Hydroquinone is added to methyl methacrylate monomer
**Core Concept**
Hydroquinone is a common inhibitor used in the polymerization of methyl methacrylate monomer, a key component in acrylic resins and dental materials. This inhibition prevents premature polymerization and ensures the monomer remains liquid until the desired setting time.
**Why the Correct Answer is Right**
Hydroquinone acts as an antioxidant and inhibitor by disrupting the free radical chain reaction involved in the polymerization process. It reacts with the free radicals formed during polymerization, thereby preventing the propagation reaction and maintaining the monomer in a liquid state. This property is crucial in the production of dental materials, such as acrylic resins, where controlled polymerization is essential for optimal mechanical properties and durability.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the role of hydroquinone in the polymerization of methyl methacrylate monomer. While other inhibitors may be used, hydroquinone is a common and effective choice.
**Option B:** This option is incorrect because it suggests an unrelated function of hydroquinone, such as acting as a catalyst or initiator. Hydroquinone's role is to inhibit polymerization, not facilitate it.
**Option C:** This option is incorrect because it implies a different mechanism of action for hydroquinone, such as reacting with the monomer itself rather than the free radicals formed during polymerization.
**Clinical Pearl / High-Yield Fact**
It's essential to note that hydroquinone is added to methyl methacrylate monomer in a specific concentration to achieve optimal inhibition. An excessive amount of hydroquinone can lead to incomplete polymerization or affect the mechanical properties of the final product.
**Correct Answer:** B. Hydroquinone acts as an antioxidant and inhibitor by disrupting the free radical chain reaction involved in the polymerization process.