Talk:Rubber elasticity

message: — Preceding unsigned comment added by Davidhanson471 (talk • contribs) 03:53, 3 December 2019 (UTC)

message: This comment pertains to an early version of the article.  The text that it refers to is now in section 'Historical approaches to elasticity theory'.Davidhanson471 (talk) 03:14, 18 December 2019 (UTC)
thread_title:  Arithmetic Problems 

message: I applaud the effort of D Hanson in updating this page with modern modeling.
The problems I see are 
1) lack of balance ... apparently Hanson's work is the only work that is not merely historical. References are to him, or before 1950. Really? Nobody else at all?
2) No distinction between general truths of rubber elasticity and the details found by Hanson for polyisoprene; e.g. no discussion of the ideal rubber 
3) A serious error in that dealing with polyisoprene (?cis 1-4 ? it is not clear) the word 'crystal' never appears.
It is generally agreed that the turn upwards in the stress-strain curve for this material at high strain and room temperature is caused by strain induced crystallization (SIC).  In this article (and Hanson's papers) it is said to be caused by elastic deformation of the chain.  This would happen in materials that do not crystallize but they generally fail before getting into this regime.
It is commonplace that molecular modeling does not capture crystallization in temperature regimes where it is experimentally seen; the space and time limitations of even modern computers do not include the nucleation events.  But this does not mean it does not happen.  I do not understand why the author does not restrict his model to the regions of strain or temperature where crystals do not form.  
4) The falling slope of the stress-strain curve at lower strains is associated with details of molecular motion. But at least some of it is simply due to using engineering stress when the sample is reducing in cross-section. Identifying deviations from neo-Hookean would be more relevant. 
5) A special region 1a is described in molecular terms and vaguely indicated in fig 1 as below 100% strain. The references show it to be a specially stiff region at up to 5% strain.  Is there any experimental evidence for this to exist?  It seems a simple experiment to do.
(~~i just wanted to say i originally wanted crossbows , slingshots and rubber bands under elasticity but rubber elasticity works, second i promise to have good faith just poor skilled at coding grammar and a external link is to a Wikipedia article as a alternative only because there was a error at the time with linking to a wiki page ~~  — Preceding unsigned comment added by Timpatalpostma (talk • contribs) 18:15, 31 December 2020 (UTC)
thread_title:  Serious problems with this page: 

message: I agree; the overview is deficient.  I will re-write it shortly.  
Davidhanson471 (talk) 17:27, 10 December 2019 (UTC)
thread_title:  Problem with article overview 

message: The editor has provided a valuable expansion of this section. There are two issues that should be addressed:  1. The equations should be numbered to facilitate discussions and 2. references should be added.  Also, as it stands, it is useful mostly to scientists and engineers specializing in polymer physics.  The article could benefit from additional text to motivate and explain the mathematical derivation.  A short paragraph at the beginning to provide a summary of the section for the casual reader would also be appropriate.  
Davidhanson471  —Preceding undated comment added 23:57, 10 December 2019 (UTC)
thread_title:  Comment on Freely-jointed chain model section 

message: At the request of the Wikipedia editor, I have rewritten the Lead In section to provide the reader with a better description of what is included in the article.Davidhanson471 (talk) 20:53, 20 December 2019 (UTC)
thread_title:  Rewrite of Lead In section 

message: First of all, profanity, even abbreviated as '----ed', has no place on a Wikipedia page.  The opening sentence 'Due to the flexibility of many polymers such as chained rubber, these solids are often highly elastic ' is at best misleading. Flexibility is not the source of elasticity; nylon filament is very flexible but not elastic. I have no idea what the author means by the term 'chained rubber' or 'polymeric solids joined in a network'.  The revision is indeed shorter but poorly written and less informative than the previous version.  Unless Wikipedia has a length limit on Lead In sections, I recommend going back to the previous version.  I also suggest that further discussions about this be carried out on the Talk Page.Davidhanson471 (talk) 19:41, 4 February 2020 (UTC)
thread_title:  Comment on Lead In section as revised 4 Feb., 2020  

message: I have restored the Lead In section to its previous version.  If you have suggestions for changes, please post a comment on this talk page.  Davidhanson471 (talk) 16:25, 5 February 2020 (UTC)
thread_title:  Comment on Lead In section original version restored 5 Feb., 2020  

message: Following the suggestion by editor C4356278 posted on 11/2019, the Lead In section was re-written, consistent with wikipedia guidelines, on 12/20/2019.  Since no further comments regarding the Lead In section have been posted on the Talk Page, I have deleted the C4356278 post requesting modifications. It appears to be no longer relevant and might invite another case of mischief. Of course further comments and suggestions for improvements are always welcome on this page.  Davidhanson471 (talk) 19:52, 12 March 2020 (UTC)
thread_title:  Comment on Lead In section posted by editor C4356278 Nov., 2019 deleted 

message: At the request of the Wikipedia editor, I have rewritten the Lead In section, reducing its length by about 40%.Davidhanson471 (talk) 19:47, 19 October 2020 (UTC)
thread_title:  Rewrite of Lead In section 

message: Just rubber bands and slingshots but if you want to expand it to catapults & crossbows your welcome , I know 
Second I know one of the links looks like it’s from another site it’s not I am a noob and was dodging a error bug 3DPrintingTimPostma (talk) 20:03, 31 December 2020 (UTC)
thread_title:  Please fit in elasticity applied into projectile usage where applicable 

message: Another point to add that’s pretty not mentioned so much is I think under physics when people think of elasticity they think of rubber bands or similar rubber materials as a projectile launcher 3DPrintingTimPostma (talk) 20:10, 31 December 2020 (UTC)
thread_title:  This should be merged as a elasticity category 

message: I have removed the banner requesting shortening the lead In section since this was addressed 10 Oct., 2020., Davidhanson471 (talk) 22:15, 9 January 2021 (UTC)
thread_title:  Rewrite of Lead In section 

message: Since it deals with the freely jointed chain theory, it is more appropriate to place it in that section.Davidhanson471 (talk) 17:10, 25 August 2021 (UTC)
thread_title:  Moved the reference to the paper by Buche et al. to the Historical Approaches section. 

message: "Elastomers have played a key role in the development of new technologies in the 20th century and make a substantial contribution to the global economy.[citation needed]" I have searched the web for some reference that could speak to this but have not found anything yet.  Since elastomers are present in so many technologies and products, e.g. automobile and truck tires and electronic devices like cell phones, I don't think that most readers would question the claim about economic importance.Davidhanson471 (talk) 17:37, 27 August 2021 (UTC)
thread_title:  Regarding the request for a citation to back up the 'grandiose' claim about the economic importance