正交试验法研究聚苯乙烯微球分散聚合法的制备

以苯乙烯为反应单体,聚乙烯吡咯烷酮为稳定剂,偶氮二异丁腈为引发剂,乙醇与水为反应介质,采用分散聚合法制备聚苯乙烯微球。实验中选取了PVP浓度、初始单体St浓度、引发剂浓度、分散介质的组成以及反应时间五个因素,每个因素选取了5个水平,设计5因素5水平正交试验表研究各因素对微球粒径变化及对微球单分散性的影响。实验结果表明,对于微球的分散性,各因素影响的大小为TimeStE/WPVPAIBN。对于微球的粒径,各因素影响的大小为E/WPVPTimeStAIBN。同时,成功制备出了平均粒径为0.851,1.133,1.257,1.366,1.747μm,单分散性好的聚苯乙烯微球。     

分散聚合法制备微米级聚苯乙烯微球

简要评述了微米级聚苯乙烯 ( PS)微球的制备方法 ,并着重介绍了用分散聚合法制备 PS微球时单体浓度、介质、稳定剂、引发剂与温度、反应时间、搅拌速度、气氛等影响因素及微米级 PS微球的应用与发展。     

微米级单分散聚苯乙烯微球的制备

以苯乙烯(St)为单体、偶氮二异丁腈(AIBN)为引发剂、聚乙烯吡咯烷酮(PVP)为分散稳定剂,在乙醇-水反应介质中,采用分散聚合法制备了微米级单分散聚苯乙烯(PS)微球。分别用电镜扫描和激光粒度仪表征了PS微球表面形貌、粒径及粒度分布,探讨了影响PS微球粒径及粒度分布的诸多因素。结果表明,AIBN用量(以单体质量计,下同)大于5.0%或PVP用量(以单体质量计,下同)小于2%时,PS粒子间有聚并现象;当St浓度为10%、AIBN用量为2.5%、PVP用量为5.5%、醇水质量比为90∶10、聚合温度为70℃时,制备的PS微球粒径为1.612μm、粒度分散系数为0.357,微球单分散性及球形度最佳。     

分散聚合法制备单分散聚苯乙烯微球

用分散聚合法,在乙醇/水介质中,以苯乙烯为单体,偶氮二异丁腈为引发剂,聚乙烯吡咯烷酮为分散剂制备了聚苯乙烯(PS)微球。探讨了制备条件对微球形貌、粒径及粒径分布的影响。结果表明,在合适条件下,可以制备粒径在1μm左右,粒径分布在1.04~1.08,表面光滑且互不粘连的单分散PS微球。     

交联型单分散聚苯乙烯微球的制备

以聚乙烯吡咯烷酮（PVP）为分散剂，偶氮二异丁腈（AIBN）为引发剂，乙醇为分散介质，二乙烯基苯（DVB）为交联剂进行了苯乙烯（St）的分散聚合；讨论了引发剂、交联剂、分散剂、单体用量对聚合物粒径及分布的影响，制备了交联型单分散聚苯乙烯微球。实验表明：当交联剂质量分数达到单体质量分数的1％时，微球依然可以保持良好的单分散性。在聚合体系中引入抗坏血酸，使其与微量的氧结合，有效地提高了微球的均匀度。     

连续法制备单分散聚苯乙烯微球及粒径影响因素的研究

以苯乙烯为单体,偶氮二异丁腈(AIBN)为引发剂,聚乙烯吡咯烷酮(PVP)为分散剂,采用连续分段添加引发剂的方法制备微米级的聚苯乙烯微球。研究了引发剂的添加方式,各组分用量变化对聚苯乙烯微球粒径和粒径分布的影响。结果表明:在反应过程中不断地补加引发剂可以保持活性自由基的生成速率,对聚苯乙烯微球的粒径和粒径分布有着重要的影响。在此基础上,通过改变各组分的用量可以制备出表面光洁,粒径在1.3μm左右的聚苯乙烯微球,且单分散性良好,单分散系数在1.02左右。     

不同聚苯乙烯微球的磺化

胶体颗粒是研究凝聚态物理性质、生命物质组装的理想模型体系,对胶体颗粒的研究具有十分重要的理论价值。聚苯乙烯(PS)微球是目前应用最为广泛的胶体粒子,由于其在合成过程中粒径可控且形貌均匀,因此,受到了越来越多的关注。文章制备了未交联的和交联的2种PS微球,研究了磺化时间对这2种PS微球的Zeta电势和粒径的影响。结果表明,在一定的反应时间内,未交联PS微球的Zeta电势和粒径,随磺化时间增加至原粒径的2.5倍,最后溶解。交联PS微球的Zeta电势和粒径随磺化时间增加至原粒径的5.5倍,但不溶解,而是形成C型胶体粒子。掌握了聚苯乙烯微球的磺化规律,可以得到尺寸及带电量不同的磺化聚苯乙烯,对凝聚态的物理性质的等研究具有重要意义。     

单分散聚合法制备微米级聚苯乙烯微球

采用分散聚合的方法,以聚乙烯吡咯烷酮为分散剂、无水乙醇为反应介质、偶氮二异丁腈为引发剂作为反应条件,成功制备出了粒径范围为1～10μm不同粒径级别的单分散(分散系数≤5%)微米级聚苯乙烯(PS)微球。并研究了用分散聚合法制备PS微球时单体浓度、介质、稳定剂、引发剂与温度、反应时间、搅拌速度、气氛等影响因素及微米级PS微球的应用与发展。     

聚苯乙烯中空微球的合成与性能研究

采用半连续乳液聚合法,以酸性乳胶粒子为核,在核表面包覆弱亲水性的中间层,然后在中间层的表面包覆强疏水的壳层,并向壳层中引入交联单体,制备出兼具溶胀能力且稳定性良好的聚合物乳胶粒子。探讨了乳化剂用量、核壳比、交联剂用量与pH值对微球形态的影响,总结出最优的工艺条件。结果表明,制备聚合物中空微球的最佳实验条件为:酸性核制备阶段乳化剂用量为0.1wt%,壳层制备阶段核壳比为0.8,交联剂用量为3-6wt%,碱溶胀阶段初始pH值为10.78。     

分散聚合法制备亚微米级单分散聚苯乙烯微球

以醇和水的混合液为分散介质,聚乙烯基吡咯烷酮（PVP）为分散剂、偶氮二异丁腈（AIBN）为引发剂,利用分散聚合法制备亚微米级的单分散聚苯乙烯（PS）微球。分别讨论分散剂的用量以及分散介质的溶解度参数对PS微球粒径的影响。结果表明,当分散介质溶解度参数和单体苯乙烯的溶解度参数越接近时,所制得的PS微球粒径越大,反之越小;随着分散剂PVP量的增加,微球的粒径减小,粒径分布变窄;所制得的聚苯乙烯微球表面光滑,呈均匀的球形。     

单分散大粒径交联聚苯乙烯微球的制备及功能化改性的研究进展

单分散的聚合物功能微球具有许多突出优点,如比表面积大、表面反应能力强等。系统地分析和综述了单分散交联聚苯乙烯功能微球的制备方法及应用的最新研究进展,并对该类功能材料的发展前景进行了预测。     

石蜡聚苯乙烯微球的制备

用悬浮聚合法制备石蜡聚苯乙烯微球。研究了合成过程中搅拌器的位置、搅拌速度、升温速度和反应时间等对微球粒径分布及其产率的影响。     

无皂乳液聚合法合成单分散性阴离子聚苯乙烯微球

采用无皂乳液聚合法制备了粒径大小可控且均一的聚苯乙烯微球,研究了反应过程中SDS加入量、反应温度、引发剂加入量及反应介质对聚苯乙烯微球粒径大小及分布的影响。利用傅立叶变换红外光谱仪对微球结构进行了表征。     

多孔聚合物微球的制备及其在化妆品中的应用进展

简要介绍了单分散多孔聚合物微球的应用,重点综述了多孔聚合物微球用作化妆品活性物载体时所起的控释和缓释作用;讨论了多孔聚合物微球的合成手段,包括悬浮聚合法、分散聚合法和种子溶胀法,种子溶胀法中的动态溶胀法和二步溶胀法更易得到粒径均一的多孔聚合物微球;同时介绍了其成孔机理和性能表征;最后提出了多孔聚合物合成以及在化妆品应用中目前存在的问题、发展方向和应用前景。     

The influence of water on size of the monodisperse polystyrene microspheres prepared by dispersion polymerization

Polystyrene microspheres with uniform sizes have a wide range of applications in biomedical engineering. However, detailed and systematic investigations on the influence of water content on alcohol/water systems are relatively scarce. In this study, the impact of trace water content on microsphere size was comprehensively examined, and a systematic exploration of the varying effects of different hydration levels on particle nucleation and growth mechanisms was conducted. When the water content increased from 0.1% to 0.4%, the microsphere diameter rapidly decreases from 3.6 to 2.71 μm. Correspondingly, the molecular weight increased from 29,797 to 69,186. However, within the water content range of 0.5%–14.5%, alterations in water content induced only slight variations in the microsphere diameter. The microsphere size, molecular weight, conversion rate, and reaction rate were compared in two stages. It was observed that the diminishing influence of water on the system was due to the changes in the main polymerization sites. Subsequently, the addition of water content up to 33.5% revealed an exponential decrease in the microsphere size with increasing water content in ethanol. This pattern was also observed in methanol and isopropanol, demonstrating its universality and predictability, making it applicable for precise prediction of microsphere size in different solvents.     

水性含氟丙烯酸酯共聚物的疏水性研究

以脂肪醇聚氧乙烯醚/十二烷基硫酸钠/阴离子含氟乳化剂(AEO/SDS/FSA)为复合乳化剂体系,以甲基丙烯酸十二氟庚酯(FMA)、丙烯酸丁酯和甲基丙烯酸甲酯等原料合成了稳定的水性含氟丙烯酸酯共聚物(PFA)。考察了FSA用量对聚合反应稳定性的影响,并研究了FMA用量和FSA用量等因素对PFA疏水性的影响规律。     

Preparation of core–shell poly(acrylic acid)/polystyrene/SiO2 hybrid microspheres

Core–shell poly(acrylic acid)/polystyrene/SiO₂ (PAA/PS/SiO₂) hybrid microspheres were prepared by dispersion polymerization with three stages in ethanol and ethyl acetate mixture medium. Using vinyltriethoxysilane (VTEOS) as silane agent, functional silica particles structured vinyl groups on surfaces were prepared by hydrolysis and polycondensation of tetraethoxysilane and VTEOS in core stage. Then, the silica particles were used as seeds to copolymerize with styrene and acrylic acid sequentially in shell stage I and stage II to form PAA/PS/SiO₂ hybrid microspheres. Transmission electron microscope results show that most PAA/PS/SiO₂ hybrid microspheres are about 40 nm in diameter, and the silica cores are about 15 nm in diameter, which covered with a layer of PS about 7.5‐nm thick and a layer of PAA about 5‐nm thick. This core–shell structure is also conformed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and differential scanning calorimetry. FTIR results show that silica core, PS shell, and PAA outermost shell are bonded by covalents. In the core–shell PAA/PS/SiO₂ hybrid microsphere, the silica core is rigidity, and the PAA outermost shell is polarity, while the PS layer may work as lubricant owning to its superior processing rheological property in polymer blending. These core–shell PAA/PS/SiO₂ hybrid microspheres have potential as new materials for polar polymer modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1729–1733, 2006     

双尾型丙烯酰胺类疏水缔合共聚物的合成与表征

通过光引发自由基聚合的方式,将双尾型丙烯酰胺类疏水单体(N-苯乙基-N-十四烷基甲基丙烯酰胺,PETMAM),与丙烯酰胺(AM)、丙烯酸(AA)等水溶性单体进行共聚,制备出双尾型疏水缔合水溶性共聚物(DTHAP),来解决丙烯酰胺类聚合物耐温抗盐性以及稳定性差的难题。通过测定聚合物溶液的表观黏度作为评价其性能的主要手段,考察了丙烯酸加量、盐、表面活性剂(SDS)含量、疏水单体含量等因素对聚合物性能的影响,从而确定了比较理想的反应条件。实验中发现:丙烯酸加量和表面活性剂含量的变化会影响聚合物的临界缔合行为;盐的引入能够显著降低表面活性剂的用量,提高聚合物的增黏效果;疏水单体含量较低时[0.35%～0.45%(mol)],聚合物可以表现出明显的增黏效果。当聚合物浓度为1 g·L^-1时,聚合物的黏度可以达到141.5 mPa·s,其临界缔合浓度(CAC)为0.75 g·L^-1左右。聚合物在120 g·L^-1的NaCl溶液和120 g·L^-1 NaCl、0.4 g·L^-1 CaCl₂溶液中,80℃下老化90 d,黏度分别为47.6 mPa·s和45.9 mPa·s。采用红外光谱、扫描电镜两种手段,表征了聚合物的结构。     

Preparation and properties of magnetic polystyrene microspheres

Magnetic polystyrene nanospheres were efficiently prepared by using a new indirect process based on miniemulsion polymerization of styrene. The samples were characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), and vibrating‐sample magnetometry (VSM), respectively. The experimental results clearly show that the 3‐methacryloxypropyltrimethoxy silane was anchored onto the surface of the magnetic particles to form the vinyl end. The size of the magnetic particle is about 6–30 nm. The size of the magnetic particle capped with polystyrene is about 1–2 μm. The magnetic polystyrene spheres exhibit multidomain character, whereas the pure magnetic particles show single domain character. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3660–3666, 2007