Yes, synthetic rubber is an elastomer. Elastomers are polymers that have the ability to return to their original shape after being stretched or deformed. Synthetic rubber is a type of elastomer that is produced through chemical processes to mimic the properties of natural rubber. It is used in a wide range of applications due to its elasticity and durability. **

Thermoplastics are formed in a reaction pathway that involves the polymer chains being able to be repeatedly softened and hardened through heating and cooling. Thermosets are formed in a reaction pathway that involves irreversible cross-linking of polymer chains, resulting in a rigid and durable material. Elastomers are formed in a reaction pathway that involves the polymer chains having the ability to return to their original shape after being stretched or deformed, providing elasticity and flexibility. **

Polyurethane as a thermoplastic is known for its ability to be melted and reformed multiple times without significant degradation in its properties. As a thermoset, polyurethane is characterized by its ability to undergo a chemical reaction during curing, resulting in a rigid and durable material that cannot be remelted. Lastly, as an elastomer, polyurethane exhibits excellent elasticity, flexibility, and resistance to abrasion, making it suitable for a wide range of applications such as seals, gaskets, and flexible parts. **

The formation of a thermoplastic is typically achieved through a polymerization reaction pathway, where monomers are linked together to form long chains that can be repeatedly melted and solidified. Thermosets are formed through a crosslinking reaction pathway, where the polymer chains are permanently linked together, creating a rigid and infusible structure. Elastomers are formed through a combination of crosslinking and polymerization, resulting in a material that can be stretched and returned to its original shape. **

The class of plastics that has the property of being shatterproof is thermoset. Thermoset plastics are rigid and hard, making them resistant to shattering upon impact. This property makes thermoset plastics suitable for applications where durability and impact resistance are important, such as in automotive parts or electronic components. **

The class of plastics that has the property of being shatterproof is thermosetting plastic. Thermosetting plastics are rigid and strong, and once they are formed into a specific shape, they cannot be reshaped or melted. This makes them resistant to shattering or breaking under impact, making them suitable for applications where durability is important, such as in electrical insulators, automotive parts, and kitchenware. **

UPS Express offers guaranteed next business day delivery by 10:30 a.m., 12:00 noon, or end of day, depending on the destination. This service is available for shipments within the U.S. and to more than 220 countries and territories worldwide. UPS Express is known for its fast and reliable delivery, making it a popular choice for urgent shipments. **

DHL Express is known for its fast and reliable delivery service. They offer a range of shipping options, including same-day, next-day, and express delivery, depending on the destination and service selected. DHL Express has a strong global network and efficient logistics system, allowing them to deliver packages quickly and efficiently to over 220 countries and territories worldwide. Overall, DHL Express is considered one of the fastest international shipping services available. **