articles produced from hydrophobic polymers are surface - coated with thin films of starch in order to render the surfaces hydrophilic . the thin coatings form on the surfaces of plastic objects when the objects are placed in contact with hot , aqueous solutions of starch . these starch coatings are extremely adherent to the hydrophobic plastic surfaces under both wet and dry conditions , and they permit the surfaces to be uniformly wet with water . resultant products have improved biocompatibility , improved compatibility with hydrophilic reagents , reduced build - up of electrostatic charge , reduced blocking , reduced friction , improved absorption of water - based dyes , and improved adhesion properties . the starch coatings are non - toxic , inexpensive and biodegradable .