Glass Transition Temperature

[@preciousamaechi689]

I must confess, this was explicitly done. I have fully understood the ideas behind glass transition and have made a copious notes out of this lecture.

[@PolymerWorld]

Thanks for the feedback. Glad this was helpful.

[@kusumshibaranjanibohidar5996]

I've an exam on polymer tomorrow and I can't explain how much your channel helped me. Thanks a lot. God bless you 😭❤

[@PolymerWorld]

Thanks for your feedback! Good luck for your future!

[@materialsworld4gate]

You can also watch here for Material Science XE Group study materials, Question Paper solution and preparation tips kzbin.info/www/bejne/p3qyfGaphs9rftU

[@panashematutu6218]

she got it all. she is the best polymer l've been tought with

[@PolymerWorld]

Thank you.

[@johnwithfiveos]

Saved me from a lot of hassle of my polymer exams, thanks

[@srinivasaraovaragani479]

Very well explained. It is very much useful in pharmaceutical industry for polymer coating. Can you please give details of available polymers Vs Tg in combination of different plasticizers ?

[@monikagupta7177]

nice work...

[@PolymerWorld]

Thank you.

[@muhammadkashan1441]

Ma'am you are doing great job but it's a request that if these videos were also available in Hindi/Urdu so it would be more easy to understand and focus on these lectures. Your channel is doing great work. More power to you. 👏👏

[@awwabisam4053]

Thank you a lot for your great explaination methode that cover all the aspect associated with polymer . 👏👏

[@PolymerWorld]

Glad it was helpful!

[@noanyobiseniss7462]

You should do the close captions as it is too difficult to grasp your lecture with the thick accent.

[@sohakhan6732]

Excellent presentation very informative 👌👍👍👍

[@sohakhan6732]

Below tg polymeric material is soft while above is hard? Plz mam justify this question

[@PolymerWorld]

Below Tg polymeric materials are hard due to no chain mobility whereas above Tg due to chain segment mobility polymeric materials are soft and rubbery.

[@dalveersingh1019]

Nice video

[@PolymerWorld]

Thanks for watching.

[@Dr.A.K6909]

supper mam, very easy to understanding ,thank you!!

[@PolymerWorld]

Thanks for watching the video!

[@rehanachand8345]

Please give us more vdo on polymer like their structure,properties relationship, and molecular motion in polymers

[@PolymerWorld]

Sure....will post more videos soon. Thanks for watching!

[@materialsworld4gate]

You can also watch here for Material Science XE Group study materials, Question Paper solutions and preparation tips kzbin.info/www/bejne/p3qyfGaphs9rftU

[@rutujasalunkhe2756]

Plz make video on flory huggis theory ..

[@PRADEEPKUMAR-kp9il]

really helpful

[@PolymerWorld]

Thank you.

[@Abdullah_Khaled]

Very informative, thanks very much

[@mpvg6103]

Easy to understand...

[@PolymerWorld]

Thanks for watching!

[@jaj2629]

Very nice.

[@barkataziz4212]

Excellent work , but plz upload more vedios on polymer .

[@PolymerWorld]

More videos are coming...Thanks for watching!

[@syeraakamal308]

hi, thank you so much for the vid, it helped me a lot ! i have one question, is it Tg(glass transition temperature) and softening temperature of the polymer is the same thing?

[@PolymerWorld]

Softening temperature and glass transition temperature are two different terms. Softening temperature is flow temperature of a polymer. Amorphous polymers are processed at softening temperature as amorphous polymers do not have melting temperature.

[@shahzadahmed5012]

Very nice explanation. Maam I have a question. Do we have Tg value of small molecule? If no then why?

[@PolymerWorld]

Small molecules or oligomers have very low Tg. Due to small chain size these molecules have mobility at very low temperature.

[@shahzadahmed5012]

@@PolymerWorld now got it. Thanks a lot Ma'am

[@inorite4553]

Ha! I'm taking a Polymers class too. Looks like you have yourself a new subscriber. Thank you

[@PolymerWorld]

Welcome. Thanks for subscribing.

[@Democratic_people]

very nice . thanks

[@kopiohui864]

Thank you a lot, really!

[@PolymerWorld]

Thanks for watching!

[@rishikuchadiya5203]

In chain braching , it is lowering the Tg and also increasing it. Can you please clarify this doubt of mine.

[@PolymerWorld]

If the chain side chain contains big bulky group like phenyl group, side groups or branching restricts the chain movement which leads to higher Tg. If the side group is small like methyl or ethyl side group, chain can easily move compared to bulky side group. In this case Tg will be low. I hope it helps.

[@estheradewole189]

Very explanatory thanks

[@PolymerWorld]

Thanks for the feedback.

[@SatyamKumar-yn2go]

Your voice is really nice!

[@PolymerWorld]

Thank you :)

[@NANI-16H.R.A]

Nice job thank you

[@gaojianz]

Great presentation Thank you very much.

[@PolymerWorld]

Glad you liked it!

[@gowthamv3687]

Topic on liquid crystal polymer

[@Shahzanan37]

Please answer me ,the elastomer at room temperature below or above tg ?

[@PolymerWorld]

Most elastomers show very low Tg. At room temperature elastomers are above Tg.

[@Shahzanan37]

@@PolymerWorld you mean it have low tg at room temperature

[@PolymerWorld]

Tg is a temperature at which polymeric materials goes from glassy state to rubbery state. For elastomers, the tg values are typically below 0 degree Celsius so at room temperature which is around 25 degree Celsius, it is above the Tg; therefore it shows high elongation at room temperature.

[@Shahzanan37]

@@PolymerWorld Ok thanks 🙏🙏❤❤

[@ahnafkhan2828]

good

[@PolymerWorld]

Thanks for the feedback.

[@sushmitagupta3444]

Only 8 videos hai ? Mam

[@PolymerWorld]

More videos are coming...let us know if you are interested in any specific topic. Thanks for watching!

[@jaipee123]

@@PolymerWorld mam would you please make a series of statistical thermodynamics lecturers.

[@materialsworld4gate]

For Material Science XE Group study materials, Question Paper solutions and preparation tips 👇👇👇👇👇 kzbin.info/www/bejne/p3qyfGaphs9rftU

[@rkmchemistry682]

Nice video #RKMChemistry

[@PolymerWorld]

Thank you!

[@hamzakhan9045]

Thanks 😊 ♥️

[@purnalingamr6803]

what happens when thermo-setting polymers are heated above the glass transition temperature ?

[@PolymerWorld]

Thermosetting polymers undergo curing on heating above glass transition temperature.

[@purnalingamr6803]

@@PolymerWorld Than you for the reply, but what i meant was post curing, lets heat the thermosetting polymer from room temperature to above its Tg, does it become rubbery( viscoelastic)? I had this question because, I read curing is irreversible for thermosetting polymers.

[@PolymerWorld]

Sorry for late reply somehow didn't see your reply. Yes you read correct curing is a irreversible process. Thermosetting polymers do not show viscoelasticity therefore when heated above Tg they do not become rubbery instead starts to cure and become hard. On further heating instead of getting soft these polymers starts to degrade.

[@purnalingamr6803]

@@PolymerWorld Thank you for the reply. I have a further question, let's say a thermosetting polymer (e.g, Epoxy) is fully cured at say 120 °C (Tg) and cooled down to room temperature. The operation temperature exceeds 120 °C. what will happen?

[@PolymerWorld]

If the operation temperature is within curing temp. + 50 degree C, post curing process will happen. If the operation temp. is higher than post curing temperature, polymer starts to degrade. Also if the polymer is kept at curing or post curing temperature for prolong period of time, polymer will start to show sign of degradation.

[@mardhiahms3522]

Can i ask a question.. why polystrene have a higher value of Tg than poly methyl acrylate?

[@PolymerWorld]

Polystyrene contains bulky side groups (phenyl ring) compared to acetate group in PMA which increases chain rigidity and therefore posses higher Tg than PMA.

[@tomufcg]

Thanks for the video, you could me tell, the Tg of a amorphous PS, for example, will vary with the cooling rate? The higher the cooling rate, does Tg move to higher temperatures?

[@PolymerWorld]

Yes. Considering the viscoelastic nature of polymeric material, deformation of a polymer chain is time dependent so any factor which can influence the time e.g., heating or cooling rate will influence the Tg of polymer.

[@tomufcg]

@@PolymerWorld thank you very much!

[@bina5580]

Thank you so much maam

[@PolymerWorld]

Thanks for watching!

[@rajeshwarialur6466]

Mam.can u send the notes about this topic

[@thanusubramoniam1367]

Whats the reason for Tg (measured value) variation (~4%) in the same sample (epoxy material). Tg performed in same sample in a gap of app 30 days.

[@PolymerWorld]

Variation in Tg of same epoxy sample after 30 days could be due to cross-linking over the time or moisture absorption. Also check reproducibility of the sample.

[@yarkapwelly7034]

Ma’am,Can you like please tell me why glass transition temperature of polyvinyl alcohol is greater than polyethylene?

[@PolymerWorld]

Bulky side group and presence of polar interaction (-OH bond is polar and can lead to inter molecular hydrogen bond) are responsible for higher glass transition temperature of polyvinyl alcohol.

[@yasirmujahid3233]

what if I am getting an upward shift in heat flux using DSC, rather than downward shift? Will it still be called glass transition temperature (range)? Thank you.

[@PolymerWorld]

Tg is an endothermic process (downward shift in heat flux). In DSC, exothermic transitions occur due to crystallization (during cooling), cold crystallization (during heating), cross-linking and oxidation reactions.

[@yasirmujahid3233]

@@PolymerWorld Thank you for your response. I am doing some research work on VBO process using carbon fibre prepregs. I conducted DSC to determine Tg value of the impregnated resin. My plot shows a small upward shoulder just before exothermic peak. I could not find any downward shift in the data. So is it possible for me to get Tg value at the small upward shift just before exothermic peak? if possible, could you please share your official email address? I would like to show you my plots and your help in this regard would be very much appreciated. thank you so much again.

[@PolymerWorld]

Share your email address. We will be happy to help.

[@yasirmujahid3233]

@@PolymerWorld [e-mail]

[@BC-yr6eg]

👍👍👍👍👍👍👍👍👍👍👍👍👍👍

[@dr.azharscienceandtech.9352]

Can you send me this book please?

[@PolymerWorld]

The video content is not from any particular book.

[@dr.azharscienceandtech.9352]

Thanks for such a great video....love from pakistan Azad kashmir

[@Dr.A.K6909]

mam please tells your name.

[@PolymerWorld]

My name is Anju Gupta.

[@shantogub]

hui