# Tires glass transition temperature



## Doug Huffman (Apr 25, 2015)

While everyone else was watching the Turkey Bowl after Thanksgiving Dinner, I was studying tire Butadiene Rubber - BR - and Styrene-Butadiene Rubber - SBR - physical chemistry related to _glass transition temperature_ *Tg*. My intention was to find a collection of tire models and their various Tg. I did not find that.

I did find a number of textbooks and manufacturers***8217; formularies on control of Tg. Only this empirically derived Tg data (curves below) was clear (to me) about the detail between Tg and physical characteristics of a tire.

I did come to understand that Tg is not an abrupt crystalline transition as it is in metal***8217;s Brittle Ductile Transition Temperature (from my fracture mechanics training). It is clear, it was made clear, that Tg is the middle of the transition curve of temperature versus the modulus, ***8216;stiffness***8217;; somewhere just to the left of -50°C in the illustration***8217;s below- again empirically acquired.

Perkins-Elmer cut an anonymous tire into samples and tested them. Tg = -50°C seems an extreme winter cold performance tire for it not to have been identified as such. So I wonder about the commonsensical use of ***8220;glass transition temperature***8221; in commodity tire discussions and if it is not marketeering puffery.

https://www.bimmerfest.com/forums/attachment.php?attachmentid=828979&stc=1&d=1542807892

https://www.bimmerfest.com/forums/attachment.php?attachmentid=829279&stc=1&d=1542977526

The device used to acquire this data was a PE DMA-8000 Dynamic Materials Analyzer.


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## Autoputzer (Mar 16, 2014)

There's a blurb on TireRack.com about summer, ultra-high performance tires having the potential for being damages if loaded below +20F.

As with much of your stuff...


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## Doug Huffman (Apr 25, 2015)

Autoputzer said:


> There's a blurb on TireRack.com about summer, ultra-high performance tires having the potential for being damages if loaded below +20F. As with much of your stuff...


Your commercial puffery link is as precise and effective as usual. Paraphrasing Abe Lincoln; it is better to not address an unfamiliar topic and be thought ignorant than to write witlessly and remove all doubt.

A tire can be damaged at 100°F.

A picture is said to be worth a thousand words. Thus, a nonsense pictures is equivalent to your thousand words of nonsense.


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## Autoputzer (Mar 16, 2014)

My engineering job was sort of backwards. Most engineers start with a stack of paper and end up with a piece of hardware or software. In my job, we started out with a piece of hardware or software, and ended up with a stack of paper. There were some exceptionally good engineers in the group I worked in. The problem was having them interface with just about the entire remainder of the human species.

One of the engineers was particularly skilled, achieving "guru" status. He was a non-supervisory GM-14 before retirement. After retirement, he came back as a contractor at TWICE his GM-14 pay, and he was still the biggest bargain in our budget. All of the information he produced was technically complete and correct. The problem was that it was unusable information. The people who paid literally millions of dollars for a 300 page report would call up with a question. The engineering guru's answer was always 'It's in the report." It was, buried somewhere in the 300 pages. I was better with Microsoft Word than with Lab View. So, my job one year was to take the guru's 300 pages of technically correct and complete, but useless gibberish, and translate it into English and organize and filter it into *usable *information. In every case, the really important stuff in those 300 page reports could be condensed into somewhere around three pages.

Your original post is a perfect example of what I dealt with in my job: probably technically correct information, but totally *useless* information. From the footnote in your posts, this seems to be a common occurrence in your life.


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## Doug Huffman (Apr 25, 2015)

LOL. It is useful to me to know, to be sure, that babble about Tg is just that, babble and marketeering. You may share in my study and knowledge or you may ignore me (please).


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## Doug Huffman (Apr 25, 2015)

*More Tg v. Mers cis-SBR, E-SBR, L-SBRs, SBR 40% Styrene*

https://www.bimmerfest.com/forums/attachment.php?attachmentid=829315&stc=1&d=1543011592


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## Doug Huffman (Apr 25, 2015)

I have never taken formal organic chemistry to learn the naming conventions. Poly-_cis_ 1,4 butadiene was breaking my brain to understand. The _cis_ means ***8216;same side***8217;, contrasted with _trans_, ***8216;opposite side***8217;. I looked that up and remembered it from something else.

I***8217;m at my PharmD daughter***8217;s for Thanksgiving, so I asked her about the numbering. First, I have been confused by the inconsistent use of commas ***8216;,***8217; and dots ***8216;.***8217;, thinking it is European versus Imperial numerical notation. No. We got out her O-Chem textbook for me to learn that they are commas and numbering the location of the == bonds in the polymer, here butadiene.

We began her postgraduate studies together. I had recently retired and was refreshing to go back to maths. Her undergraduate was BA Arts with no maths exposure. We refreshed our maths together at the local tech college. She went on to her earned doctorate, and I to advanced analysis at the local liberal arts college.


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## Autoputzer (Mar 16, 2014)

Let me know when you get to the part of how cold my summer, high-performance Michelin PSS's and Conti DW's can be without: dangerous performance degradation, and damage to the rubber. We're moving north next year, where the record low temperature was -24F.


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## Doug Huffman (Apr 25, 2015)

I live at N 45.4° but out in Lake Michigan that moderates our weather and temperatures. My VW TDI started at -35°F, cold soaked while we were at the local theater. It grumbled but started and ran fine. 

I have had my X5 on CPO OE Stone Bridge***8217;s Duelers for three winters and they did just fine. Last year the snowplow didn***8217;t have to plow my road for no kids for the school bus to pick up.

If I am trying to make any point, and NOT to da Putz, it is that damage does not occur merely by use in temperatures < Tg, and that -25°F is not likely < Tg for any commodity tire. As I have tried to illustrate above with an anonymous tire with Tg ~< -50°C and a factor of two increase in modulus stiffness.


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## Doug Huffman (Apr 25, 2015)

I just reviewed a whole slough of patents/applications to see no patented Tg >0°


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## Doug Huffman (Apr 25, 2015)

*Structure of L-SBR and consequent Tg. All below -10°C*

Note Firestone Duradene 715 SBR Tg = -35°C - not necessarily tire rubber.

https://www.bimmerfest.com/forums/attachment.php?attachmentid=829377&stc=1&d=1543072674


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## Doug Huffman (Apr 25, 2015)

*Firestone Duradene SBR Tire Applications*

"Duradene***8482;
Duradene***8482; Styrene Butadiene Rubber: Tire Applications. Duradene***8482; solution styrene butadiene rubbers are uniquely suited for use in tire compounds, from tread to sidewall to innerbody." (https://www.firestonepolymers.com/duradene_tires.asp)
https://www.bimmerfest.com/forums/attachment.php?attachmentid=829381&stc=1&d=1543073890

*The highest Tg here is -22°C*


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## Doug Huffman (Apr 25, 2015)

*Are amorphous solids elastic or plastic or glass?*

Non-pro review

https://phys.org/news/2018-12-amorphous-solids-elastic-plastic.html

"A stability-reversibility map unifies elasticity, plasticity, yielding, and jamming in hard sphere glasses" Science Advances (2018)

Open source

http://advances.sciencemag.org/content/4/12/eaat6387


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## Ridin'Dirty (Apr 13, 2017)

Beer solves everything! :thumbup:

BONUS: formula of aluminum sulfate


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