The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Reaction of Polyglycol ether with PVC pipe

I stored a stain removing chemical being used in Textile in a fibre tank. The nature of the chemical is nonionic based on Polyglycol ether solvent. The tank has a connecting pipe to another tank of the same material. The connecting pipe between the two tanks is of PVC. My problem here is that the chemical has caused a severe effect on PVC, and the strength of the PVC pipe has completely lost which seems that someone chemical reaction has been occurred. What might be the possible reaction behind? Any response will remarkably be appreciated.

Ijaz Hussain
- Faisalabad, Punjab, Pakistan
2003

At this point, you do not need anyone to tell you that PVC is not compatible with many organic chemicals. Even if you switch to a fiberglass pipe, you will need to check the chemical compatibility of that particular resin used for your chemical. Obviously whatever was used in the tank would work, if it was of similar construction. Veil layers and type of gel coat are also significant. Can you take the easy way out and use stainless?

James Watts
- Navarre, Florida
2003

Thanks for response. My question is still there. What is the chemical reaction behind interaction of PVC and Polyglycol ether?

Ijaz Hussain
- Pakistan
2003

---

First of two simultaneous responses --

Hi Ijaz,

What James Watt said is l00% correct. Yes, I agree. Let's go to a s.s. pipe between the two tanks UNLESS you are getting tank failure and then use mild steel or stainless of even, I guess, aluminum.

Why does this occur? Easy! PVC is attacked by all polar solvents and aromatics. What happens is that it will soften and lose strength. You might get away with Polypropylene but with ABS you'd run into worse problems!

PVC is superlative in strong acids and alkalies but not with most solvents.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2003

---

Second of two simultaneous responses --

I am sorry that I can not answer that question. I can not even make an educated guess. Asking a major manufacturer of PVC might be able to help you, but I would not bet on it. I also think that you will have to tell them why you need that specific knowledge. Their first thought is are you going to take this information to court. Most have zero desire to help any individual sue any company in their industry. It is quite simply easier to ignore you than to get into the middle of a fight.

James Watts
- Navarre, Florida
2003

---

Thanks James. The main purpose behind my question was only to get knowledge and the cause of the happening. I don't have any even thinking to go for court against the manufacturer. I always rush for the knowledge and always expect good people like you will guide me in any case. I am at present searching to get knowledge about the PVC in detail. Have you any source to get it? Please share it with me.

Again thanks.

Ijaz Hussain
- Faisalabad
2003

Can not help you on that. I was primarily an inorganic chemist. While I did design and install several systems, my concern was always what not to do and what was the optimum material to use with a cost benefit ratio for selection of materials.

James Watts
- Navarre, Florida
2003

Dear; as per your question according to my knowledge.that all stain removing products contains polar solvents for polar solvents pvc is poor conductor. you can replace it with PET or coat it with Teflon. this will solve your problem.

Talat Mahmood
- Pakistan
2003

---

PVC does not react chemically with polyglycol ether solvents. However because it is thermodynamically compatible with these polar solvents (in other words PVC is soluble in these solvents) it should never be used with these solvents. You will be better off using metal (the best) or neutral plastics such as high density PE type tubings for this application.

Navroz Boghani
- Budd Lake, New Jersey
2007

---

2007

Dear Ijaz,
I am late to read your query, any how. The problem occurs actually due to reaction of liquid with PVC. As the fiberglass tanks have no intimation of failure or fatigue etc., but if you just use fiberglass coating around the PVC pipe, the reaction will be minimized. But will not stop. You have to choose the appropriate material for the relevant liquids.
Regards

Adnan Riaz
- Karachi, Pakistan