Synthesis of zinc hydroxystannate microcapsule for improving flame retardancy and smoke suppression of poly(lactic acid)

In this paper, zinc hydroxystannate (ZHS) was microencapsulated by aluminium phosphate (AlP) to prepare AlP/ZHS microcapsule, it was introduced into polylactic acid (PLA). The flammability of the PLA was characterized by limiting oxygen index (LOI), vertical burning (UL-94), smoke density (SDR) and cone calorimeter test. The results showed that PLA containing 15 wt% AlP/ZHS microcapsule achieved the LOI value of 32.5%, passed the UL-94 V-0 rating, and significantly decreased the peak heat release rate, which imply that the fire safety of PLA has been improved. Meanwhile, the SDR value reached 44%. Thus, AlP/ZHS microcapsule can effectively enhance flame retardancy and smoke suppression, showing potential applications as multifunctional advanced composites. (C) 2017 Elsevier B.V. All rights reserved.