Influence of small amount dispersive additives on the weather ability of PVC‐films

Abstract

Three types o f transparent PVC-films before and a f t e r exposition i n the weather conditions are studied. The f i r s t f i l m ( t h e c o n t r o l ) i s p l a s t i c i z e d and s t a b i l i z e d ; the second i s s i m i l a r t o the f i r s t but 1 p a r t o f cuprous oxide ( C u a ) i s incorporated i n it, while i n the t h i r d 1 p a r t o f aluminium (A11 powder i s added. I t i s found t h a t the l i g h t transparency drcreasrr by 2-7% upon adding Cu=O and by 17-36% upon adding Al-powder. UV-visible measurements, colourimetric measurements and m i c r o u o p i c i n v e s t i g a t i o n s are used f o r examining PVCr a n p l r s properties during weathering. The surface layer chenical changrr are studied by means o f WIR-IR-spectroscopy. The t o t a l colour v a r i a t i o n ( A Ellb) i n the case o f 12 months aged WC-film, containing Cu=O, 5hons 11 r e l a t i v e u n i t s i n comparison w i t h 37 r e l a t i v e u n i t s f o r the other two materials. A r e t a r d i n g a c t i o n o f CuzO and an accelerated e f f e c t o f A1powder on the weather degradation o f c l e a r s o f t PVC-films are ertablished. The influence o f the chemical properties and d i f f r r m n t s i r e d i s t r i b u t i o n o f the dispersive a d d i t i v e s on p h o t w x i d a t i v e b e h a v i w r o f WC-compositions are discussed.