• 作者： Chern, Chorng-Shyan; Lin, Shi-Yow; Chang, Shwu-Ching
• 中文摘要： 本研究探討混合型界面活性劑(陰離子型十二烷基硫酸鈉(SDS)/非離子型壬基苯酚四十莫耳環氧乙烷(NP-40)對苯乙烯化聚合反應動力學之影響。以純NP-40(亦即界面活性劑混合物中所含NP-40之重量百分率W(NP-40)=100%)安定之乳化聚合物對溫度相當敏感；當反應溫度上升時，NP-40在安定乳漿粒子的效果上將大打折扣。而當加入些微SDS時，則將使得反應系統之膠體安定性大為提昇。本研究提出一反應模式以定性解釋在反應溫度為60℃與W(NP-40)=0, 50, 90或100%條件下所獲得之動力學以及高分子粒徑分布等實驗數據。當W(NP-40)=100或90%時，在聚合反應初期，有限架橋凝聚在粒子核心形成程序上扮演著重要之角色；反之，當W(NP-40)=0%時，在反應過程中所產生之粒子核心則顯得相當安定。至於當W(NP-40)=50%時，此反應系統則呈現介於兩者之間的粒子成核行為。
• 英文摘要： The effects of the mixed surfactants of anionic sodium dodecyl sulfate (SD6) and nonionic nonylphenol polyethoxylate with an average of 40 units of ethylene oxide per molecule (NP-40) on the reaction kinetics of the styrene emulsion polymerization were investigated. The polymerization rate is faster for the reaction system stabilized by the mixed surfactants with the wt% NP-40 in the surfactant mixture W (NP-40)=50 or 90% as compared to the system stabilized only by SDS or NP-40 (W(NP-40)=0 or 100%). In addition, the effectiveness of NP-40 to stabilize the latex particles is greatly reduced as the reaction temperature (T) is increased. However, incorporation of a small amount of SDS into the reaction system makes it insensitive to T. A reaction scheme was proposed to qualitatively explain the kinetic data and the particle size and particle size distribution data for the runs with various levels of W(NP-40) at 60 t. During the very early stage of polymerization, limited bridging flocculation plays an important role in the nucleation of latex particles for the runs with W(NP-40)=100 and 90%. On the other hand, the nucleated particles are relatively stable for the run with W( NP-40)=0%. The run with W(NP-40)=50% shows an intermediate particle nucleation behavior.
• 中文關鍵字： 乳化聚合; 界面活性劑; 反應動力學; 苯乙烯乳化; 粒徑分布
• 英文關鍵字： Emulsion Polymerization; Sulfactant; Reaction Kinetics; Polystrene Latex; Particle Size Distribution