| 配方类型： |
RUBBER, PLASTICS, WAXES |
| 配方说明： |
Polyester A |
| 配方组成： |
Ethylene Glycol/1024 g
Maleic Anhydride/1471 g |
| 配制方法： |
Charge the ethylene glycol. Start the agitator and introduce a slow stream of inert gas (nitrogen or carbon dioxide). Heat to about 80'C, add the maleic anhydride, which will melt almost immediately, and mix with the glycol to give a clear limpid liquid. Increase the temperature to 180'C over about 3 hours. Around 100'C, an exothermic reaction usually sets in, which will increase the temperature 10 to 30'C by itself. When this increase is noted, decrease the heating until the reaction is under control. Water of reaction starts to come over at 140 to 150'C. Take samples of the resin once or twice every hour and determine the acid number.
Now increase the temperature to 200'C over a period of 2 hours and then further to 205-210'C. Maintain this temperature until the acid number is less that 50. Cool to about 100'C and add 0.003% of tert-butylcatechol, as inhibitor. When it is dissolved, transfer the resin to a suitable container.
Always use a blanket of inert gas to protect an unsaturated polyester at |
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