How Is Color-Changing Plastic Made with DN BP?

TL;DR

Color-changing plastic is made by incorporating DN BP, a photochromic compound that changes from brownish yellow to blue under UV light or sunlight and slowly reverts in darkness. The compound is synthesized by nitrating two-benzyl pyridine, then isolated through neutralization and solvent extraction before being tested in plastic and photo-development experiments. Read on for the synthesis principles, color behavior, purification method, and planned applications.

Transcript

this video has been sponsored by Nord VPN you can go to Nord VPN comm / nyle read to get 77 percent off a three year plan today I'll be making a chemical called two to four die nitro benzyl pyridine or DN BP for short which exhibits something called photochromism this means that when it's exposed to light it undergoes a reversible change in color u... Read More

Key Insights

• 💱 DN BP is a photochromic compound that undergoes a reversible color change when exposed to UV or sunlight.
• ❓ The synthesis of DN BP can be achieved using a nitration reaction with sulfuric and nitric acid.
• 😎 DN BP is used in various products like sunglasses, toys, clothing, and cosmetics due to its ability to transition between different colors.
• 🪡 DN BP-coated paper can be used to develop photos, although the coating method needs refinement for optimal results.
• 💱 DN BP can be mixed with epoxy resin to create color-changing plastic, showcasing the photochromic properties of the compound.
• 🐢 The color-changing process of DN BP can be accelerated by heating or slowed down by keeping it in darkness.
• ❓ Different solvent and crystallization methods may influence the photochromic properties of DN BP.

Questions & Answers

Q: How is color-changing plastic made with DN BP?

The creator planned to use the synthesized DN BP to make a color-changing plastic. DN BP supplies the photochromic effect, changing from brownish yellow to blue when exposed to UV light or sunlight.

Q: What is DN BP?

DN BP is short for two to four dinitrobenzyl pyridine. It is a photochromic chemical, meaning that exposure to light causes a reversible color change.

Q: What color change does DN BP undergo?

Under normal conditions, DN BP is brownish yellow. It turns blue under UV light or sunlight and slowly returns to its original color after being left in the dark for several hours.

Q: How is DN BP synthesized from two-benzyl pyridine?

The synthesis uses sulfuric acid and nitric acid to nitrate two-benzyl pyridine. Their reaction forms nitronium ions, which act as the active nitrating species and add two nitro groups to produce DN BP as the major product.

Q: Why is the reaction mixture cooled before nitration?

The concentrated sulfuric acid is first cooled in an ice bath before two-benzyl pyridine and nitric acid are added. The nitric acid is introduced carefully and dropwise, after which the mixture is removed from the ice bath and heated.

Q: How is DN BP separated from the reaction mixture?

After heating, the reaction mixture is cooled, poured onto ice, and neutralized with sodium hydroxide until strongly basic. Diethyl ether is then added so the desired product dissolves in the upper ether layer while salts and many side products remain in the lower water layer.

Q: Why must the mixture stay cool during the ether extraction?

Diethyl ether has a very low boiling point and is extremely volatile. Keeping the mixture at or below room temperature prevents the ether from boiling away during extraction.

Q: What experiments were planned with the synthesized DN BP?

The creator wanted to develop a photo from a negative print and make color-changing plastic. The compound’s behavior under light and in darkness was also explored to test its photochromic properties.

Summary & Key Takeaways

• The video demonstrates the synthesis of a photochromic compound called DN BP, which undergoes a reversible color change when exposed to light.

• DN BP is used in various products like sunglasses, toys, clothing, and cosmetics due to its ability to transition between different colors.

• The video showcases experiments using DN BP to develop photos, create color-changing plastic, and explore its photochromic properties.