crazing in polymers (rus. крейзинг полимеров) — formation of ordered fibrillar-porous structures during orientation stretching of amorphous polymers in adsorption-active liquid media.


Crazing in polymers is a relatively new effective high-tech approach to creating nanocomposite polymeric materials and to introducing various special additives into polymer films and fibres. This technology is based on creating a porous nanostructure in the volume of the polymer, into which various additives can be introduced under certain conditions of deformation (stress level, nature of the medium in which the deformation occurs, temperature, stretching speed, etc. ); such additives give new useful features to the fibre or film, such as incombustibility, bactericidal activity, etc.

When the polymer is stretched in an adsorption-active liquid media, in contrast to stretching in the air, a system of nanopores emerges and develops spontaneously; such a system permeates the entire volume of the deformed polymer and the pores are continuously filled by the surrounding liquid. At the first stage of polymer stretching (up to the yield point) a number of crazes (Fig.) emerge on its surface; the crazes grow in the direction perpendicular to the axis of stretching, while maintaining almost constant width (hundreds of nanometres). This process continues until the growing crazes cross the cross-section of the sample; it is followed by broadening of the crazes in the direction of the axis of stretching with conversion of the polymer into a highly ordered fibrillised state. When a significant portion of the polymer is transferred into the oriented highly dispersed state, the formed porous structure collapses with a marked decrease in the cross-section of the deformed polymer, in porosity, average pore size and specific surface area. During the collapse a part of the liquid filling the nanopores is mechanically captured. If this liquid is a solution of a modifier in an adsorption-active medium, then the collapse of the structure is accompanied by a release of the liquid into the surrounding space and the mechanical capture of the dissolved modifier in the form of nano-sized inclusions.

Another promising application of crazing technology is the formation of micro- and nano-relief on the surface of polymer films and fibres in a continuous mode to improve their optical characteristics.


а — Schematic representation of individual stages of crazing in polymers: I — craze initiation; I

а — Schematic representation of individual stages of crazing in polymers: I — craze initiation; II — craze growth; III — expansion of crazes. 

b — Electron microphotograph of a polyethylene terephtalate sample deformed in n-propanol (×1000) [1].


  • Goldt Ilya V.
  • Nazarov Victor G.


  1. Volynskijj A.L. Rehbinder effect in polymers (in Russian) // Priroda. 2006. No 11. — (reference date: 12.12.2011).
  2. Volynskijj A.L., Bakeev N.F. Self-organized Structure of non-crystalline polymers (in Russian). — Moscow.: Fizmatlit, 2005. 232 pp.

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