Gardi, S.; Giannone, L.; Sarti, G.; Sarti, G. Surface Chalking upon Weathering of Dark-Colored PVC Articles and Relevant Stabilizers. Polymers2024, 16, 1047.
Gardi, S.; Giannone, L.; Sarti, G.; Sarti, G. Surface Chalking upon Weathering of Dark-Colored PVC Articles and Relevant Stabilizers. Polymers 2024, 16, 1047.
Gardi, S.; Giannone, L.; Sarti, G.; Sarti, G. Surface Chalking upon Weathering of Dark-Colored PVC Articles and Relevant Stabilizers. Polymers2024, 16, 1047.
Gardi, S.; Giannone, L.; Sarti, G.; Sarti, G. Surface Chalking upon Weathering of Dark-Colored PVC Articles and Relevant Stabilizers. Polymers 2024, 16, 1047.
Abstract
PVC items are environmentally friendly as, unlike polyolefins, they are mainly based on chlorine, one of the most abundant elements on earth. However, in the eco-design context, articles' durability plays the crucial role, contributing to the enhancement of their sustainability. In this framework the research on additives capable of increasing the weatherability of outdoor articles is essential. The theory section of the paper reviews the mechanisms of weathering leading to PVC degradation that undermine the durability of items such as window frames or roller shutters. The weathering of PVC items is a complex phenomenon involving photo-chemical and secondary chemical reactions, that yields the formation of conjugated polyene sequences underskin in absence of oxygen and carbonyls in the surface. Here the chain scission of the polymer backbone occurs, bringing the disintegration of the surface of the item and causing the typical discoloration called chalking, especially evident in dark-colored articles. In the experimental section of the paper the effect of different acid scavengers on the item weathering has been studied with natural outdoor and two accelerated exposures, xenon-arc and Q-UV testing devices. Results confirm that some acid scavengers are efficient in preventing chalking, but some are ineffective or even detrimental. Thus, the PVC formulations of durable articles upon weathering still depend on a complex choice of the appropriate ingredients, and several outdoor and indoor accelerated weathering tests are needed to predict the articles' lifetime.
Chemistry and Materials Science, Polymers and Plastics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
