Properties of high impact polystyrene flame retarded by magnesium hydroxide
and modified with triblock copolymer styrene/butadiene/styrene
Polimery 2005, No 3, 190
Mechanical, combustible and smoke properties of two series of high impact polystyrene (PS-HI) compositions differing in the content of flame retardant [Mg(OH)2] and amount of a modifier (SBS) mentioned in the title. In the first series of experiments [50 wt. % of Mg(OH)2] it has been found that modification with 15 wt. % of SBS causes significant increase in impact strength (U) and decrease in maximum strength (Ru), Young modulus (E) and hardness (HK). Also oxygen index (OI) deteriorated. Decreases in values of exposure (S) and illumination at fourth minute (E4) show the increased smoke evolution. In the other series of experiments Mg(OH)2 content was increased up to 55 wt. % and various amounts of SBS were used (4.5, 13.5 or 22.5 wt. %). It was observed that U and Ru increased with SBS content increase while E and HK lowered clearly. Increase in modifier amount positively influenced OI and improved smoke properties. Flame retardant used caused that the plastic did not melt and did not flow as burning drops. None of the samples was burnt despite small thickness (5 mm).
Key words: high impact polystyrene, flame retardation, magnesium hydroxide, copolymer styrene/butadiene/styrene, mechanical properties, oxygen index, smoke intensity
Properties of high impact polystyrene flame retarded by magnesium hydroxide and modified with triblock copolymer styrene/butadiene/styrene