A LEVEL CHEMISTRY molecular forces

No, it is correct.

The idea of a plasticiser is to weaken the intermolecular bonds between polymer chains. If they formed stronger bonds, then that would have the opposite effect.

Typically, the polymers will form strong intermolecular bonds that make the structure rigid. Plasticisers fit inbetween the polymer chains, forming weaker intermolecular bonds than the polymer-polymer interactions. Also, this makes the polymer chains become more seperated, weakening the intermolecular bonds between neighbouring chains. The weak plasticiser-polymer interactions combined with the weakening of the polymer-polymer interactions causes the structure to become more flexible.

Firstly, a plasticiser is something added to a polymer to make it more flexible. They are mainly used in Plastics to make them more mouldable at a lower temperature

For example, let's say we have a container made of PVC

As we can see, the red lines represent the polymer chains. There are strong intermolecular forces in between each chain which makes the plastic strong.

Now if we add a plasticiser:

The yellow dots represent the plasticiser molecules, as we can see, the PVC chains are now further apart resulting in weaker intermolecular forces and therefore a more flexible plastic. The polymer molecules can easily slide over eachother and the polymer structure is disrupted by the addition of a plasticiser. Without a plasticiser, the plastic would have to be heated in order to mould it into a shape, and with PVC, if we heat it too much or burn it, it can release Chlorine gas as well as other chemicals called Dioxins which we don't want!

I hope that helped and my 30 second drawings in paint helped lol