question about coating on polycarbonate

[Seawitch]

I've been writing an article on plastic, and I need some help.

Polycarbonate scratches very easily, but it's possible to buy it with a coating on it to prevent/limit scratching. It's also possible to buy a product and coat it yourself.

It's EXTREMELY difficult to get anyone to tell me exactly what the coating is made of, but I did get my hands on an MSDS for one product used to coat polycarbonate. See screenshot. Most plastic companies just say that it's a proprietary concoction.

My question is would this coating dissolve in saltwater if, for example, someone made a tank out of polycarbonate. My article sits in limbo until I can get an answer to this question.

 

[virtual reality]

Found this at E Plastics:

Chemical Tested Resistance Time
Acetone > 24 hrs
Unleaded Gasoline > 24 hrs
Hydrochloric Acid (10%) > 24 hrs
Isopropyl Alcohol (IPA) > 24 hrs
Methyl Alcohol > 24 hrs
Methylene Chloride > 24 hrs
Methyl Ethyl Ketone > 24 hrs
Nitric Acid (100%) >1 hr but < 24 hrs
Sodium Hydroxide (10%) >1 hr but < 24 hrs
Sulfuric Acid (1%) > 24 hrs
Toluene > 24 hrs

Contact them and ask.

 

[Seawitch]

Found this at E Plastics:

Chemical Tested Resistance Time
Acetone > 24 hrs
Unleaded Gasoline > 24 hrs
Hydrochloric Acid (10%) > 24 hrs
Isopropyl Alcohol (IPA) > 24 hrs
Methyl Alcohol > 24 hrs
Methylene Chloride > 24 hrs
Methyl Ethyl Ketone > 24 hrs
Nitric Acid (100%) >1 hr but < 24 hrs
Sodium Hydroxide (10%) >1 hr but < 24 hrs
Sulfuric Acid (1%) > 24 hrs
Toluene > 24 hrs

Contact them and ask.

Thank you. What is this resistance to?

 

[virtual reality]

Here check it out:

https://www.eplastics.com/polycarbo...onate sheet&utm_content=UV Abrasion Resistant

 

[Seawitch]

Here check it out:

https://www.eplastics.com/polycarbonate/sheets/abrasion-uv-resistant?msclkid=e412fb494eed14ef471ea7f1fa8f246e&utm_source=bing&utm_medium=cpc&utm_campaign=Polycarbonate&utm_term=scratch resistant polycarbonate sheet&utm_content=UV Abrasion Resistant

Okay, I see. Thank you. The question is would the coating dissolve in 80F saltwater. I've asked a dozen of these companies and no one can give me a straight answer.

 

[virtual reality]

Most coatings I seen said they were UV or radiation cured

 

[Seawitch]

Most coatings I seen said they were UV or radiation cured

Apparently there are several different types of coatings you can get: UV-resistant, and/or scratch-resistant are just two of the possibilities.

 

[virtual reality]

I just talked to the guy there, He said saltwater is not a problem at all.

 

[virtual reality]

Hope that helps

 

[Seawitch]

Wow, thanks @virtual reality. You got further in 15 minutes, then I did in 3 months!

 

[redfishbluefish]

Three of the coatings I'm aware of are Weetect, Safecoat 401 and Safecoat 404. Maybe search the MSDS on these guys. I know the Safecoat products are similar to a paint. Hope this helps.

 

[Daletracks]

I just came across your question as I was doing my own research for sailboat windshield and hatch covers. Almost all of the coatings seem to be polysiloxanes. You probably have your answer by now, but there may be others looking for more info.

Polysiloxane (or polymethylsiloxane) is a very heavily cross-linked silicone polymer. It is hydrophobic and seriously inert. It is used in medical implants and extremely caustic chemical tanks without problem. So, seeing it dissolve in seawater seems unthinkable, kind of like seawater dissolving glass.

Here are some links:

About Safecoat 400 series and Abrasil coatings:
https://www.optical-coatings.com/technical

About siloxanes in general:
https://www.sciencedirect.com/topics/medicine-and-dentistry/polysiloxane

Here is a book that looks to be a more-than-you-wanted reference. In case the link breaks, the title is Silica-based Materials for Advanced Chemical Applications by Mario Pagliaro. The section on scratch-resistant coatings is in 4.5. The link is to the page in Google Books:
https://books.google.com.pa/books?i...XoECAkQAQ#v=onepage&q=abrasil coating&f=false

I’m struggling with finding info on how the coatings are applied. Some products are sheets and some are liquid condensed on. Both are either baked on or UV activated, both of which trigger the final polymerization.

 

[Randy Holmes-Farley Verified Community Expert]

Okay, I see. Thank you. The question is would the coating dissolve in 80F saltwater. I've asked a dozen of these companies and no one can give me a straight answer.

Normal scratch resistant coatings on eye glasses do not wash off in fresh water, and seawater will be no more effective at washing them off. They are crosslinked polymers that do not dissolve.