silly string

By: Valentina CavalAnd

Wajeeha Jafferalli

SILLY STRING

THE HISTORY OF SILLY STRING

• Silly String was invented by Leonard A. Fish and Robert P. Cox

• A patent was issued in 1972 for foamable resinous composition

• Originally it was • named as :“squibbly.”

Composition• A resin forms the plastic structure of the strand. The original

formula used polyisobutyl methacrylate— an acrylic resin. • A surfactant—or surface-active agent—helps the resin foam

and modifies the stickiness of the strands. • Propellant: 75% liquid in the can : forces the other ingredients out of the aerosol can, and causes them to foam and helps form the skin. The propellant described in the patent is Freon-12. • The Silly String manufactured today uses

other propellants –Freon-12 is an ozone depleting substance that is no longer manufactured.

ELEMENTS IN SILLY STRING

Dibutyl phthalate makes it sticky to the touch.

Silicone fluids such as dimethyl siloxane make the finished streamers easier to peel away from most targets.

A bit of solvent such as dichloromethane keeps everything as a one-phase mixture.

dimethyl siloxane dichloromethaneDibutyl phthalate

Chemical Structures

How does it work?At normal air pressure the propellant in Silly String would be a gas. The high pressure inside the can

keeps it in its liquid state. When you press the nozzle,

a valve opens inside the can, giving the highly

compressed liquid a chance to escape. Liquid rapidly

moves up the tube inside the can, and travels from the

high-pressure environment inside to the lower-pressure

environment outside. Outside of the can, the

liquid propellant becomes a gas, causing the remaining

ingredients to foam.

Silly String Yesteryear:• It was used by American

and British forces to detect tripwires for explosive booby traps.

• The soldier would stand in the doorway and spray the material over the suspect area. If the string fell to the ground there were no tripwires. However, if there was a tripwire, the string would be suspended in the air without pulling the wire

• They can not use silly string in the current war because you cant ship aerosol over seas

Silly String Today:

• Family Games• Parties: surprise welcome home graduation weddings• Child activities

Is Silly String dangerous?

• Its large proportion of propellant can also give Silly String two seemingly opposite safety hazards:

• Some propellants are flammable, and others become so cold when leaving the container that they can freeze a person's skin.

Interesting Facts• Silly string can clog storm drains and

take up space in landfills.

• Silly String is banned in Hollywood on Halloween night : If you are

caught with silly string you could be faced with a $1,000 fine!

For your Entertainment:http://www.youtube.com/watch?v=UWIsnpsAfSs

Bibliographyhttp://www.youtube.com/watch?v=w8efguf0XOs&feature=related

http://entertainment.howstuffworks.com/silly-string1.htm

http://gizmodo.com/294660/silly-string-rifle-makes-war-games-sillier

http://commons.wikimedia.org/wiki/File:Mgm_Silly_string_roadsign.jpg

http://www.aviary.com/artists/mpeutz/creations/seriouslyjanes_silly_string

http://www.drinkstuff.com/products/product.asp?ID=978