Naslov
Thermally Stimulated Oxidative Degradation of High Impact Polystyrene with Nitric Acid

Autori
Hace, Drago ; Kovačević, Vera ; Pajc-Liplin, Davorka

Izvornik
Polymer engineering and science (0032-3888) 36 (1996), 8; 1140-1151

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Chemical properties; high impact polystyrene; mechanical properties; morphological properties; nitric acid; oxidative degradation

Sažetak
The practical application of high impact polystyrene (HIPS) depends on the resistance to aging in aggressive environments. The investigation of morphological, mechanical, and chemical properties was made on HIPS samples of various thickness. The property deterioration of HIPS caused by concentrated nitric acid and heat was studied. The diffusion trought micropores formed visible cracks that finally led to the complete destruction into a powder. The rapid loss in mechanical properties was explained in terms of scission reaction of the graft polybutadiene (PB) with the homopolystyrene (PS) matrix. Comparative measurements of pure PS and PB under the same conditions were helpful in resolving parallel reactions that preferentially take place in PS and /or in PB sequences. It was established that higher degree of nitration caused by higher temperature results in increased insolubility owing to parallel crosslinking reactions. The nitric acid attack on HIPS caused scission reactions, which also led to the oxidative degradation, more pronounced in the PS phase in the soluble part of HIPS.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA