化學發泡基礎實驗

本研究將探討兩種化學發泡的實驗研究，第一種為通用級聚苯乙烯（General Purpose Polystyrene；GPPS）利用化學發泡劑（Chemical blowing agent；CBA），分別為吸熱及放熱型發泡劑，第二種將探討聚氨酯（Polyurethane;PU）化學發泡的研究結果。先將探討聚苯乙烯添加化學發泡劑，使用田口式L9直交表規劃實驗，經由一次一因子法實驗分析結果，探討不同製程參數下對於抗拉強度之影響，參數分別為分散油含量、發泡劑添加量、射出速度以及料溫，再以田口式實驗法將實驗參數做一個完整的規劃，找到相關製程參數下對彼此的影響性。研究結果顯示，吸熱型發泡劑機械性質部分，分散油含量為10 cc、發泡劑添加量為2 wt、射出速度為80 cm3/s、料溫為200℃時，其拉伸強度是最好的，而放熱型發泡劑機械性質部分，分散油含量為15 cc、發泡劑添加量為0.5 wt、射出速度為100 cm3/s、料溫為200℃時，其拉伸強度是最好的；田口實驗部分經由一次一因子研究中得知，發泡劑的添加量為最重要的影響因子，其次為料溫。另一項研究實驗將探討聚氨酯化學發泡的研究結果，觀察在不同模溫下的流動長度、壓力以及溫度。實驗發現發泡長度會會隨著模溫提高而長度變長，30℃的發泡長度是6.7 cm，40℃是7.96 cm，50℃是10.13 cm。但是溫升隨著模溫的提高而溫升下降，30℃的溫升是22.08℃、40℃的溫升是14.28℃、50℃的溫升是11.93℃，壓力的趨勢和溫升一樣，30℃的壓升是1.09 bar，40℃的壓升是0.8 bar，50℃的壓升是0.74 bar。可見模溫愈高，利於交聯反應。

關鍵字

聚苯乙烯；聚氨酯；化學發泡劑；田口方法；射出成型

並列摘要

Chemical foaming is a cheap and efficient method to make polymer foam. Although it is environmental unfriendly but it is cheap and popular. This study investigated chemical blow agent (CBA) foaming and Polyurethane (PU) foaming. There are two kind of CBA namely exothermic and endothermic CBAs. Exothermic is the most efficient and popular material in the market. Polymer used for CBA foaming is Polystyrene (PS). Taguchi method, L9, orthogonal was used in the CBA foaming. Process parameters of dispersed oil loading, CBA amount, injection speed and melt temperature were used to study their effects on the tensile strength of PS foam. The results showed it had the best tensile strength with process condition of 10 c.c. dispersed oil, 2 wt.% of CBA, injection speed of 100 cm3/s, and melt temperature of 200 ℃ for endothermic foaming. While it was 15 c.c. dispersed oil, 0.5 wt.% of CBA, injection speed of 100 cm3/s, and melt temperature of 200 ℃ for exothermic foaming. The most effective parameter for tensile strength was CBA amount and melt temperature was the second one both for exothermic and endothermic foaming. The PU foams are cellular materials synthesized by the reaction of diisocyanate with polyol in the presence of a water blowing agent. The process condition of mold temperature and material temperature were used to study their effects on the flow length, pressure, and PU temperature for PU foaming, Results showed that flow length increased with increasing mold temperature. The flow length is 6.7, 7.96, and 10.13 cm for mold temperature of 30, 40, and 50 ℃respectively. However the temperature rising decreased with increasing mold temperature. The temperature rising is 22.08, 14.28 and 11.93 ℃ for mold temperature of 30, 40, and 50 ℃respectively. Pressure rising had the same trend as temperature rising did, It is 1.09, 0.8, 0.74 bar for mold temperature of 30, 40, and 50 ℃ respectively.