Technical Papers
Technical notes are published by Baisha to supplement our technical
advisory information.
PVC Stabilizers of the Past, Present, and Future
R. D. Doworkin
First published: March 1989
Abstract: When chemical additives were found that could minimize the loss of chemical and physical properties of a thermally-processable but heat-sensitive polymer called poly(vinyl chloride) (PVC), an industry was born. And with it grew the world of plastics additives. Stabilizers for PVC became and industry itself, feeding into and off of this versatile polymer industry, in an almost symbiotic relationship. There have been so many types of stabilizers in use throughout the past fifty years: inorganics, leads, organics, barium/cadmiums, calcium/zincs, organotins, and antimony. And so very many more have been conceived but not commercialized: organoleads, organoantimonys, bismuths, indiums, and a myriad of organic chemicals. What are the merits and deficiencies of these stabilizers? What of yesterday’s products are still with us? What are the newer types? What might be tomorrow’s products? This paper will attempt to review and discuss the past, present, and future of PVC stabilizers; the factors that are responsible for their variety, for influencing their research, development, and commercialization, and how these factors change with time.
Weatherable rigid PVC: The Effect of Light and Thermal Stabilizers
Gerald Capocci
First published: December 1989
Abstract: Rigid PVC compositions used in outdoor applications such as siding, profiles, windows, and soffit predominantly contain a tin mercaptide thermal stabilizer. It is well known that tin mercaptides impart outstanding thermal stability to vinyl compounds, however, it is also well known that they provide only marginal light stability. Mercaptides can be used in these applications primarily because they are combined with high levels of titanium dioxide. They are not well suited for dark colored PVC and compositions without titanium dioxide. These require a more weatherable thermal stabilizer, such as a tin carboxylate. In this paper, principles for formulating rigid weatherable vinyl will be discussed. The influence of thermal stabilizers and the interdependence of light stabilizers and thermal stabilizers on PVC photostability will be emphasized. Data will be presented showing how one can formulate weatherable dark brown and pastel PVC through the use of tin carboxylate thermal stabilizers, the appropriate light stabilizers, and pigments. Traditional approaches to achieving weatherability will be compared to what can be attained by capitalizing on the latest advances in stabilization technology. Finally, methods for reducing TiO2 concentration will be shown.
Trends and Prospects for Thermal Stabilizers in Polyvinyl Chloride
Degang Li, Pengjia Liu
First published: 17 October 2022
Abstract: Thermal stabilizers are essential for polyvinyl chloride (PVC) processing. It is the emergence of thermal stabilizers that made PVC’s applications migrate from laboratory to large-scale industrial use. Herein we overview the development status of some traditional thermal stabilizers including lead salt, metal soaps, and organotin along with relatively newer thermal stabilizers such as organic thermal stabilizers and metal alkoxides. Taking into consideration the high market demand, opportunities for cost-effective additives for thermal stabilizers are also briefly discussed. Finally, with the recent shift in focus on thermal stabilizer synthesis and their performance characterization but neglecting mechanical property testing and verification, we put forward application prospect of quantum chemical calculation for the development of PVC thermal stabilizers.