Functional polymer nanospheres prepared with reactive and biodegradable polymer surfactant

本研究的主要目的是合成一种反应性和可生物降解的聚合物表面活性剂，并建立一种适用于控制非均相聚合法制备的聚合物纳米球表面性能的技术。得到了以下结果：成功合成了具有自由基聚合潜力的部分含乙烯苄基的聚天冬氨酸活性高分子表面活性剂。利用合成的聚合物表面活性剂与苯乙烯进行乳液共聚，得到了粒径为200 ~ 400 nm的分散稳定的聚合物纳米球。结果表明，通过改变聚合过程中的配方，可以控制聚合物的直径。用乳液共聚法制备的聚合物纳米球表面覆盖了聚天冬氨酸衍生物，ζ电位测量值为-40 mV。认为这种高z电位与聚天冬氨酸高分子的羧基有关。用合成的聚天冬氨酸高分子聚合物作为反应分散剂，与苯乙烯进行分散、共聚，得到了更小的聚合物纳米球。制备的聚合物纳米球直径控制在35 ~ 150 nm之间。聚天冬氨酸大分子的浓度、乙烯基苯基引入度和主链分子量是影响聚合物纳米球直径的重要参数。当合成的聚天冬氨酸大分子单体形成分子间缔合时，聚天冬氨酸大分子单体进行了均聚，制备了更小的纳米球。结果表明，聚合物纳米球的直径为10 ~ 30 nm。由聚天冬氨酸衍生的活性高分子表面活性剂与苯乙烯进行非均相共聚，成功地将聚合物纳米球的直径控制在10 ~ 400 nm之间。

The paramount objective of this research is to synthesize a reactive and biodegradable polymer surfactant and to establish the technique applicable to the control of surface properties of polymer nanospheres prepared by heterogeneous polymerization with the synthesized surfactant. The following results were obtained.l. We successfully synthesized the reactive and biodegradable polymer surfactant of polyaspartate partially bearing vinyl benzyl moiety which had a potential of radical polymerization.2. Emulsion copolymerization with styrene using the synthesized polymer surfactant provided stably-dispersed polymer nanospheres with a diameter of 200〜400 nm. The diameter was found to be controllable by changing a recipe in polymerization.3. Polymer nanospheres prepared by emulsion copolymerization was covered with polyaspartate derivative from a view point of ζ-potential measurement which was -40 mV. It was considered that this high z-potential was contributed to carboxyl group of polyaspartate macromer.4. Dispersion, copolymerization with styrene using the synthesized polyaspartate macromer as a reactive dispersant gave smaller polymer nanospheres by emulsion copolymerization. The diameter of the prepared polymer nanospheres was controlled between 35〜150 nm.5. The concentration of polyaspartate macromer, the introduction degree of vinyl benzyl moiety and the molecular weight of main chain were found to be significant parameters affected diameter of the prepared polymer nanospheres.6. As the synthesized polyaspartate macromonomer formed intermolecular association, homopolymerization of polyaspartate macromer was conducted to prepare much smaller nanospheres. The result was suggested the formation of polymer nanospheres with a diameter of 10〜30 nm.7. By heterogeneous copolymerzation of styrene with the reactive and biodegradable polymer surfactant derived from polyaspartate, we can successfully control a diameter of polymer nanospheres with a range between 10〜400 nm.