Early plastics — notable contributors and materials Select the correct statement(s) regarding pioneers of plastics and their products.

Introduction / Context:
Materials science history illuminates why certain polymers dominate construction fittings, electrical parts, and finishes. Recognizing key inventors and the nature of their plastics strengthens understanding of thermosets and early thermoplastics relevant to building components.

Given Data / Assumptions:

• Parkes worked with nitrocellulose-based plastics; trade names are variably rendered historically.
• Baekeland created phenol–formaldehyde resin (Bakelite), a classic thermoset.
• Urea–formaldehyde resins were developed and commercialized in central Europe (e.g., by Pollak/IG Farben) for mouldings and laminates.

Concept / Approach:
Parkes’s nitrocellulose plastic anticipated celluloid and demonstrated the role of plasticizers. Baekeland’s Bakelite established thermoset moulding compounds for electrics, handles, and laminates. Urea–formaldehyde offered light-colored, fast-curing mouldings and adhesives in wood products, including construction-grade plywood resins.

Step-by-Step Solution:
Identify Parkes as an early pioneer with nitrocellulose-based plastic (Parkesine).Recognize Baekeland’s Bakelite as a seminal thermoset.Acknowledge urea–formaldehyde development by Austrian/central European chemists (Pollak et al.) leading to commercial plastics.Since each statement reflects a true contribution, select the comprehensive option.

Verification / Alternative check:
Museum archives and polymer histories corroborate these developments and their widespread applications in early 20th-century products.

Why Other Options Are Wrong:
Choosing any single statement ignores the broader historical picture in which all listed contributions are valid.

Common Pitfalls:
Confusing spelling variants (e.g., Parkesine) and conflating nitrocellulose with later celluloid; overlooking that urea–formaldehyde is a thermoset distinct from Bakelite in chemistry and properties.

Final Answer:
All of the above.