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1、核壳乳液聚合核壳乳液聚合核壳乳液聚合核壳乳液聚合 1优质课Company name核壳乳液聚合1 1什么是核壳乳液聚合2 2核壳乳液聚合的核壳结构3 3影响核壳乳液聚合的因素4 4核壳乳液聚合运用举例2优质课Company name什么是核壳乳液聚合核壳乳液聚合核壳乳液聚合是种子乳液聚合的发展。若种子聚合和后继聚合采用不同单体，则形成核壳结构的胶粒，在核与壳的界面上形成接枝层，增加两者的相容性和粘结力，提高力学性能。在总配比完全相同的情况下，因为组分性质的差异，采用种子乳液聚合的方法，控制不同的加料顺序和条件，可以得到结构形态不同的核壳乳胶粒子。与普通乳液乳液聚合相比，它有显著的优越性，如在流
2、变性、最低成膜温度、玻璃转化温度、抗张强度、粘接性能、加工性等方面有显著的特点。4优质课Company name什么是核壳乳液聚合种子乳液聚合核壳乳液聚合使粒子长大后继的正式聚合采用同一种单体少量单体先形成种子胶乳形成核壳结构后继聚合采用不同单体少量单体先形成核结构部分5优质课Company name核壳乳液聚合的核壳结构6优质课Company name核壳乳液聚合的核壳结构单体液滴单体液滴种子胶乳单体、乳化剂分别处在水溶液、胶束、液滴三相中的示意图7优质课Company name影响核壳乳液聚合的因素根据核和壳单体的不同，正常的核壳聚合物基本上有两种类型：硬核软壳型：这类聚合物主要用作涂料。
3、软核硬壳型：调节玻璃化温度或最低成膜温度。以丁二烯丙烯酸丁酯等软单体，经乳液聚合后为种子，甲基丙烯酸甲酯苯乙烯丙烯睛等为硬单体，后来加入继续聚合，就成为硬壳层。以B（聚丁二烯）为核，S（苯乙烯）和A（丙烯氰）共聚物为壳，就成了著名的ABS工程塑料。8优质课Company name影响核壳乳液聚合的因素核壳乳液粒子构成机理接枝机理一种单体在另一种聚合物存在下进行聚合时，在适当的条件下，会多去聚合物上的活泼氢原子而发生接枝共聚。如St-BA核壳乳液聚合互穿聚合物网络机理两种聚合物分子链相互贯穿并以化学键的方式各自交联而成的网络结构离子键合机理不同电荷的相互作用9优质课Company name影响核
4、壳乳液聚合的因素壳层物质的壳层物质的加料方法加料方法不同，不同，形成的核壳结构和核壳间结合方式也差别很大。形成的核壳结构和核壳间结合方式也差别很大。溶胀法：先不补加引发剂，而加入壳单体，使壳单体溶胀进入乳胶内。这种方法不仅种子乳胶粒表面的单体浓度很高，而且壳单体有充分时间渗入到种子乳胶粒子内部。间歇法：壳单体一次性加入，在引发剂存在下引发聚合，这种方法也使乳胶粒表面单体浓度很高。半连续法：将壳单体连续滴加，使种子乳胶的表面和内部壳单体浓度都很低，既聚合物处在饥渴状态.此只能在核聚合物上连续形成壳层而缺乏核壳层间的结合。10优质课Company name影响核壳乳液聚合的因素影响核壳结构的因素除
5、了两中单体的加料次序外，还与单体的亲水性有关。一般乳液聚合都以水为分散介质，亲水性较大的聚合物易和介质水接近，而疏水性倾向于排斥介质水，因而形成不同结构形态的胶乳粒子。正常结构和非正常的结构形态(如翻转形等)乳胶粒。11优质课Company name核壳乳液聚合的应用举例（1）多层特种结构聚合物乳胶粒子递变进料、单体A单体B、洋葱当R0：R1=1：2，内部富含B外部富含A的核壳聚合物；当R0R1，无规共聚物；当R0R1，典型的B核A壳聚合物12优质课LOGOLOGO 核壳乳液聚合的应用举例（2）synthesis and application of anionic acrylic（阴离子丙烯
6、酸） emulsion used as paper wet-strength additive1313Related imformationvTitlesynthesis and application of anionic acrylic emulsion（阴离子丙烯酸） used as paper wet-strength additivevAuthors Xin Liu, Chunhua Tian, Yuying Wu, Xueming ZhangCollege of Materials Science and Technology, Beijing Forestry Universit
7、y vFrom 4th International Conference on Pulping,Papermaking and Biotechnology优质课Contents1. Abstract2. Introduction3. Experienment4. Results and discussion5. Conclusion优质课Abstractvpolymerization butyl acrylate (BA) as soft monomer, styrene (St) as hard monomersodium dodecyl sulfate (SDS) and dodecyl
8、polyoxy ethylene (OP-10) as emulsifiers under nitrogen丙烯酸丁酯、苯乙烯、十二烷基硫酸钠、烷基酚聚氧乙烯醚vthe optimal conditionsthe ratio of SDS to OP-10 was 1:2, total dosage was 8%;the dosage of initiator was 0.25 g, including 0.15g in seeded polymerization process and 0.1g in shell polymerization process; the functional
9、monomer dosage was 7.5 g.优质课Abstractvused as wet strength agentsingle use of APSBM（苯乙烯-丙烯酸丁酯-甲基丙烯酸） was not goodsimultaneous use of 0.3% APSBM and 0.7% PAE showed great improvement of wet strength to 38% SEM photographs showed that the appearance of paper treated with 0.7% PAE and 0.3% APSBM had a c
10、lose crosslinking（交联）优质课Introduction background1/environmental-friendly products-MF（脲-甲醛树脂）/UF（三聚氰胺一甲醛树脂）/PAE（聚酰胺环氧氯丙烷）2/excellent penetrability（渗透性）, affinity（亲和力）, and film forming ability;it can disperse in water without organic solvent3/some disadvantages: high temperature of film forming, lower
11、 rigidity（刚度）, tending to get soft, poor water resistance（抗水性） of cured（熟化） film, ect4/One solution to solve above mentioned problemsis to develop special structure of particles called core-shell structure （核壳结构）of the polymer particles优质课Introduction idea a new concept of particle design, that is,
12、changing the structure of latex（胶乳） particles through designing the composition of core and shell structures of latex particlesas to improve the properties of emulsionacrylate copolymer（丙烯酸共聚物） emulsion with core-shell structure was prepared using styrene (St) （苯乙烯）as hard monomer and butyl acrylate
13、 (BA) （丙烯酸丁酯）as soft monomer.优质课ExperienmentA constitutional formula synthesized by St（苯乙烯）,BA（丙烯酸丁酯） and -MAA（甲基丙烯酸）优质课ExperienmentCopolymer synthesisSeed（种子聚合） emulsifier, buffer and distilled water mixed seed monomers, potassium peroxydisulfate（过硫酸钾）Core （核聚合） core monomers which were well pre-em
14、ulsifiedShell（壳聚合） well pre-emulsified shell monomers优质课ExperienmentPaper sheets preparation and analysishardwood bleached kraft pulp(HBKP)（阔叶木漂白硫酸盐浆）80 g/m2 basis weightWet tensile strength and folding enduranceEmulsion characterizationobservation of emulsions state,viscosity and color; the solid c
15、ontent, conversionmechanical stability, ionic stability, pH stability and storing stability (one month)优质课LOGOLOGOThank You!2323Results and discussion1/more than 98%2/as the amount of SDS increased, the flocculation of emulsion significantly increased and the storing stability reduced,also the emuls
16、ion began to layer.3/same charge causes the bonding of the emulsifier molecules and latex particlesto decline.优质课Results and discussionDuring seed reaction stage, when emulsifier dosage was 3%, the monomer conversion rate was the lowestof all; During core reaction stage, as the reaction went on, the
17、 monomer conversion rate increased fast,especially the emulsifier dosage 3% increased significantly; During shell reaction stage, the conversion rate increased slowly; At the end of reaction, the conversion rates of four different emulsifier dosages system were almost the same, which could allreach
18、more than 99%优质课Results and discussion1/As the amount of emulsifierincreased, the reaction began to gel and the blue fluorescence became less obvious.优质课Results and discussion1/0.00/90.49%0.10/98.87%0.15/98.56%2/it need additional initiator during shell polymerization reaction,because of theconsumption during seed and core polymerizationreactions.优质课Results and discussion1/when the amount of -MAA was2.5 g, the emulsion was transparent with a lower viscosity.2/When the dosage was between 5.0 g and 10.0 g, the conversions were higher and thestability all performed well.优质课LOGOLOGOThank You!2929
