Register to reply

How blue-tack sticks?

by sniffer
Tags: bluetack, sticks
Share this thread:
Jul24-05, 07:52 PM
P: 112
suppose we have a very smooth and hard surface such as mirror, and we stick a blue tack on it.

there is no chemical reaction. what force keeps it stuck?

is it electromagnetic?
Phys.Org News Partner Physics news on
Physical constant is constant even in strong gravitational fields
Physicists provide new insights into the world of quantum materials
Nuclear spins control current in plastic LED: Step toward quantum computing, spintronic memory, better displays
Jul24-05, 07:58 PM
Sci Advisor
PF Gold
brewnog's Avatar
P: 2,793
It's not electromagnetic as such, although there are certainly electromagnetic forces which play a part in the bonding within the substance.

It's just sticky! Long-chain hydrocarbon polymers often form these gooey, sticky substances. Turning them into a usable product is just a case of getting the right balance of tackiness, without being too sticky.
Jul24-05, 10:00 PM
DaveC426913's Avatar
P: 15,319
A good reference Brewnog, but for my money "becasue it's sticky" isn't really an answer. What does it mean for something to be sticky?

I found the answer (or at least, the author's belief) in your link:

"...Hydrocarbon polymers is the adhesive component in Blu-Tack. Polymers tend
to be pretty sticky; they are long chained hydrocarbons that have lots of
hydrogen on the surface that tend to form physical bonds with anything
that they come in contact with

Oct23-11, 07:50 AM
P: 4
How blue-tack sticks?

Hi there,
I'm also very interested in the mechanism of blu-tack.
I don't really understand why hydrocarbon polymers are adhesive. From my chemistry knowledge, hydrocarbon polymers are supposed to be non-polar, leave alone forming hydrogen bonds. Their nature should be like oil - slippery instead of sticky.
However, let's assume it is a long carbon chain with a lot of OH groups attached. How do you explain then, that blu-tack also sticks to smooth non-polar substances? No hydrogen bonds are supposed to be formed. I am still very confused.
Moreover, blu-tack has the property of being elastic, yet capable of being molded. Is its molecular structure like that of metal, which recoils by electrostatic force, or is it like a rubber band, which recoils due to thermo-energy?

In most elastic materials, such as metals used in springs, the elastic behavior is caused by bond distortions. When force is applied, bond lengths deviate from the (minimum energy) equilibrium and strain energy is stored electrostatically. Rubber is often assumed to behave in the same way, but it turns out this is a poor description. Rubber is a curious material because, unlike metals, strain energy is stored thermally.
Oct23-11, 07:58 AM
P: 5,632
I agree there is probably more to this than what's been discussed so far:

See here for some of the effects of hyrdogen's amazing:

Hydrogen bonding phenomena

Register to reply

Related Discussions
Glow sticks Chemistry 13
Blue Sky General Physics 4
Mission Mozzarella Sticks Succeeds! General Discussion 26
Water sticks. Classical Physics 3
Walking, You Sticks! Introductory Physics Homework 1