|WikiProject Chemicals / Core||(Rated B-class, High-importance)|
- 1 Box
- 2 Solvents
- 3 Goofy sentences
- 4 Oxidized polypropylene
- 5 Please help: electrical conductivity of polypropylene
- 6 Practical applications cleanup and expansion
- 7 Discussion of merger of PP-R into Polypropylene
- 8 Stationary folders or stationery folders?
- 9 Health / leaching
- 10 Use for irrigation pipe
- 11 PP adhesive
- 12 History
- 13 Food contact availability
- 14 Vinyl?
- 15 Health / Leaching section needed in the main article
- 16 Tactile properties
- 17 PP-R
- 18 This should be included in the recycling section.
- 19 Sales revenues for 2019
- 20 Noteworthiness of PP use for model aircraft?
- 21 Assessment comment
- 22 Clarification of wording needed
The melting point is : ~ 165°C Glass transition is : ~ -12°C
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)
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)
Depends what you mean by "use safely" - do you mean "safe" in the sense of non-harmful to the user, or "safe" in the sense of non-aggressive to polypropylene? If its the latter, then methanol would certainly not attack PP. StanPomeray (talk) 16:52, 26 November 2008 (UTC)
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)
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 22.214.171.124 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 126.96.36.199 (talk) 19:32, 17 March 2007 (UTC).
Please help: electrical conductivity of polypropylene
Please tell me the figure of the electrical conductivity of polypropylene.
- There exist polypropylene capacitors, by the way. The Types_of_capacitor page claims that polypropylene capacitors are low-loss, high-voltage and resistant to breakdown.188.8.131.52 (talk) 22:08, 22 October 2012 (UTC)
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.
Discussion of merger of PP-R into Polypropylene
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)
Stationary folders or stationery folders?
In the Paka thama 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)
Health / leaching
What are the health effects--i.e. is there leaching of any organic compounds (including additives) when this material is used for applications that hold hot beverages? Badagnani (talk) 16:53, 1 August 2008 (UTC)
There shouldn't be any leaching into hot beverages. PP used for the construction of items such as cups would not contain any plasticisers, and although there may be some antioxidant added, if its soluble in PP then its likely to be insoluble in water - PP is highly non-polar, water is highly polar. StanPomeray (talk) 16:52, 26 November 2008 (UTC)
Use for irrigation pipe
The section on Practical Applications could include the widespread use of flexible polypropylene pipe for agricultural irrigation piping. In arid countries such as Australia, black "poly pipe" is seen snaking across the landscape in many parts of the outback, preferred over other polymers because it is relatively unaffected by ultraviolet radiation. It has been used since the 1960s to supply stock watering points, and has greatly extended the carrying capacity of many grazing farms. Peter Bell (talk) 09:34, 3 September 2008 (UTC)
i need to know is there any adhesive that works well on PP?? i mixed poly styrene with solvent and it can be used as adhesive for polystyrene material, but i can't find the right solvent for polypropylene.... —Preceding unsigned comment added by Ithankyou (talk • contribs) 05:42, 13 February 2009 (UTC)
Yes, this page says that 2-part epoxies work with polypropylene but they don't. The only adhesive I've found that works with this plastic is 3M(TM)Scotch-Weld(TM)Structural Plastic Adhesive DP8005.Warturo64 (talk) 04:49, 24 October 2010 (UTC)
There seems to be a either a conflict of timeline or lack of information regarding the history section. Apparently,  developed a crystalline form of PP in 1951, 3 years before Natta. Please look into the matter. —Preceding unsigned comment added by 184.108.40.206 (talk • contribs)
It seems the error lies in the fact that while PP was "in essence" developed by Mr. Banks, it was Natta who discovered process of polymerizing Isotactic PP. here is the reference for the information:  —Preceding unsigned comment added by 220.127.116.11 (talk) 18:49, 17 July 2009 (UTC)
Perhaps include a discussion of the discovery of Banks/Hogan (which predates that of Ziegler/Natta) in addition to any relevant extensions of the science/technology contributed by Ziegler and Natta. In addition, the 30-year history of patent litigation is interesting and possibly relevant here. See . — Preceding unsigned comment added by 18.104.22.168 (talk) 16:08, 8 April 2013 (UTC)
Food contact availability
How it is with food contact availability? Does products made from PP require FDA (or any other) certificate/approval? —Preceding unsigned comment added by Bexsro (talk • contribs) 15:06, 26 August 2009 (UTC)
- Yes. All food grade containers require FDA approval and must meet their stringent requirements on a variety of things. There are also additional certifications that can be done at the manufacturers request by other independent organizations.User7984 (talk) 21:06, 11 November 2009 (UTC)
The article reads "Like most other vinyl polymers...", which would seem to imply PP is a vinyl polymer. I'm not an expert, but PP has a methyl group (CH3) where per vinyl, vinyl has a CH2, so it would seem that PP is not vinyl, no? 22.214.171.124 (talk) 09:09, 12 September 2009 (UTC)
Health / Leaching section needed in the main article
Polypropylene is favoured for children's toys and anecdotally (but am sure there are research references!) is liked by some autistic-spectrum individuals on the basis of its soothing waxy feel. Some mention should be made of tactile aspects. 126.96.36.199 (talk) 09:34, 8 December 2015 (UTC)
- Need a high quality reference to insert something like that. Its pretty innocuous stuff, not to mention quite insoluble. One should be wary of chemophobia.--Smokefoot (talk) 13:56, 8 December 2015 (UTC)
This should be included in the recycling section.
http://ourworld.unu.edu/en/plastic-to-oil-fantastic/ —Preceding unsigned comment added by 188.8.131.52 (talk) 20:06, 25 August 2010 (UTC)
Sales revenues for 2019
Noteworthiness of PP use for model aircraft?
This somehow doesn't seem important. This section may have been contributed by a model airplane fanatic who became excited by some new polypropylene parts, and chose the polypropylene Wikipedia page as the means to share that enthusiasm with the world. What volume of the global PP production goes to model airplanes? 184.108.40.206 (talk) 22:02, 22 October 2012 (UTC)
The comment(s) below were originally left at several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section., and are posted here for posterity. Following
|Comment(s)||Press [show] to view -->|
|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.
Last edited at 12:57, 4 March 2007 (UTC). Substituted at 03:12, 30 April 2016 (UTC)
Clarification of wording needed
The article includes the sentence "At elevated temperature, PP can be solved in of low polarity solvents (e.g. xylene, tetralin and decalin)." "Solved in of low polarity solvents" may mean something, but I'm not sure what. — Preceding unsigned comment added by 220.127.116.11 (talk) 23:04, 13 October 2016 (UTC)