Binder (material)

A binder is any material or substance that holds or draws other materials together to form a cohesive whole mechanically, chemically, or as an adhesive. Often materials labeled as binders in different proportions or uses can have their roles reversed with what they are binding. An example is straw helping to mechanically bind clay together as in the building material cob, and clay as an adhesive helping to bind straw together as in a natural insulation. In a more narrow sense, binders are substances that transition from dough-like to stonlike state and, thus, bind filler power/particles added into it. The transition/binding property is used widely to prepare shaped articles (e.g. pots and vases) or to bind solid pieces (e.g. bricks). Binders are loosely classified as organic (bitums, animal and plant glues, polymers) and inorganic (lime, cement, gypsum, liquid glass, etc.) Based on their chemical resistance, binders are classifies by the field of use: air (gypsum, air-cements, magnesia) , water (roman cement, portland cement) , acid-resistant (silicon fluoride cement, quartz cement), and autoclavable (harden at 170 to 300°С i.e. 8-16 atm pressure and, e.g, comprise CaSiO3 materials) . Examples of mechanical binders are bond stones in masonry and tie beams in timber framing.