Slime! Polymer Crosslinking Explained in the Kitchen

[@yifengpeng5514]

please，keep update video. We really need this experimental demo. Great thanks to you. --Y.F. Peng From Dalian University of technology.

[@mevansthechemist]

Dr. Sydlik, your channel is awesome! Keep making videos! 😁 Greetings from Georgia Tech.

[@faizasaif7849]

Hello I have a question, if we use borax as crosslinking agent, it leaves or breaks the bond after sometime and it turns polyvinyl alcohol into water consistency. Please guide what to do about this?

[@tatembannister]

Thanks, Prof! I enjoyed watching!

[@FM-mx6ld]

Super amazing explanation! Thank you!

[@alphaworld6247]

Hallelujah, God Bless you Professor

[@gonzlocarrera9949]

Awesome! Thank you, I'm not a chemist but have been interested lately in bio polymers and have been searching for information about crosslinking. I tried to make a hydrophobic starch bioplastic using citric acid as a cross linking agent. Would you happen to know what else I could use, it seems the citric acid gives the starch a lot more strength but it isn't hydrophobic yet, just resists a lot more water.

[@StefanieSydlik]

Hi! You could try the boric acid (borax) that we use in this video! Feel free to ask again if that doesn't work. Sorry for my delay!

[@moustaphamohamedmahamoud6367]

Thank you very much, it really helps!

[@myratvelnazarov9862]

Hello, thank you for your amazing lesson! I have a question, Can you explain please a bit more about Molecular weight between cross links? thank you

[@StefanieSydlik]

Hi Myrat! Thanks for asking. Molecular weight (in linear polymers) is the length of the polymer molecule strand. In general with linear polymers, the material becomes stronger as we increase this length. In a crosslinked system (thermoset or hydrogel like we create here), we create the new bonds here between boron and oxygen. For these cross linked polymers, we introduce a new factor: the molecular weight between crosslinks. This is the length of polymer chain between each new B-O bond. As the molecular weight between crosslinks decreases (or, more B-O bonds are formed to bind polymer chains together) the crosslinked polymer becomes stiffer. I hope this helps!

[@myratvelnazarov9862]

@@StefanieSydlik Thank you very much, now I understand clearly, I really appreciate your help!

[@mrassiwala2000]

Means low vescocity after melt

[@mrassiwala2000]

I want some advice from u can u tell me any plastic which melt like water after hearing

[@sarahtakach1326]

Previous time Question What can we do to avoid formation of cross links between spaghetti 🍝???? i need an answer for this question please asap!!!xoxox

[@StefanieSydlik]

Hi! So in spaghetti, those are actually entanglements, since there is not a covalent bond between the spaghetti strands. To avoid this, you can make your spaghetti shorter (break it in two before putting it in the pan)-- this works in polymers too! We call it an entanglement molecular weight. You can also add some oil, to prevent the sticking-- in polymers, this is analogous to adding a plasticizer. Hope this helps!

[@nickfeijoo7779]

Thanks :) I’m a researcher working on hydrogens right now I’d love to email you