Rubber Accelerator D (DPG) in Vulcanization
Rubber accelerator D (DPG, CAS 102-06-7) is a guanidine accelerator used mainly as a secondary accelerator and activator. This page explains what it does in the vulcanization system, where it is used, and how it is combined with thiazoles and sulfenamides.
What DPG does in the cure system
| Role | What happens |
|---|---|
| Secondary accelerator | Raises the cure rate of a thiazole or sulfenamide system |
| Activator | Increases the activity of the primary accelerator |
| Modulus builder | Raises crosslink density and modulus |
DPG is very active per unit weight, so it is used at low levels. It works with the zinc oxide/stearic acid activator system and elemental sulfur.
Where DPG is used
| Application | Role of DPG |
|---|---|
| Thiazole systems (MBT/MBTS) | Classic fast general-purpose cure |
| Sulfenamide systems (CZ/TBBS) | Boosts cure rate while keeping delay |
| Latex compounds | Accelerator for dipping and foam |
| Hard rubber / ebonite | High-modulus compounds |
Combining DPG with a primary accelerator
| Combination | Character |
|---|---|
| MBTS + DPG | Fast, economical general-purpose cure |
| MBT + DPG | Fast cure; watch scorch |
| CZ/TBBS + small DPG | Raises cure rate; keep PVI or a retarder in reserve |
DPG is often the last adjustment to a cure system: the primary accelerator sets the character, and a small amount of DPG fine-tunes the rate and modulus.
Scorch: the trade-off
- DPG is very active – over-use causes scorch and reduces the processing window.
- Keep the level low – a little goes a long way.
- Use a retarder if needed – PVI can restore the processing window if more speed is wanted.
- Confirm on the rheometer – set the level so scorch time and cure rate are both acceptable.
Frequently Asked Questions
Is DPG a primary or secondary accelerator?
It can act as a primary accelerator, but is most often used as a secondary accelerator / booster with thiazoles and sulfenamides.
What does DPG do to modulus?
It raises crosslink density, so it increases modulus – useful for high-modulus compounds.
Can DPG cause scorch?
Yes – because it is very active, over-use can cause scorch; its level is kept low.
Is DPG used in latex?
Yes – it is a common accelerator for latex dipping and foam.
Is DPG a skin sensitiser?
It is an irritant and a potential skin sensitiser; avoid skin contact.
Related reading
- Rubber accelerator D (DPG, CAS 102-06-7): properties and applications
- Rubber antioxidants and accelerators: selection guide
- Accelerator MBTS (DM): properties and applications
- Accelerator D (DPG, CAS 102-06-7) – product page
PolyBlueChem supplies Rubber accelerator D (DPG, CAS 102-06-7) for rubber vulcanization, with per-batch COA and SDS. Contact us with your application and tonnage.