Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

PVC contaminated with POM "DANGEROUS" !!!

Status
Not open for further replies.

R.H

Materials
Dec 7, 2016
7

I just came to know that if PVC is contaminated with POM even in traces under the processing temperature. it could be a fatal threat. can anybody explain more.
 
Replies continue below

Recommended for you

It's well known in the industry that they mutually rapidly decompose. Most processors of POM do not allow PVC on site and vice versa. They need to be molten - mixing solid is okay.

www.tynevalleyplastics.co.uk

Politicians like to panic, they need activity. It is their substitute for achievement.
 
Thanks Pud,
Can you or anybody else please elaborate more like what reaction tacks place, and what are the consequences.

Thanks,
R.H
 
Incompatible Materials
Polyvinyl chloride compounds should not come into contact with acetal or acetal copolymers in elevated
temperature processing equipment. The two materials are not compatible and will react in a violent
decomposition when mixed under conditions of heat and pressure.

From:
 
POM (acetal) is prone to depolymerization, a chemical reaction whereby the polymer changes back to the starting material (monomer) which is a gas and rapid generation of gas can cause an explosion. The depolymerization reaction is catalyzed by acids and PVC generates such acid (HCl) when it's heated. So, the PVC can catalyze the explosive formation of gas from the POM. I have not checked this in detail but it's my guess as to what's happening.

Chris DeArmitt PhD FRSC
President

Plastic materials consultant to the Fortune 100
Creating New Materials - Problem Solving - Innovation Keynotes - Expert Witness
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor