TrueFalse 7 A networked polymer will have more ductility tha

True-False

7. A networked polymer will have more ductility than a branched polymer.

8. Molecular weight of a polymer chain cannot exceed 10,000 a.m.u.

9. Thermoset polymers are generally less ductile but stronger compared to thermoplastic polymers.

10. Thermoset polymers are generally considered to be more easily recycled compared to thermoplastic polymers.

11. Viscoelasticity of polymers is caused by the time dependent breaking and reforming of cross- links.

12. An elastomer has no glass transition temperature because it is 100% crystalline.

Solution

7. True

8. True

9. True..Thermoplast polymers contains long hydro carbon chains with primary bonding holding atoms together

10. False...Thermoset polymers are generally stronger than thermoplast polymers.. and thermoset polymers cannot be melted or reshaped

11. False..Viscoelasticity is due to the time dependent coiling and recoiling of polymer chains and does not involve the breaking or the reforming of cross-links.

12. False..All polymers have a glass transition temperature (Tg) because polymers can never be 100% crystalline. The Tg is well below room temperature for a material that is a good elastomer at room temperature. In addition, elastomers must be nearly 100% amorphous. Otherwise, they would have energy elasticity, not entropy elasticity.