Effects of Surface Modification of Mg(OH) 2 with Polysiloxane Oil and Silica Additive on the Flame Retardancy and Mechan
- PDF / 1,180,110 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 80 Downloads / 197 Views
EE9.35.1
Effects of Surface Modification of Mg(OH)2 with Polysiloxane Oil and Silica Additive on the Flame Retardancy and Mechanical Properties of LDPE-Mg(OH)2 Composites K. Kodama1,2, T. Hyodo3, Y. Shimizu1 and M. Egashira3 1 Graduate School of Science and Technology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan 2 YAZAKI Parts Co., Ltd., 1500 Mishuku Susono-shi, Shizuoka 411-1194, Japan 3 Faculty of Engineering, Nagasaki University, 1-14 Bunkyou-machi, Nagasaki 852-8521, Japan
ABSTRACT Composites of low density polyethylene (LDPE) and 40 wt% Mg(OH)2 modified with several kinds of polysiloxane oils were prepared in order to evaluate the effect of the surface modification of Mg(OH)2 on the mechanical properties and oxygen index of the composites. A composite containing Mg(OH)2 modified with methylhydrogen polysiloxane oil showed an oxygen index of 23.8% O2 and an elongation of 425%. These values were superior to other composites containing Mg(OH)2 modified with other kinds of polysiloxane oils. The oxygen index could be enhanced up to 24.8% by co-addition of 5 wt% fumed silica as another flame retardant to the composite of LDPE and 35 wt% Mg(OH)2 (modified with methylhydrogen polysiloxane oil), while fixing the total amount of the flame retardants at 40 wt%.
INTRODUCTION Magnesium hydroxide, Mg(OH)2, is well known as an effective flame retardant for polymers, since it does not produce any corrosive and toxic gases during its decomposition upon firing [1,2]. Oxygen index of polymer-Mg(OH)2 composites can be enhanced by increasing the additive amount of Mg(OH)2, but excess addition of Mg(OH)2 results in a decline of mechanical properties, such as tensile strength and elongation, of the composites. Therefore, special attention has been paid on the surface modification of Mg(OH)2 particles which enables us to realize a high loading level while maintaining the sufficient mechanical properties [3-5]. The present study has been directed to modifying the surface of Mg(OH)2 particles with several kinds of polysiloxane oils, in order to develop a more effective flame retardant for low density polyethylene (LDPE)-based composites. Then the mechanical properties and oxygen index of the composites have been investigated. Effect of co-addition of fumed silica, as
EE9.35.2
another flame retardant, on the properties of the composites was also tested, while maintaining the total amount of the flame retardants to be 40 wt%.
EXPERIMENTAL Materials LDPE (Mirason 3530, density is 0.924 g/cm3) purchased by Mitsui Chemical Co., Ltd. was used as a base polymer. Untreated (Magnifin H5) and stearic acid-treated magnesium hydroxide (Magnifin H5C) purchased from Albemarle Corp. were used as flame retardants. The particle size of these two commercial products was in the range of 1.25-1.65 µm. Magnifin H5C was used without any additional treatment, while Magnifin H5 was subjected to surface modification with different kinds of polysiloxane oils supplied by Dow Corning Toray Silicone Co., Ltd. before use. Hydrophobic fum
Data Loading...
