×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Plastic Cleaning with Acid

Plastic Cleaning with Acid

Plastic Cleaning with Acid

(OP)
Can I clean plastic materials with nitric or sulfuric acid?

RE: Plastic Cleaning with Acid

A general answer is NO.

This is qualified by asking what is the plastic and what are the strengths and temperature of the acids. Both acids are highly hazardous to handle and can violently react with some plastics.

Comeback with details of what you are specifically trying to do.

RE: Plastic Cleaning with Acid

(OP)
I need to clean polyurethane and PMMA, to make mirror surface on them by silver coating. The surface has to be very clean for the chemical coating procedure.
One of the steps is cleaning the surface with nitric acid.
A slight change in machanical properties due to the acid-plastic material interaction may be acceptable, as far as the materal is cleaned thoughly. Can I use nitric acid to clean the plastic materials? What are the plastic materials that I cannot clean with the acid? Are there any alternatives? Thanks.

 Peter

  Peter

RE: Plastic Cleaning with Acid

kkim123,
You need to find some very detailed, Plating On Plastic (POP) instructions for your particular substrates.

The plastic is first alkaline cleaned & rinsed.

Conditioning: Some plastics are then slightly softened with chlorinated organics to make more susceptible to the acid.  

Etching:  The acid (often, hot chromic+sulfuric) attacks the plastic surface, breaking molecular bonds, converting it into a microscopically porous, wettable surface.

Neutralizing (sensitizing): A rinse containing complexing or reducing agents (for oxidizing acids such as chromic & nitric) follows.

Catalyzing (sensitizing):  A stannous chloride or dilute palladium chloride solution is used to catalyze (ativate) the surface for metal deposition.

Acceleration: Sometimes, a step using fluorides is used.

Silver can then be deposited using the Brashear Formula solution.

Caution: The procedure above follows ASTM B727, 'Standard Practice for Preparation of Plastics Materials for Electroplating,' which doesn't mention PMMA or PU.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close