【導(dǎo)讀】通過合成新型聚醚多元醇及對配方的優(yōu)化試驗，解決了HFC-245fa聚氨酯硬質(zhì)泡沫塑料。冷藏集裝箱及建筑、交通運輸、石油化工管道、軍用航空等諸方面。于上世紀(jì)二十年代末發(fā)展起來的CFC. 但不幸的是，正是由于CFC化合物這一極其重要的穩(wěn)定性，使其能夠在大氣中長。期存在，透過大氣對流層，到達大氣臭氧層。并且由于CFC化合物中的氯元素能與臭氧發(fā)生反應(yīng)，大量。CFC化合物的生產(chǎn)和使用，將導(dǎo)致大氣臭氧層的減少，破壞地球生態(tài)環(huán)境。發(fā)達國家已經(jīng)禁用CFC物質(zhì)，發(fā)展中國家也即將禁用CFC物質(zhì)；聚氨酯硬質(zhì)泡沫塑料是。第一種方案隨著CFC-11的全面禁用即將被廢止；第二種方案因HCFC-141b臭氧消耗潛值。其導(dǎo)熱系數(shù)較高，從而限制了其應(yīng)用范圍，一般只用于管道保溫等領(lǐng)域。各類應(yīng)用試驗已取得重要突破。HFC-245fa在聚醚多元醇中的溶解性總體來說是不錯的。HFC-245fa對冰箱內(nèi)襯材料ABS板和HIPS板均無腐蝕作用，因此在使用HFC-245fa作發(fā)泡劑時，無需。10秒，隨后倒入模具中，使其發(fā)泡。待泡沫熟化徹底后測定其性能。

　　

【正文】 ent in polyethers. In HFC245fa blown system, the foaming theories are different between HFC245fa and H2O, although they both can provide foaming gas. HFC245fa is a physical blowing agent and provides gas through gasification, whiling H2O is a chemical blowing agent and provides gas (CO2) through reacting with isocyanate. In the experiment, we find that foam surface will bee crisp whether water dosage is too high or not as the free rise density fixed. This can be explained as follows: when water dosage is too high, urethane (the reaction product of water and isocyanate) content will increase, inducing in foam surface being crisp。 when water dosage is too low, HFC245fa dosage will increase, much heat will be taken away with gasification of HFC245, inducing in free isocyanate content increasing, which affects foam adhesive performance. Through a lot of experiments, brittleness of foam surface and adhesive performance has been greatly improved by controlling water content in a suitable level. At this level, urethane content is controlled in a certain range, and the released heat also partly makes up the heat sumption of HFC245fa gasification. Improving in Foaming Processing As boiling point of HFC245fa is relatively low, blend positions have blown in the mixing head, reducing in too high viscosity, which affects foam flowing in iceboxes or boards. In the experiment, we choose a cocatalyst mixed at a certain ratio with anic metal salt, hexanhydrogentriazine and dimethylcyclohexanamine. In the first reactive period, this cocatalyst can efficiently restrain physical foaming and avoid foam bining due to fast gasification of HFC245fa。 in the middle period, it can hold the balance between foaming and gelling, resulting in the increasing speed of blend viscosity decreased and enduing foam good flowability。 in the last period, it can effectively promote the reaction between polyether polyol and isocyanate and the tripolymerization of isocyanate, resulting in curing reaction promoted and free isocyanate content decreased. At the same time, raw materials such as PAPI have been filtrated in the experiment. By the filtration of raw materials, we develop polyether blend HY61. Tested by Chinese Electricity Research Institution, parameters of polyether blend HY61 and performances of foam products have reached the same level paring with CFC11 foams. Table 3. Contrast on Examine Indexes between HY61and NAHY21 Specification HY61 NAHY21 Foam Density /kg m－ 3 Thermal Conductivity /mW (m K)1 Closed Cells /% 92 93 Compressive Strength/kPa Elongation Strength/kPa Clinging Strength/kPa Water Absorptivity (V/V)/% 3 3 Hightemperature Dimensional Stability(100℃ ,48h) /% Lowtemperature Dimensional Stability(－ 40℃ ,24h)/% 5. CONCLUSIONS Through filtration of polyether polyols, catalyst, stabilizer etc. and optimizing formulation, parameters of 2020 中國聚氨酯行業(yè)整體淘汰 ODS 國際論壇論文集 327 polyether blend HY61 and performances of foam products have reached (or approached) the same levels paring with CFC11 foams. By the application tests in miniature, we have proved that polyether blend HY61 can satisfy procreative needs and can be popularized in Chinese PU industry. 6. PREFERENCES 1. Production Explanation of HFC245fa, Alliedsignal Co., 1997. 2. Doerge H P., New Developments in HFC245fa Appliance Foam, In: Polyurethanes World Congress39。97, Bayer Co., 1997. 3. Tsukida N, Sato H, Aoyagi M, et al. New Polyols and Formulations for EnergySaving Insulation Using HFC245fa As Blowing Agent, In: Polyurethanes World Congress39。97, Asahi Glass Co. Ltd., 1997. 4. Yu Wenjie, Application Research on HCFC141b, In： Proceedings of the Fourth Congress of Chinese Polyurethane, Beijing, . 5. Liu Xianming, Wang Dan, Blowing Agent─ HFC245fa, Polyurethane Industry, 1998, (2): 5. 6. Li Shaoxiaong, Zhu yuming, Polyurethane Resin, Jiangsu Technology Publishing Company, Nanjing, . 7. Song Jianguo, Zhang Qingwei, Kong Xinping, The Latest Development in CFC Replacement Technology, Chemical New materials, 2020, (8): 20. 8. Kawen F Mansferid, Liu Yiji, New Additive Used in PURF with New BlowingAgent, Proceedings of the Second Congress of Chinese Polyurethane, Beijing, .