Silicone

 
What are the benefits of using silicone molds?

Hot and cold uses. The versatility of silicone molds allows you to use them for both cold meals (like sweet jelly, wipes, aspic, meat jelly, as well as ice) and for baking gastronomic delights (like quiches, flans, etc.).

Faster. The baking process in shallow molds is much faster, saving you time and energy.

Non stick. And their greatest advantage is that food does not stick to them, making un-molding virtually effortless.

Less fat. You can use less fat in your recipes, due to its non-stick properties, and you only need to grease a mold the first time you use it for baking.

Sweeter. You can make things sweeter, as the use of added sugar will not cause your baked goods to stick.

Easy clean. Molds easily wipe-clean, saving you time and detergents.

Durable. Silicone molds are durable, able to withstand more than 3000 uses in the oven.

Heat resistant. Heat-resistance is to 525°F (260°C).

Food approved. Soft silicone molds are permissible in commercial and industrial food applications.

Oven safe. Silicone molds can be used in both conventional and microwave ovens.

Freezer safe. Freeze food and beverages in the molds.

Shock proof. They can go from the freezer right into the oven, and vice versa.

 
Use and Care:

Before the first time you use a silicone mold:
     - Wash the mold in soapy water or in the dishwasher
     - Grease the inside of the mold with a little oil or melted butter. (No need to grease the mold after its first use.)

Oven rack or tray:
     - Larger molds should be placed right on the oven racks (not on a tray or cookie sheet) to allow better circulation of heat around the mold.
     - Small molds may be placed on a baking sheet (tray or cookie sheet) for stability.

Safe utensils:
     - Wooden, plastic or Teflon-coated tools without sharp surfaces.

Baking time:
     - Cooking temperatures are exactly the same as those used for traditional metal molds.
     - Shallower molds will bake faster than larger molds, so check frequently for doneness on first use.

Heat distribution:
     - Shallow molds, the most commonly available, work best, as silicone does not distribute heat evenly.
     - In a convection oven, place on a rack at mid-height in the oven
     - In a traditional oven, place molds on the lowest rack.
     - Keep the oven temperature below 525°F.
     - Foods that are baked in these molds usually come out with shiny surfaces.

Clean-up:
     - Rinse molds with warm water and a soft sponge between batches and after use.
     - If needed, sponge clean with some liquid detergent, then rinse thoroughly.
     - After washing and before refilling with another batch, allow the bakeware to dry in the oven at 325°F (150°C) for 2-3 minutes.

Never:
     - Never put an empty mold into the oven; if there's not enough pastry to fill the last few cavities, pour a little flour into the empty cavities it order to protect them.
     - Never use silicone molds under the broiler.
     - Never use sharp tools when turning over or removing baked items in the molds.
     - Never cut in the molds.
     - Never use metal brushes or abrasives to clean your molds.

 
What is silicone?

Simply put, Polysiloxane, (the proper name for Silicones), are stable synthetic compounds (polymers), with lubricating properties that mimic organic, carbon based compounds, such as petroleum, animal fats and vegetable oil.

Silicone is a term much like "plastic" - it covers a rather wide range of materials and properties. The chemistry of a particular polymer determines its characteristics, from hard and brittle varnishes, to soft and flexible rubbers. The initial work on polysiloxane chemistry dates back almost 60 years and it continues today.

Silicones are used for a lot of things. They can be elastomers and lubricating oils. The caulking in your bathroom is probably made of a silicone. Among other things, silicones are also used to make the heat resistant tiles on the bottom of the space shuttle, breast and other implants, and hair conditioners that don't cause buildup.

Dictionary.com defines Silicone as:

" 1) Any of a group of semi-inorganic polymers based on the structural unit R2SiO, where R is an organic group, characterized by wide-range thermal stability, high lubricity, extreme water repellence, and physiological inertness and used in adhesives, lubricants, protective coatings, paints, electrical insulation, synthetic rubber, and prosthetic replacements for body parts."

" 2) Any of a large class of siloxanes that are unusually stable over a wide range of temperatures; used in lubricants and adhesives and coatings and synthetic rubber and electrical insulation [syn: silicone polymer]"

Silicone is different from Silicon and Silica, though it contains a relatively high proportion of silicon. Silicon, which is found in rocks and sand, is the second most common element in the crust of our earth. It is not found in its elemental form, but occurs mainly as oxides and silicates. Silica is a three dimensional network of silicon dioxide, most commonly encountered as sand. Silica exists in crystalline and amorphous forms, is chemically resistant at ordinary temperatures, and can undergo a variety of transformations at high temperatures (greater than 500ºC, 950ºF) and pressures.

The basic difference between silicone polymers and "organic" polymers is in the molecular make-up. Silicone or Dimethyl Polysiloxane, is made up of silicone/oxygen linkages, the same found in high temperature materials such as quartz, glass, and sand. Natural rubber, or organic polymers, are made up of carbon/carbon linkages.

Through altering the chemical make-up of the silicones by adding phenyls, vinyls, and flourines, significant variations in physical properties can be achieved. Thus, molds from different manufacturers can vary in their quality and subsequent results.

Silicone is generally attacked by most concentrated solvents, oils, concentrated acids and diluted sodium hydroxide. It is a material of high chemical inertness, resistant to environmental impact (oxygen, ozone, water and light) and various liquid detergents, usable both in high (260°C, 525°F) and low (-70°C, -185°F) temperature.

Silicone is regulated for use with food under US Food & Drug Administration Title 21 Part 177 Section 2600 (Cite: 21CFR177.2600).

Patents:
Lekue, using Platinum as a  catalyst: #6,197,359 (Mar 06, 2001)
Others, using Peroxide as a catalyst: #7,105,193 (Sep 12, 2006)