求翻译：TDI与PPG等摩尔反应：准确称量等摩尔的TDI和PPG置于带有回流冷凝器及搅拌器的250mL四口瓶中，在氮气保护下加热至50~70℃，滴加0.04% 有机锡混合催化剂溶液，反应3~4h，定时取样供测试-NCO含量，具体测试见2.2.3方法。是什么意思？

Equimolar reaction of TDI and PPG: accurate weighing equimolar TDI and PPG with a reflux condenser and placed in a 250mL four stirrer bottle, under nitrogen heated to 50 ~ 70 ℃, dropping 0.04% organic tin mixed catalyst solution, the reaction 3 ~ 4h, regular sampling for test-NCO content, see the sp

With such as TDI PPG Moore Moore response such as: accurate measurement of PPG TDI and placed in a return of 250 Condenser and blender mL 4 bottle mouth in heated under protection, and the nitrogen gas to 50 ~ 70 °C drops, plus 0.04 % nitric acid, organic Tin mixed catalyst 3 ~ 4H reaction, regular

TDI and PPG and so on mole of response: The accurate weighing and so on mole of TDI and PPG put in have the reflux condenser and in the mixer 250mL four bottles, heats up under the nitrogen protection to 50~70℃, adds by drops 0.04% organic tin mixed catalyst solution, responds 3~4h, fixed time takes

Such as PPG, TDI of molar reaction: accurate weighing of Moore's TDI and PPG at 250mL with a reflux condenser and mixers in four bottles, heated to 50~70℃ under nitrogen protection, spot 0.04% organic Tin mixed catalyst solution, reaction 3~4H, sampling for testing scheduled-NCO content, see 2.2.3 m

Such as PPG, TDI of molar reaction: accurate weighing of Moore's TDI and PPG at 250mL with a reflux condenser and mixers in four bottles, heated to 50~70℃ under nitrogen protection, spot 0.04% organic Tin mixed catalyst solution, reaction 3~4H, sampling for testing scheduled-NCO content, see 2.2.3 m