Distinguishing Between HD and LD Polyethylene
A glass column with clear liquid containing two black solids, each surrounded by bubbles. One floating solid is shaped like the letter L, and the sinking solid is shaped like the letter H.
Description: Samples of high density and low density polyethylene are placed in a 50/50 water/alcohol mixture. The low density polyethylene floats while the high density polyethylene sinks.
Source: Journal of Chemical Education – Vol. 63
Year: 1986 Vol: 63 Page: 417
Keywords: Density, Plastics, Polymers
Rating: 
Hazard: Medium
- Acute toxicity hazard – oral, dermal, inhalation
- Flammability hazard
- Specific organ toxicity – single exposure – eyes
Effectiveness: Average
- Results are observable without guidance
- Contrast between systems is noticeable
- Time to results is low
- Mild effects are seen by audience
- Excellent reliability
Difficulty: Low
- Demos do not involve deep attention
- Procedures are simple
- Simple manipulations for most to perform
Safety Precautions:
- Eye protection required
- Gloves required
- ABC fire extinguisher on hand
- Absorbent materials on hand
Class: Organic Chemistry, Polymers
Division: General
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