# Can I change glass transition temperature (Tg) and impact resistance with additives?

I have three different HDPE polymers with different melting index but they don't have any elasticity. Physical form of polymers is granules. Can I change glass transition temperature (Tg) and impact resistance with additives?

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• No. Buy a suitable Polyethylene. – Karl Aug 23 '16 at 15:59

## 1 Answer

The glass transition temperature depends on the cooling rate and molecular weight distribution and could be influenced by additives:

Most liquid plasticizers are low molecular weight organic materials with a glass transition temperature in the range of $125-225^0\text{C}$. When this kind of additives is added to an organic polymer, the result is a weight averaging of the glass transition temperature between that of the polymer and that of the plasticiser if they are miscible. The reduction of the the glass transition temperature of a polymer by the plasticiser is usually about $5^0\text{C}$ per weight percent of plasticiser.

Impact modifiers ( a kind of additives) can affect the impact resistance of a polymer. Impact modifiers are key additives for increasing flexibility and impact strength to meet physical property requirements of rigid polymers. All impact modifiers are elastomeric or rubbery in nature, with a lower modulus than the host polymer. The dispersed rubber phase acts to absorb or dissipate the energy of impact in order to stop craze or crack propagation.

• Plasticisers don't work in PE, because they do not dissolve. You could try blending with some low Mw LDPE. – Karl Aug 23 '16 at 16:03