RAFT反应制备阳离子丙烯酸酯改性环氧树脂乳液毕业论文_化学工程与工艺毕业论文

RAFT反应制备阳离子丙烯酸酯改性环氧树脂乳液毕业论文

2021-04-28更新

摘 要

阳离子乳液是一种带正电荷的聚合物乳液,这种乳液可用于浸渍织物,有不怕硬水及在酸性条件下应用等特点,有着广阔的应用前景。通过现阶段研究较热的RAFT反应进行聚合,在聚合体系中加入链转移常数高的特种链转移剂,使得增长自由基和该链转移剂之间进行退化转移,从而实现活性自由基聚合。本文通过RAFT可控有序聚合,制备了RAFT反应阳离子丙烯酸酯改性环氧树脂乳液。

本文共进行了以下几种研究:1.以正十二硫醇、丙酮、CS2和2-溴代异丁酸为原料,常温下反应16h后,经过多次萃取过滤及重结晶制得RAFT试剂正十二烷基三硫代碳酸酯。2.使用四丁基溴化铵为催化剂,将RAFT试剂与E-51在100℃下反应制得RAFT环氧酯。3.以RAFT环氧酯为原料,引入甲基丙烯酸二甲胺乙酯(DM)、苯乙烯(St)两种单体,偶氮二异丁腈(AIBN)为引发剂,制备乳化剂。研究最佳工艺条件为:反应温度为100℃,反应时间为为8h,引发剂AIBN用量(以反应物总质量计)为1.8%4.在制得的乳化剂基础上再引入苯乙烯(St)及丙烯酸丁酯(BA)两种单体,测得以H2O2为最优引发剂在,制得带正电荷的聚合物乳液,即阳离子乳液。通过对产物的酸值计算及固含的测定,算出反应的转化率并用红外光谱和核磁共振氢谱对产物结构进行了表征。

试验结果表明,引发剂选用H2O2时转化率能达到最佳为93.7%,且最佳反应温度为85℃,考虑到工厂生产效率,反应1h制备的乳化剂效率最高,本文还探讨了不同引发剂对制备乳液转化率的影响,不同用量的乳化剂对乳液水溶性的影响。

关键词:水性环氧树脂;丙烯酸酯改性;RAFT;阳离子乳液

Preparation of cationic acrylate modified epoxy resin emulsion by RAFT reaction

ABSTRACT

Cationic emulsion is a positively charged polymer emulsion. It can be used to impregnate fabrics. It has the characteristics of not being afraid of hard water and application under acidic conditions. It has broad application prospects. The polymerization is carried out by the hot RAFT reaction at the present stage, and a special chain transfer agent having a high chain transfer constant is added to the polymerization system to cause degradation transfer between the growth radical and the chain transfer agent, thereby realizing living radical polymerization.

In this paper, the following studies were carried out: 1. Using n-dodecyl mercaptan, acetone, CS2 and 2-bromoisobutyric acid as raw materials, after 16 hours of reaction at room temperature, RAFT reagent was obtained after multiple extraction filtration and recrystallization. N-dodecyltrithiocarbonate. 2. RAFT epoxy ester was prepared by reacting RAFT reagent with E-51 at 100 ° C using tetrabutylammonium bromide as a catalyst. 3. Using RAFT epoxy ester as raw material, dimethylamine ethyl methacrylate (DM) and styrene (St) monomers were introduced, and azobisisobutyronitrile (AIBN) was used as initiator to prepare emulsifier. The optimum process conditions were as follows: the reaction temperature was 100 ° C, the reaction time was 8 h, and the amount of initiator AIBN (based on the total mass of the reactants) was 1.8%. 4. Styrene was introduced on the basis of the prepared emulsifier. And butyl acrylate (BA) two monomers, measured H2O2 as the optimal initiator at 85 ° C for one hour to produce a positively charged polymer emulsion, namely cationic emulsion. The conversion of the reaction was calculated by calculating the acid value of the product and the determination of the solid content, and the structure of the product was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy.

The test results show that the conversion rate of the initiator is up to 93.7% when the initiator is selected, and the optimum reaction temperature is 85 °C. Considering the production efficiency of the plant, the emulsifier prepared by the reaction for 1 hour has the highest efficiency. Different initiators are also discussed in this paper. The effect on the conversion of the emulsion, the effect of different amounts of emulsifier on the water solubility of the emulsion.

Key words: waterborne epoxy resin; acrylate modification; RAFT reaction; Cationic emulsion

目录

RAFT反应制备阳离子丙烯酸酯改性环氧树脂乳液

摘 要

目录

1.前言 1

1.1可逆加成—断裂链转移活性自由基聚合(RAFT) 1

1.1.1 RAFT聚合机理 4

1.1.2 RAFT试剂的结构特点 6

1.1.3实现“活性”/可控RAFT聚合的条件 7

1.1.4 RAFT聚合引发方法   8

1.2 RAFT聚合的特点及应用 8

1.2.1.RAFT聚合的优缺点 8

1.2.2 RAFT聚合应用于材料改性 9

1.2.3.RAFT聚合方法合成两亲性聚合物 10

1.3.环氧树脂 11

1.3.1环氧树脂的应用 11

1.3.2.丙烯酸树脂改性 11

1.3.3环氧树脂水性化的制备方法 11

1.3.4.外加乳化法 12

1.3.5.自乳化法 12

1.3.6通过化学改性的方法改性环氧树脂 13

1.4 本文研究的目的内容及创新点 15

2实验部分 16

2.1实验内容 16

2.1.1实验主要设备 16

2.2实验步骤 17

2.2.1制备RAFT试剂 17

2.2.2 制备RAFT环氧酯 18

2.2.3 制备乳化剂 19

2.2.4 制备乳液 21

2.3测试与表征 22

2.3.1酸值的测定 22

2.3.2固含的测定 22

3 结果与讨论 23

3.1 反应的影响因素 23

3.1.1 反应时间对制备乳化剂转化率的影响 23

3.1.2 反应温度对乳化剂转化率的影响 23

3.1.3 引发剂用量对制备乳化剂转化率的影响 24

3.1.4 乳化剂用量对乳液水溶性影响 25

3.1.5 反应时长对制备乳液转化率的影响 26

3.1.6 引发剂种类对制备乳液转化率的影响 27

3.3 产物的表征 27

3.3.1 产物的红外光谱表征 27

3.3.2 产物的核磁共振氢谱表征 29

结论 32

致 谢 33

参考文献 34

1.前言

1.1可逆加成—断裂链转移活性自由基聚合(RAFT)

1998年第一次有相关(可逆加成断裂链转移聚合)的概念被提出,RAFTRizzardo、Moad和Thang(G.Moad, E. Rizzardo, S. H. Thang, Macromolecules 1998, 31, 5559–5562)在1998年正式发表了相关的文献,也正是从这个时候开始这种合成方法突然备受瞩目,大有前景的RAFT就在RDRP(可逆失活自由基聚合)被学术界广泛讨论,众多化工相关学者开始研究这个方向。现代的高分子合成技术我们最重视最需要的也就是RAFT所具有的特性:稳定、适用方向极广。

RAFT的机理与众多我们以前熟知的自由基聚合所去甚远,它是通过链转移来实现我们希望能达到的对反应的可控性。而传统的自由基反应,就比如说(硝基氧-调节聚合)NMP和(原子转移自由基聚合)ATRP[47],这两种的机理是凭借自由基的可逆终止。RAFT聚合本质上想要达到失活-活化平衡的效果是需要加入引发剂的 ,因为只有通过外部加入引发剂的情况下,才能使它的自由基浓度产生变化,因为其本身的自由基浓度是不会变化一直处于平衡状态的。

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