Shybyryn O. The influence of molecular and supermolecular structure on the photochemical modification efficiency of polyolefines and blends on their basis

The interdependances of photoinitiated process in polyolefins with different molecular and supermolecular structures (PP,PB, copolymer ethylene/propylene, ultra high molecular weigth fiber) were investigated. It was shown that application of photocrosslinking method for polyolefins with branched structure and their blends has several advantages against related to the conventional methods. Relatively dense network of chemical links could be created in polymer matrix via photochemical modification. The principle possibility of physico-mechanical properties tailoring due to crosslinking of polymer materials was proved. First of all, this is allow to decrease sufficiently creep, to increase thermostability and adhision to hinders. This method improves also the interphase adhision in polyolefins blends and prevents coalescence of the microphase of components during long time exploitation at elavated temperatures (70 oC). This enables to expand the temperature interval of polyolefins blends application. Th e new method of heterogeneous modification of compatibilized blends proposed which includes selective crosslinking of compatibilises and interphase of components. Such modification doesn't cause any detereoration of blends ductility. Due to this modification crosslinked composites had the deformation properties higher than uncrosslinked after 7 months of high temperature endurance.