𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭 : 𝐃𝐈𝐍𝐏 𝐚𝐧𝐝 𝐃𝐎𝐓𝐏 𝐦𝐚𝐲 𝐥𝐨𝐨𝐤 𝐢𝐧𝐭𝐞𝐫𝐜𝐡𝐚𝐧𝐠𝐞𝐚𝐛𝐥𝐞 𝐨𝐧 𝐚 𝐏𝐕𝐂 𝐟𝐨𝐫𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐬𝐡𝐞𝐞𝐭.

𝐒𝐮𝐧𝐝𝐚𝐲'𝐬 𝐓𝐇𝐎𝐔𝐆𝐇𝐓𝐅𝐔𝐋 𝐏𝐨𝐬𝐭

𝐍𝐨𝐛𝐨𝐝𝐲 𝐭𝐞𝐥𝐥𝐬 𝐲𝐨𝐮 𝐭𝐡𝐢𝐬 𝐮𝐧𝐭𝐢𝐥 𝐭𝐡𝐞 𝐟𝐢𝐫𝐬𝐭 𝐰𝐢𝐧𝐭𝐞𝐫 𝐟𝐚𝐢𝐥𝐮𝐫𝐞:

𝐃𝐈𝐍𝐏 𝐚𝐧𝐝 𝐃𝐎𝐓𝐏 𝐦𝐚𝐲 𝐥𝐨𝐨𝐤 𝐢𝐧𝐭𝐞𝐫𝐜𝐡𝐚𝐧𝐠𝐞𝐚𝐛𝐥𝐞 𝐨𝐧 𝐚 𝐏𝐕𝐂 𝐟𝐨𝐫𝐦𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐬𝐡𝐞𝐞𝐭.

They are not automatically interchangeable at low temperature.

Same PVC resin.

Similar Shore A.

Similar phr.

Similar tensile and elongation at 23°C.

Then the product sees -20°C.

And suddenly the “drop-in replacement” needs a much closer look.

The mistake is simple:

Using room-temperature QC to predict cold-weather performance.

For flexible PVC, Shore A is useful.

But Shore A is not cold flexibility.

Elongation at 23°C is useful.

But it is not cold bend.

A plasticizer change can affect:

• fusion behavior

• plasticizer efficiency

• modulus at low temperature

• brittleness temperature

• volatility and mass loss

• aging performance

• migration and extraction behavior

• retention of flexibility after heat aging

DINP and DOTP can both be good plasticizers.

But a 1:1 swap should never be approved only because the compound looks similar at room temperature.

The real question is:

Does the compound still flex after aging, at the lowest service temperature, under real mechanical stress?

For cold-weather PVC, I would want to see:

• cold bend or cold mandrel

• brittle point or Clash-Berg

• heat-aged cold flexibility

• mass loss after aging

• migration or extraction test, where relevant

• fusion/processability verification

DOTP is not “bad.”

DINP is not “old.”

But they are different plasticizer chemistries.

And PVC does not care what the substitution spreadsheet says.

It only cares what happens in the field.

Have you ever seen a plasticizer swap pass QC but fail in winter?

source : Orbimind AB

#PVC #Plasticizers #DOTP #DINP #FlexiblePVC

#PolymerEngineering #Compounding #PVCFormulation