The Tg (glass transition temperature) of PLA (Polylactic Acid) is typically around 60-65°C, which makes it a relatively brittle material at room temperature. However, there are a few things you can do to lower the Tg of PLA:
- Add plasticizers: Adding plasticizers, such as glycerol or citric acid, to PLA can help to lower the Tg and make the material more flexible. However, adding too much plasticizer can affect the mechanical properties of the PLA, so it is important to use the right amount.
- Blend with other polymers: Blending PLA with other polymers, such as VAE, ABS or PETG, can also help to lower the Tg and improve the flexibility of the material. However, blending can also affect other properties of the material, so it is important to consider the trade-offs. DPP-VAE is available up to -14°C Tg. DPP-VAE is water soluble and it can be partly biobased. Within a mixture with PLA, the end product can stillbe certified as compostable.
- Annealing: Annealing is a heat treatment process that can help to improve the mechanical properties of PLA, including lowering the Tg. By annealing the PLA at a specific temperature for a specific amount of time, the material can be made more flexible and less brittle.
- Increase molecular weight: Increasing the molecular weight of PLA can also help to lower the Tg and improve the flexibility of the material. This can be done by adjusting the polymerization process or using a higher molecular weight PLA resin.
Keep in mind that lowering the Tg of PLA can also affect other properties of the material, such as its strength and stiffness. It is important to consider the trade-offs and choose the best approach for your specific application.