Which thermosetting “amino” resin family results from condensation polymerization of formaldehyde with urea or with melamine and is widely used in laminates, molded ware, and coatings?

Chemical Engineering Polymer Technology Difficulty: Easy
Choose an option
  • A
    Epoxy resins
  • B
    Amino resins
  • C
    Alkyd resins
  • D
    Phenolic resins

Answer

Correct Answer: Amino resins

Explanation

Introduction / Context:Amino resins are important thermosets in surface finishes, laminates, and molding. Recognizing the condensation pairs (formaldehyde with urea or melamine) clarifies performance traits like hardness, clarity, and heat resistance compared to other resin families such as phenolics, epoxies, and alkyds.

Given Data / Assumptions:

  • Monomers: formaldehyde plus urea or melamine.
  • Applications: decorative laminates, dinnerware, coatings crosslinkers.
  • Network-forming condensation creating hard, thermoset structures.

Concept / Approach:

Urea–formaldehyde (UF) and melamine–formaldehyde (MF) are classic amino resins. They cure to hard, glossy, scratch-resistant networks. Epoxies are formed from epoxides and amines/anhydrides; phenolics from phenol and formaldehyde; alkyds from polyols and polyacids (often oil-modified). Thus the formaldehyde + urea/melamine route uniquely identifies amino resins.

Step-by-Step Solution:

Match monomer pair → formaldehyde with urea/melamine.Identify resin family → amino (UF/MF).Reject other resin classes with different monomer chemistries.

Verification / Alternative check:

Coatings and laminate industry references list UF/MF as amino resins, often used as crosslinkers with alkyds/acrylics for baking enamels.

Why Other Options Are Wrong:

Epoxy: No formaldehyde–urea/melamine condensation. Alkyd: Polyester networks from polyols and acids. Phenolic: Phenol–formaldehyde, not urea/melamine–formaldehyde.

Common Pitfalls:

Confusing phenolic with melamine formaldehyde due to “formaldehyde” in both; overlooking the amide/amine functionality in amino resins.

Final Answer:

Amino resins

Discussion & Comments
No comments yet. Be the first to comment!
Join Discussion