Which of the following is not true for themoplastic polymers ?

Options

A. Thermoplastics are linear polymers .
B. They soften and melt on heating .
C. Molten polymer can be remoulded into any shape .
D. they cannot be remoulded into different shape

Explanation

To determine which statement is not true for thermoplastic polymers, we can analyze the characteristics of thermoplastic polymers step by step.

### Step 1: Understand the Definition of Thermoplastic Polymers
Thermoplastic polymers are a type of polymer that becomes pliable or moldable above a specific temperature and solidifies upon cooling. They are typically linear or branched structures.

**Hint:** Remember that thermoplastic polymers can change their physical state with temperature changes.

### Step 2: Analyze the Properties of Thermoplastic Polymers
1. **Linear or Branched Structure**: Thermoplastic polymers are generally linear or branched. This allows them to melt and flow when heated.

**Hint:** Think about the structure of the polymer and how it affects its melting behavior.

2. **Softening or Melting on Heating**: When thermoplastic polymers are heated, they soften and can be transformed into a viscous liquid. This property is crucial for processing and shaping these materials.

**Hint:** Consider the implications of heating on the physical state of the polymer.

3. **Remoldability**: Once melted, thermoplastic polymers can be remolded into different shapes. This is one of the key advantages of thermoplastics, as they can be reshaped multiple times without significant degradation.

**Hint:** Reflect on how the ability to remold affects the applications of thermoplastic materials.

### Step 3: Evaluate the Given Options
Now, let's evaluate the options provided in the question:

- **Option A**: Thermoplastics are linear polymers. (True)
- **Option B**: They soften or melt on heating. (True)
- **Option C**: Molten polymer can be remolded into any shape. (True)
- **Option D**: They cannot be remolded into different shapes. (False)

### Conclusion
From the analysis, we can see that Option D is the statement that is not true for thermoplastic polymers. Therefore, the answer to the question is that thermoplastic polymers **can** be remolded into different shapes.

**Final Answer:** Option D is not true for thermoplastic polymers.