- 期刊
利用雙團聯共聚物為界面活性劑之迷你乳化聚合法研究
Miniemulsion Polymerization of Styrene Using a Diblock Copolymer Surfactant
摘要
本研究為利用雙團聯共劇務為界面活性劑，並由迷你油滴穩定性、聚合期間粒子粒徑變化來探討其濃度與結構對迷你乳化聚合反應之影響。雙團聯共聚物是利用基團轉移聚合法(Group Transfer Polymerization, GTP)合成不同比例親疏水段之團聯共聚物，共聚物單體組成包括疏水段的甲基內烯酸甲酯(MMA)及親水段的甲基內烯酸二甲胺乙酯(DMAEMA)。實驗結果顯示界面活性劑濃度越高，迷你油滴越穩定且水相成帳粒子數越多。雙團聯共聚物型界面活性劑對油滴之穩定性主要由疏水段之長短所控制，固定親水段長度為B_(t2)，而增加疏水段長度峙，雙團聯共聚物對於油滴之穩定性阻疏水段長度之增加而變差。但間定疏水段長度為M_(18)時，變化親水段長度其對油滴穩定性影響較小，但仍有團聯共服物結構中親水段/疏水段比例越大，則此雙團聯共聚物對油滴種定性越佳之趨勢。另外雙關聯共聚物M_(12) B_(36)與M_(18)B_(36)對油滴之穩定性與傳統使用之陰離子型界面活性劑SDS有相似之油滴穩定功能。
並列摘要
Series of miniemulsions based on styrene/AIBN in the presence of a diblock copolymer or sodium dodecyl sulfate as the surfactant and hexadecane (HO) as a eosurfactant were developed. The diblock copolymers were synthesized by using group transfer polymerization based on methyl methacrylate and dimethyl aminoethyl methacrylate. Experimental results indicated that the stability of droplets and the number of particle via aqueous nucleation increased with increasing the surfactant concentration in the miniemulsion polymerization. The change of the polymer particle sizes during the polymerization implied that the droplet and the aqueous (micellar or both homogeneous) nucleation occured in the miniemulsion polymerization simultaneous. In addition, the length of a diblock copolyemr with its hydrophobic segment dominated the stability of droplets in miniemulsion systems. Furthermore, when the composition of diblock copolymer was appropriately controlled the diblock copolymer could function as the anionic surfactants (such as SOS) do.