top of my head but it seems to me like this was supposed to say, "Although it is not as tough as HDPE and not as flexible as LDPE, it is much less brittle than HDPE." Anyone care to clean up this sentence? I think maybee it needs more than just adding in some missing words though, I think it needs to be split up into three complete and seperate ideas.
The end of the section following MFI is fairly meaningless also. I'll try and peice it all together as soon as possible, but in the meentime any comments would be greatly appreciated. CoolMike 06:37, 22 November 2006 (UTC)
"Although it is not as tough as HDPE ... it is much less brittle than HDPE." does not make sense, as "tough" is the opposite of "brittle" - perhaps "stiff" is the right word (since the Young's modulus is mentioned earlier in the article)? I would change the sentence to "Although it is not as stiff as HDPE and not as flexible as LDPE, it is much less brittle than HDPE." Gingekerr (talk) 13:12, 9 February 2008 (UTC)
[edit] Oxidized polypropylene
1) The following external link was added to the article:
- Thermoelectric Superconductivity (1997), high electrical conductivity of oxidized polypropylene and its prospective use in thermoelectric devices
2) Later, anon 81.178.78.221 added the following comment:
- "(Very speculative/ an interesting but unreliable source)"
About the comment "unreliable source", it should be noted that the author of the above article (see link) is an old Ph.D., physics & electrical eng. (1953-54) of ancient Trinity, Cambridge, having a vast puslished number of peer-reviewed papers and physics books.
3) Later, editor ChemGardener removed the link with the comment:
- "remove external spam link and irrelevant link"
Well, I think we should give the opportunity to each reader having expertise on this field to be the judge of the validity of the theoretical research presented through the above link. Cheers. —The preceding unsigned comment was added by 213.58.99.84 (talk) 19:32, 17 March 2007 (UTC).
[edit] Please help: electrical conductivity of polypropylene
Please tell me the figure of the electrical conductivity of polypropylene.
Thank you,
kl
[edit] Practical Applications Cleanup and Expansion
I fixed some confusing grammar in the section on practical applications Also I just measured the melting temp of a dupont extrusion grade PP to be 163 deg C and Tg to be -11 deg C using DSC for a lab class. It is essential to recognized the variablity of these values I only tested one grade from one batch... another may be +- 5 deg.
[edit] Discussion of merger of PP-R into Polypropylene
See Talk:PP-R. H Padleckas 06:54, 20 September 2007 (UTC)
Merged PP-R into Polypropylene. The single reference in the PP-R article was irrelevant, and was deleted.Chimpex 01:21, 8 October 2007 (UTC)
[edit] Stationary Folders or Stationery Folders?
In the Practical applications section, reference to "stationary folders" suggests folders that do not move, whereas "stationery folders" would have something to do with writing materials. Looks like a typo to me, but I'm not in plastics. —Preceding unsigned comment added by Morenus (talk • contribs) 15:16, 18 March 2008 (UTC)
