Lead-free stabilization for PVC pipes: The new alternative

摘要

With its outstanding cost performance benefits, PVC remains the material of choice for the construction industry and pipe producers. However, environmental concerns and regulations will lead to the elimination of lead based heat stabilizers over the next five years. This move to lead free stabilizers currently forces pipe producers to re-evaluate their stabilizer options as they strive to keep the cost competitiveness of their PVC formulations. Thus, the challenge for stabilizer manufacturers is to propose new lead-free stabilizers for pipes with good performance and attractive costs. The Rohm and Haas Company has developed a new stabilization system that is based on a derivative of the mercaptan chemistry which has been used for decades with conventional tin stabilizers. The patented technology includes organic based, heavy metal free compositions that contain blocked thiols, which under vinyl processing conditions generate highly active stabilizing components. These innovative systems offer wide processing windows, give excellent earlycolor, and can be adjusted to meet the various technical requirements of the pipe market. The stabilizing systems are odor free, and are compatible with all standard stabilizer systems. Additional benefits include reduced cross-linking leading to easier recycling. These new stabilizing systems are non toxic, contain no heavy metals, and are available as stabilizer additives or as one-packs, offering excellent price/performance ratio. Considering these technical benefits as well as the conclusions ofa stabilizer sustainability assessment, this new technology represents an advanced and more sustainable solution for PVC pipes stabilization. The present article details the stabilization mechanism and performance attributes (stabilization, rheology, and recycling data) on both laboratory and industrial equipment of this new lead-free PVC stabilizer.