大滞后可逆热致变色微胶囊的制备及性能研究

以结晶紫内酯(CVL)、双酚A(BPA)、2-(4-苄基氧基苯基)乙基癸酸酯(DAE)为芯材,以三聚氰胺-尿素-甲醛共聚树脂为壁材,以苯乙烯-马来酸酐共聚树脂(SMA)为乳化剂,制备了大滞后可逆热致变色微胶囊,并采用纳米粒度仪对微胶囊的大小进行了表征,同时采用DSC技术对微胶囊的热致变色机理进行了研究,并探讨了变色温度...     

溶剂挥发法制备噻唑磷微胶囊

制备基于聚乳酸(PLA)改性聚丁二酸丁二醇酯(PBS)为载体的噻唑磷微胶囊。采用溶剂挥发法以聚乙烯醇-1788为乳化分散剂制备微胶囊,通过激光粒度分析仪、光学显微镜、扫描电镜对微胶囊进行形貌表征,用紫外分光光度计研究微胶囊的缓释行为。经聚乳酸(PLA)共混改性后的PBS载体微胶囊的包封率为85.27%、载药量为61.64%,平均粒径为5.46μm,缓释期为30 d。改性后的微胶囊具有较好的形貌,载药量和包封率比纯PBS载体微胶囊高,药物缓释更长。     

界面聚合法聚氨酯微胶囊相变材料性能研究

本文以硬脂丁酸酯为芯材,苯乙烯-马来酸酐共聚物(SMA)为乳化剂,单体甲苯2,4-二异氰酸酯(TDI)、异佛尔酮二异氰酸酯(IPDI)、多醚聚元醇(分子量为500和1 000)为反应性单体,采用界面聚合制备微聚氨酯壳体微胶囊相变材料。通过光学显微镜、称重法对所制备微胶囊的表面形貌、热稳定性和化学结构作了表征和分析。将相变材料微胶囊通过浸轧法整理于织物的表面,实现纺织品蓄热调温功能。通过光学显微镜、热温度计法对所制备微胶囊的表面形貌、整理织物效果进行测试。实验结果表明:TDI和多醚聚元醇(分子量为500)为单体制备的微胶囊的稳定性、整理到织物上的效果明显较好;同一反应单体在不同温度下制备的微胶囊效果也有巨大的差异,太高的温度和过低的温度所制备的微胶囊的效果都不好。     

聚苯乙烯接枝包覆硫黄微胶囊的制备与表征

以合成硫黄为芯材、聚苯乙烯(PS)为壳材,采用原位接枝改性聚合方法制备PS接枝包覆硫黄微胶囊,分析不同苯乙烯/硫黄颗粒配比对硫黄微胶囊形貌的影响,表征接枝状况和热稳定性。结果表明,当硫黄颗粒用量不变、苯乙烯用量为1.5 mL时,硫黄微胶囊的表面形貌规整,分散性较好,热稳定性提高。     

聚苯乙烯接枝包覆硫磺微胶囊的制备与表征

以合成硫磺为芯材,聚苯乙烯为壳材,采用原位接枝改性聚合方法制备了聚苯乙烯接枝包覆硫磺微胶囊,研究了不同苯乙烯/硫磺颗粒配比对微胶囊形貌的影响,制备了粒径均一分布的硫磺微胶囊,且分散均匀。结果表明苯乙烯的含量对微胶囊的表面形貌有很大影响,经包覆之后硫磺微胶囊的热稳定性提高。     

脲-甲醛预聚体的制备对玫瑰香精微胶囊化的影响

以脲醛树脂为囊壁的玫瑰香精微胶囊,其囊壁原料脲-甲醛预聚体的制备,采用了碱催化下的加成反应工艺。研究了脲甲醛量比、反应介质的pH值、催化剂、加成反应温度对微胶囊粒径、包埋率及表面结构的影响。优化的加成反应条件为:脲甲醛量比为n(脲)∶n(甲醛)=1∶2.0,以氢氧化钠为碱性催化剂,反应pH=8.0,反应温度70°C,反应时间1h。     

脲甲醛预聚合对酞菁绿G颜料微胶囊化的影响

从脲、甲醛的预聚反应条件入手，讨论了脲甲醛量比、反应介质的pH值、催化剂和反应温度对酞菁绿G颜料微胶囊化过程以及微胶囊结构、表面形态、粒径及其分布和包埋率的影响。实验结果表明，当脲甲醛量比为n(脲)：n(甲醛)=1：2.0，以氢氧化钠为碱性催化剂，反应介质pH值=8．0，反应温度70℃，反应时间1小时。得到的脲-甲醛预聚物水溶性好，用原位聚合法制备微胶囊时可以避免发生微胶囊表面形态呈非球形、凹陷和开裂。在以上条件下，制得了包覆结构紧密、包埋率较高、粒径分布均匀且平均粒径为3．2μm的球形固体微胶囊。     

Uron环改性SBS胶粘剂的研制与应用

以尿素与甲醛通过环化反应生成Uron环衍生物,Uron环衍生物与一定比例的SBS(802型)胶粘剂、SBS(796 S/B-20/80型)胶粘剂共同制备成Uron环改性SBS胶粘剂。探讨了pH对尿素与甲醛树脂化和成环化的条件影响,并对该胶粘剂进行FT-IR、DSC、光学显微镜图片分析、力学性能测试及应用情况分析。实验结果表明:以Uron环为改性基团,对SBS型复合胶粘剂进行共混改性可有效提升产品性能。     

乳化剂对乙草胺微胶囊悬浮剂形成的影响

研究了不同类型乳化剂及其用量对乙草胺微胶囊成囊性能的影响.通过光学摄影显微镜、激光粒度仪对微胶囊表面形貌、粒径大小及其分布进行了表征.结果表明:采用苯乙烯马来酸酐共聚物(SMA)作为乳化剂,当用量3%时能够得到囊形较好的乙草胺微胶囊.二甲苯的加入有利于微胶囊的形成.     

MUF/石蜡相变储能材料的制备及其表征

以液体石蜡为囊芯材料,三聚氰胺尿素甲醛树脂(MUF)为囊壁材料,采用原位聚合法制备MUF/石蜡微胶囊,探讨了反应温度和搅拌速度对MUF/石蜡微胶囊的影响。随着反应温度增高,微胶囊囊壁厚度增大,调节微胶囊搅拌速度可以控制微胶囊粒径。采用光学显微镜观察了微胶囊的形成过程,采用扫描电子显微镜和红外光谱表征了微胶囊表面形貌与化学结构,采用DSC分析其储热性能特征,结果表明MUF/石蜡微胶囊强度好,封闭性能好,储能性能好,可以作为相变储能材料进行应用研究。     

Self-healing performance assessment of epoxy resin and amine hardener encapsulated polymethyl methacrylate microcapsules reinforced epoxy composite

In order to study the effect of healing materials viscosity on the self-healing performance of polymer composite, mostly available epoxy resin of viscosity 10–12 Pa.s and amine hardener of viscosity 0.01–0.02 Pa.s were chosen as two different healing materials and successfully encapsulated. Effect of core to shell(c/s) ratio on the synthesis of epoxy microcapsules was investigated and 1:1 c/s ratio is suggested as an ideal ratio to synthesize epoxy capsules. Chemical structure and thermal decomposition patterns of both microcapsules and capsules reinforced composite were analyzed. Tensile strength, impact strength and fracture toughness of capsules reinforced self-healing epoxy composite were evaluated. It was observed that the toughness of epoxy composite increased with the increase in microcapsules concentration. An optimum healing efficiency of 66% was observed with the addition of 7.5 wt% epoxy and hardener microcapsules at equal weight ratio. Stresses developed in the pure epoxy composite crack front were analyzed using Ansys V18.1.     

Effect of microcapsule size on the performance of self-healing polymers

The influence of microcapsule diameter and crack size on the performance of self-healing materials is investigated. These epoxy-based materials contain embedded Grubbs' catalyst particles and microencapsulated dicyclopentadiene (DCPD). Autonomic repair is triggered by rupture of the microcapsules in response to damage, followed by release of DCPD into the crack plane where it mixes with the catalyst and polymerizes. The amount of liquid that microcapsules deliver to a crack face is shown to scale linearly with microcapsule diameter for a given weight fraction of capsules. In addition, self-healing performance reaches maximum levels only when sufficient healing agent is available to entirely fill the crack. Based on these relationships, the size and weight fraction of microcapsules can be rationally chosen to give optimal healing of a predetermined crack size. By using this strategy, self-healing is demonstrated with smaller microcapsules and with lower weight fractions of microcapsules than have been possible in previous self-healing systems.     

油田堵漏剂微胶囊技术的研究

由于高吸水性固体颗粒吸水后体积会增加几十倍乃至更大,所以以它为芯材制备微胶囊有一定的难度。本实验就是以高吸水性固体颗粒为芯材,选择合适的壁材来制备微胶囊。实验以流化床喷涂法(现今已被广泛应用)制备油田堵漏剂微胶囊,结果证实了壁材的可适用性。此外还探讨了壁材的流量、压缩空气的流量、喷嘴高度及颗粒大小对微胶囊壁厚及表面形态的影响。确定了微胶囊制备的最佳工艺条件为:壁材流量Q=122mLh-1,压缩空气流量q=0.76m3h-1,喷嘴高度H=11.5cm,芯材粒径为dP=0.454mm,在此条件下的最佳壁厚度为:190~200mm。     

基于六官能度异氰酸酯用于自修复防腐涂料的微胶囊的制备与表征

微胶囊自修复技术是将自修复微胶囊埋植于基体,在破坏后实现自我修复。IPDI作为低官能度异氰酸酯在湿气中固化修复能力有限,本文设计基于六官能度异氰酸酯DiPE-IPDI/DiPE-TDI合成用于自修复防腐涂料的新型微胶囊,着重对六官能度异氰酸酯DiPE-IPDI合成过程中溶剂、温度进行反应条件优化,通过傅里叶红外光谱、核磁等对产物结构进行表征。同时对微胶囊制备过程中粒径结构进行可控组装, 通过TGA/DSC表征该自修复微胶囊热力学性能。制备负载微胶囊的自修复环氧树脂基防腐涂料,盐雾试验结果显示其具有优异的自修复性能。     

聚氨酯微胶囊的应用研究进展

聚氨酯的微胶囊化制备工艺因其有别于常规聚氨酯材料的制备工艺,所得材料的性能也更具其自身特色,同时因为芯材的存在赋予了聚氨酯材料新的功能,大幅度扩展了聚氨酯材料的应用范围。本文介绍了聚氨酯微胶囊的制备及其在建筑、纺织、医药、农业等方面的应用。     

聚四氟乙烯表面改性及粘接简

分析了聚四氟乙烯难粘的原因，综述了PTFE表面的化学改性法、高能辐射接枝法、高温熔融法、ArF激光辐射改性、离子柬注入改性法和等离子体处理法，介绍了常用表面改性剂和几种新型胶粘剂。展望了解决聚四氟乙烯材料粘接难题的研发方向。     

The effect of synthesis condition on physical properties of epoxy‐containing microcapsules

The physical properties of microcapsules are largely influenced by the synthesis conditions such as weight ratio of core/shell material, agitation rate, reaction time, and different emulsifier. Different synthesis condition would lead to different property. It is an important issue for application in composites that require self‐healing microcapsules possessing rough surface morphology, less adhesion, less core material permeability, appropriate diameter and core content, and adequate shell thickness. The properties of microcapsules influenced by the synthesis conditions were investigated systematically in this article. According to orthographic factorial design, the most influencing factor on microcapsule's yield, core material, average shell thickness and average diameter, are concluded, respectively. The synthesis parameters when the epoxy‐containing microcapsules exhibit the optimum properties are concluded: 1.4 : 1 for the weight ratio of core/shell material, 250 rpm for the agitation rate, 3 h for the reaction time and 1.5% content for the emulsifier DBS. The chemical structure of resultant microcapsules is confirmed by FT‐IR, and core material of microcapsule exhibits reactivity through DSC measurement. Subsequently, the microcapsules are characterized by SEM, OM, and contact angle experiment so as to provide parameters of microcapsule's physical properties for making binary self‐healing materials. As a result, the resultant microcapsules are suitable for fabricating self‐healing materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

吸水性微胶囊界面修饰提高水泥基材料抗渗性研究

在自修复水泥基材料中,微胶囊与水泥基体间的界面结合决定着微胶囊被裂缝触发的概率,从而影响自修复效果。本文针对吸水性微胶囊的界面结合问题,利用硅烷偶联剂KH550修饰环氧/海藻酸钙微胶囊表面,以改善其与水泥基体间的界面结合情况。采用X射线光电子能谱仪、电感耦合等离子体发射光谱仪等表征硅烷偶联剂在微胶囊表面的键合状况,利用压汞法分析水泥基材料的孔结构,并测试水泥基材料的抗渗性与自修复效果。结果表明,硅烷偶联剂能够与微胶囊外壁的海藻酸钙发生化学键合,微胶囊与水泥基体间的界面结合得到有效改善,水泥基体中有害孔数量减少,无害孔和少害孔数量增加,水泥基材料的抗渗性和自修复效果获得提升。     

Potential use of microcapsules in manufacture of fibrous products: A review

The present survey shows that microcapsules are used as effective tools for modification and functionalization of fibrous products. The core and shell materials of microcapsules can comprise various active ingredients in accordance with different requirements of final fibrous products. In this survey, the morphology, functional properties and added values of microcapsules, also such advanced types as nanocapsules, bi-, multifunctional microcapsules, and their applications in smart and other modern products are described. Some relevant applications of microcapsules in industrial processes are briefly discussed. The techniques used to encapsulate the core ingredients are also overviewed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47066.     

Tuning alginate-bentonite microcapsule size and structure for the regulated release of P. putida Rs-198

In this study, different sizes of microcapsules with alginate and bentonite as natural macromolecular materials were prepared to investigate the release property of Pseudomonas putida Rs-198. The characteristics of three microcapsules were evaluated by SEM, FTIR, TG-DSC, XRD and wall thickness. The sizes of three microcapsules (MA, MB, and MC) were 1270.50, 831.79 and 42.52?μm, respectively. First, the encapsulation efficiency of three MA, MB, and MC microcapsules were 82.20%, 90.41%, and 85.84%, respectively. Second, the contact angles of MA and MB samples were similar, while smaller microcapsules MC have higher contact angle (85.05°), indicating poor hydrophilia and decreasing the swelling degrees. Third, the release cumulant of Rs-198 and macromolecule BSA linear stage was fitted to self-established mathematic model. Results show that the microcapsule size had a considerably positive effect on release detail. The large microcapsule possessed strong leak-tightness for Rs-198 as a slow-release microbial agent. Furthermore, the porosity of microcapsules determined their swelling and release and may affect bacterial growth and survival. In conclusion, the Rs-198 microcapsule with different sizes will be pertinently selected based on the characteristics of agricultural production requirements.