The polymer molecular is either thermodurcissable or thermoplastic, for example, plastique. What is the difference and how is the reactions enroll?

the polymer we can classify it accordingto it's heat behavior to two type

1- thermo plastic which we can re-formd or remold it via the heating due to it  contist of chains aren't linked togehther 

2- thhe second type of polymer according to this classification is thermosetting or  thermodurcissable this type of polymers we can not re-form it or re-mould it due to  it's structure which contain cross linking screen between polymer chains just we apply heating to re-form or remould we'll make degradation for carbon skeleton .

It is too easy to observe. Thermoplastic materials are those can be transformed several times, because  they don´t have any internal reaction to modify their structures.

However, Thermodurcissable materials can be transformed once. Their internal molecular structure produces reaction between several radicals and affect viscosity, and physical properties of material.

To go in details of structure, we talk about thermoplastic when the material consists on many chain of polymer which not linked with covalent bonds so when we heat it, the polymer chains slide over one other which make the material flow. Otherwise Thermodurcissable material is one consists on three-dimensionel structure which linked by covalent bonds so even when we heat it we can not make it flow.