Flame-retardant polystyene composition

Abstract

The invention relates to a polystyrene composition comprising a polystyrene and compound according to formula (III).

Claims

1. A polystyrene composition comprising polystyrene and a compound according to formula (III), ##STR00008##

2. The polystyrene composition according to claim 1, wherein the amount of the compound (III) is 1-10 wt % of the total composition.

3. The polystyrene composition according to claim 1, wherein the polystyrene composition is an expandable polystyrene composition.

4. A compound according to Formula (III), ##STR00009##

5. A process for the preparation of the compound according to claim 4, comprising: (i) reacting phenyl dichlorophosphate and p-cresol in the presence of triethylamine and (ii) reacting pyrrolidine and the reaction product of step (i) to obtain the compound of formula (III).

6. The polystyrene composition of claim 1, further comprising a polyphenylene ether resin.

Description

EXAMPLES

(1) Phosphate amine esters were synthesized from phenyl-dichlorophosphate by the replacement of one of the chlorines by a substituted alcohol and the other chlorine by a secondary amine, see FIG. 1 showing the reaction scheme for the preparation of the phosphate amine esters.

Example 1

Preparation of diethyl[(4-methylphenoxy)(phenoxy)phosphoryl]amine (formula (II))

(2) Phenyl dichlorophosphate (5 g, 23.7 mmol) was dissolved in THF (100 ml) and was cooled in an ice-bath to <10 C. Triethylamine (4.8 g, 47.4 mmol) and p-cresol (2.55 g23.6 mmol) was added and the solution was stirred for 2 hours at room temperature. Diethylamine (1.72 g, 23.6 mmol) was added drop-wise and the reaction mixture was stirred overnight at room temperature. Water (50 ml) and ethyl acetate (100 ml) was added and the phases were separated. The organic phase was washed with water, filtered through a plug of silica and evaporated to yield 4.6 g product as oil.

(3) .sup.1H NMR (CDCl.sub.3, ppm) 7.05-7.40 (9H, m, aromatic protons), 3.35 (4H, m, CH2CH3), 2.3 (3H, s, OCH3), 1.76 (6H, m, CH2CH3). .sup.13C NMR (CDCl.sub.3, ppm) 151 (1C) 149 (1C), 134 (1C) 130 (2C), 129 (2C), 124 (1C), 120 (2C), 119 (2C), 39 (2C), 21 (s, 1C), 14 (s, 2C).

(4) ##STR00006##

Example 2

Preparation of 4-methylphenyl phenyl pyrrolidin-1-ylphosphonate (formula (III))

(5) Phenyl dichlorophosphate (5 g, 23.7 mmol) was dissolved in THF (100 ml) and was cooled in an ice-bath to <10 C. Triethylamine (4.8 g, 47.4 mmol) and p-cresol (2.55 g 23.6 mmol) was added and the solution was stirred for 2 hours at room temperature. Pyrrolidine (1.68 g, 23.6 mmol) was added drop-wise and the reaction mixture was stirred overnight at room temperature. Water (50 ml) and ethyl acetate (100 ml) was added and the phases were separated. The organic phase was washed with water, filtered through a plug of silica and evaporated to yield 7 g product as oil.

(6) .sup.1H NMR (CDCl.sub.3, ppm) 7.05-7.35 (9H, m, aromatic protons), 3.25 (4H, t, CH2CH3), 2.35 (3H, s, OCH3), 1.05 (6H, m, CH2CH3). .sup.13C NMR (CDCl.sub.3, ppm) 152 (1C) 148 (1C), 134 (1C) 130 (2C), 129 (2C), 125 (1C), 120 (2C), 119 (2C), 47 (2C), 27 (2C), 21 (1C).

(7) ##STR00007##