Polymer surfaces are known to undergo degradation when then are exposed to weathering and UV radiation. To improve the surface protection of most commonly used polymers (e.g. polypropylene) against photodegradation and weathering, two methods are proposed: photochlorination by chlorine gas and photografting by epoxy acrylate coatings. Both methods produce crosslinking on the polymer surface which increases the stability and impact strength of the polymer chain. Stability induced by photografting can be detected by UV spectrophotometry after several hours of exposure of coated and uncoated polymer films to UV light. Polymers in the presence of chlorine gas can be transformed into conductive polymer chains upon irradiation, first by forming conjugated, chlorinated polymer sequences, then by extensive dehydrochlorination. Formation of polyene chains also increases the stability and impact strength to protect the surface. Stability of chlorinated film was also studied by determining the molecular weights of chlorinated and unchlorinated polymers after several hours of UV exposure.