China Plastics ›› 2024, Vol. 38 ›› Issue (1): 86-91.DOI: 10.19491/j.issn.1001-9278.2024.01.012

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Study on properties of modified ammonium polyphosphate coated with polysiloxane and its flame retardancy on polyethylene

ZHAO Xiaobo1, WANG Guotai2, LIANG Shujun3()   

  1. 1.School of Materials Science and Engineering,North University of China,Taiyuan 030051,China
    2.Department of Materials Engineering,Taiyuan Institute of Technology,Taiyuan 030008,China
    3.Discipline Construction Office,Taiyuan Institute of Technology,Taiyuan 030008,China
  • Received:2023-07-23 Online:2024-01-26 Published:2024-01-22

Abstract:

The microencapsulation modification of ammonium polyphosphate (APP) was performed to prepare the modified APP/DMDES, APP/MTES, and APP/PTMS for enhancing their flame retardancy, thermal stability and hydrophobicity through a sol⁃gel process using tetraethylorthosilicate (TEOS) as a main precursor and dimethylldiethoxysilane (DMDES), methyltriethoxysilane (MTES), and phenyltrimethoxysilane (PTMS) as co⁃precursors. The structures and performance of the resulting APP coated with polysiloxane was investigated by using Fourier⁃transformation infrared spectroscopy, water contact angle, scanning electron microscope, energy dispersive spectrometer, and thermogravimetric analysis. The effects of modified APP on the flame retardancy, mechanical and thermal properties of low⁃density polyethylene (PE⁃LD) were also studied. The results showed that polysiloxane⁃coated modified APP could be prepared under suitable processing conditions, and its hydrophobicity and thermal stability of the modified ammonium polyphosphate were significantly improved compared to pristine APP. As a PE⁃LD/APP/PTMS/pentaeritritol/melamin mass ratio of 65/18.7/11.7/4.6, the PE⁃LD composite exhibited the best overall performance with a limiting oxygen index of 26.6 vol%, which is 23.3 % higher than that of pristine APP. The composite also reached a UL 94 V⁃0 level in the vertical burning test and obtain the highest tensile strength of 12.84 MPa.

Key words: ammonium polyphosphate, polysiloxane, microencapsulation, low?density polyethylene, flame retardancy

CLC Number: