粘度调节剂对制备环氧树脂微球的影响

研究粘度调节剂对环氧树脂/二氨基二苯基砜/聚醚酰亚胺(EP/DDS/PEI)共混物相结构及制备EP微球的影响。结果表明,共混物中加入粘度调节剂后,固化过程中共混体系的粘度明显降低,随着粘度调节剂用量的增加,EP分散相尺寸逐渐增大,制得的EP微球粒径及粒径分布指数逐渐增大。EP微球的红外光谱显示粘度调节剂对EP微球的成分和相结构没有明显影响。     

MeTHPA/THPA用量比对环氧树脂微球制备的影响

考察甲基四氢苯酐(MeTHPA)/四氢苯酐(THPA)用量比对环氧树脂/MeTHPA/THPA/聚酯共混体系固化物相结构以及环氧树脂微球的影响。结果表明,随着MeTHPA/THPA用量比的增加,环氧树脂/MeTHPA/THPA/聚酯共混体系固化物的环氧树脂分散相尺寸逐渐减小,制得的环氧树脂微球的粒径及其单分散性指数逐渐降低。当使用纯MeTHPA时,制得的环氧树脂微球粒径约为4μm,单分能胜指数为1.155 3。     

BMI/DBA/PC改性树脂体系的制备与性能研究

采用熔融预聚法制备N, N'-4, 4' -二苯甲烷双马来酰亚胺（BMI）/二烯丙基双酚A(DBA)/聚碳酸酯（PC） (BMI/DBA/PC) 改性树脂体系,研究了含有不同含量PC的改性树脂的力学性能、热稳定性及界面结构。结果表明,PC的加入能明显提高树脂的韧性和强度;当PC含量为8 %（质量分数,下同）时,相比BMI/DBA树脂浇铸体,BMI/DBA/PC树脂浇铸体的拉伸强度提高36.3 %,冲击强度提高109.1 %;改性树脂体系保持了优异的热稳定性和较高的热变形温度;改性树脂体系的相界面结构为PC相以微球状分散于BMI/DBA中,相界面较厚,界面作用较好。     

双马来酰亚胺树脂微球的制备

合成了1种新型的聚醚酰亚胺(PEI-A)。将PEI-A与双马来酰亚胺树脂(BMI)和二烯丙基双酚A(DBA)体系共混,经反应诱导相分离,制备了3～5μmBMI树脂微球。     

聚醚酰亚胺／环氧树脂共混物的相结构及制备环氧树脂微球的研究

采用共缩聚方法合成了一种新型聚醚酰亚胺（COPEI），通过改变它在COPEI／双酚A二缩水甘油醚型环氧树脂（E828）／二氨基二苯基砜（DDS）共混体系中的用量，考察了对共混体系的相结构以及对制备环氧树脂微球的影响。研究结果表明：加入COPEI树脂后，共混体系发生相分离，得到不同的相结构。当COPEI树脂含量在30％（质量）以上时，共混体系出现完全反转相结构，随着其含量增加，环氧树脂分散相尺寸逐渐减小，制得的环氧树脂微球粒径和粒度分布逐渐降低。红外光谱显示环氧树脂微球间的特征吸收峰以及与纯环氧树脂的特征吸收峰问都没有明显区别。DSC分析显示环氧树脂微球的玻璃化温度（Tg）略低于纯环氧树脂的Tg，而且随着COPEI用量增加，环氧树脂微球的Tg有降低的趋势。     

单分散性PLGA磁性微球的制备及其缓释性

为获得单分散性PLGA磁性微球,以纳米四氧化三铁明胶分散液作为内水相(W1),PLGA(聚乳酸羟基乙酸共聚物)的二氯甲烷溶液作为油相(O),PVA(聚乙烯醇)水溶液作为外水相(W2),利用T型微通道并采用复合乳液法制备PLGA磁性微球,考察油相(O)质量浓度、外水相(W2)质量分数、流速比及油相与内水相体积比对微球制备的影响。借助FTIR、SEM、光学显微镜及VSM(振动样品磁强计)对磁性微球组分、形貌、粒径分布和磁学性能进行表征;并以阿司匹林作为药物模型进行缓释性测试。结果表明:油相中PLGA质量浓度为0.050kg/L,外水相(W2)中PVA质量分数为1%及2%,流速比v(W2)∶v(W1/O)=120∶1且体积比V(O)∶V(W1)=2∶1时可均匀成球,其粒径分布系数CV值仅为4.66%,表现出良好的单分散性;此时,比饱和磁化强度可达1.52emu/g,兼具优异顺磁性。制得的载药微球在60 h内表现出阶段性匀速释放,且有较好的磁响应性,有望用于磁响应性药物载体。     

聚氨酯/丙烯酸酯热膨胀微球的制备与性能研究

以聚四氢呋喃二元醇(PTMG-300)为软段,甲苯二异氰酸酯(TDI)为硬段,丙烯酸羟乙酯为封端剂,制得端基为双键的线性聚氨酯齐聚物。将质量分数为9%的端双键聚氨酯与丙烯酸酯单体共混后加入发泡剂正己烷、引发剂(AIBN),在Mg(OH)_2/聚乙烯吡咯烷酮(PVP-K30)复合分散剂作用下乳化分散20 min,经自由基聚合制得粒径10~30μm,起始发泡温度90℃,稳泡温程57℃,发泡倍率6倍的热膨胀微球。研究了复合分散剂、二异氰酸酯结构、二元醇结构和聚氨酯用量对热膨胀微球粒径分布和发泡性能的影响。     

聚苯乙烯/聚酯共混微球的制备及性能

采用相反转乳化工艺制备了亚微米级聚苯乙烯/聚酯共混微球。分析了制备机理、微球中聚酯与聚苯乙烯的相容性及微球形貌,讨论了聚酯用量对微球粒径及分布的影响,测试了共混微球的抗冲击性能、软化温度、附着性以及熔体流动性能。结果表明:微球中聚酯与聚苯乙烯构成不相容体系;共混微球表面粗糙;微球粒径及分布随聚酯用量变化显著,当聚酯质量分数约为14%、乳化剂用量为11%时[乳化剂用量为乳化剂与单体相(苯乙烯和聚酯)质量比],可以得到平均粒径365.3 nm、分散性系数为0.101的亚微米级共混微球;当聚酯质量分数为12%～18%时,随着聚酯含量的增加,共混微球的冲击强度、附着力显著增加,但熔体流动速率降低。     

单分散多孔聚合物微球的制备及其反相色谱应用

用分散聚合的方法制得单分散微米级聚苯乙烯微球(PS),以此聚苯乙烯微球作为种子,以邻苯二甲酸二丁酯为溶胀剂,苯乙烯为单体,二乙烯基苯为交联剂,甲苯为致孔剂,采用种子溶胀聚合的方法制得粒径分布较窄的多孔高交联的聚苯乙烯-二乙烯基苯微球(PS-DVB)。研究了交联剂与致孔剂的加入量对微球形貌、粒径及孔结构参数的影响。结果表明,所得多孔微球球形圆整,库尔特测得平均粒径为5.067~5.520μm,粒径分布窄,D90/D10为1.23~1.56,孔结构可控,并以此多孔微球作为反相色谱填料基质,理论塔板数每米可达6 000~15 000,可以用作高效液相色谱(HPLC)填料。     

糠醛渣木质素/聚乙烯亚胺微球的制备

木质素和聚乙烯亚胺（PEI）对重金属离子有良好的亲和力,且木质素来源广泛、具有良好的生物降解性能,在水处理方面有很好的前景。本文以糠醛渣木质素和聚乙烯亚胺为主要原料,十二烷基苯磺酸钠（SDBS）为分散剂,环氧氯丙烷（EPI）为交联剂,液体石蜡为油相,采用反相悬浮聚合法,制备了糠醛渣木质素/PEI微球（LMS）。通过FTIR、XRD、SEM和激光粒度仪对微球的结构和形貌进行表征,研究了木质素用量、PEI用量、EPI用量、SDBS用量、油水比和反应温度对木质素微球制备的影响。结果显示,在木质素用量为0.600g,PEI用量为2.25g,EPI用量为2.25mL,SDBS用量为0.075g,温度为56℃,油水体积比为4.5∶1的条件下,制得的糠醛渣木质素/PEI微球平均粒径为135μm,粒径分散度为0.290,比表面积为46.5m²/g,球型度良好,球体表面有少量微孔。     

聚醚酰亚胺/环氧树脂体系的固化及相分离行为研究

环氧树脂固化物本征的低韧性是限制其在复合材料应用的主要缺点之一。利用高性能热塑性树脂聚醚酰亚胺(PEI)与环氧树脂共混,系统研究了PEI在环氧树脂中的溶解行为、固化行为以及相分离行为。溶解试验表明:PEI与环氧齐聚物具有良好的相互溶解性;同时,PEI的加入降低了环氧树脂固化反应的活化能,但并没有改变其固化反应的机制。扫描电镜结果显示:随着PEI含量的增加,环氧/PEI浇铸体的相形貌从明显的分散颗粒相结构演变为双连续相结构和反转相结构。     

Poly(ether imide)‐modified benzoxazine blends: Influences of phase separation and hydrogen bonding interactions on the curing reaction

Polymer blends of polybenzoxazine (PBZ)/poly(ether imide) (PEI) were prepared by the in situ curing reaction of benzoxazine (BZ) resin in the presence of PEI. Phase separation induced by the polymerization of BZ resin was observed. The rheological behaviors, morphologies, and their evolution process of BZ/PEI blends were investigated by rheometer and scanning electron microscope. Phase separation that took place at the early stage of the curing reaction effectively reduced the dilution effect of PEI. Fourier transform infrared (FTIR) results suggested that hydrogen bonds between PBZ and PEI existed during the whole curing process, although weakened with phase separation. The decrease of isoconversion activation energy indicated that the polymerization of BZ resin was facilitated in the presence of such kind of hydrogen‐bonding interactions. By changing the weight fraction of PEI, extensive phase separation was obtained in PBZ blends with 5 and 20 wt % of PEI, in which systems, the crosslinking density and glass transition temperature (T_g) of PBZ‐rich phase were greatly improved compared to this single PBZ system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Bismaleimide‐modified methyl‐di(phenylethynyl)silane blends and composites: Cure characteristics,thermal stability,and mechanical property

Reactive blends of organic‐inorganic hybrid monomer, methyl‐di(phenylethynyl)silane (MDPES) and a modified bismaleimide resin (BMI/DBA) have been prepared. The thermal and oxidative stabilities of MDPES‐BMI/DBA blends were characterized by thermogravimetric analysis, derivative thermogravimetry, differential thermal analysis, dynamic mechanical analysis, and flexural strength retention at 240°C. Scanning electron microscopy was employed to study the surface morphology of MDPES‐BMI/DBA composite after thermal oxidative treatment. With the increase of concentration of BMI/DBA, flexural strength of composites increased from 78 to 331 MPa. The results showed that MDPES‐BMI/DBA blends exhibited excellent thermal and thermal oxidative properties, and the interface between MDPES and glass fiber was improved by the incorporation of BMI/DBA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Thermal properties and morphology of blends of poly(ether imide) and polycarbonate

Blends of poly(ether imide) (PEI) and bisphenol-A polycarbonate (PC) have been investigated by differential scanning calorimetry, dynamic mechanical thermal analyzer, scanning electron microscopy, and transmission electron microscopy. Three different molecular weights of polycarbonate have been used in the PEI-PC blends. Blends were prepared by screw extrusion and solution casting with weight fractions of PEI in the blends varying from 0.90 to 0.10. From the measured glass transition temperature (T_g), the maximum decrease of T_g(PEI) is observed for 0.9 weight fraction PEI in the PEI-PC blends. In the study of the morphology, the size of minor component domains (about 0.1 to 0.3 µm) in the 90/10 PEI-PC blend is small compared to the size of minor component domains (about 0.2 to 2.0 µm) in the 10/90 PEI-PC blend. This morphological behavior is attributed mainly to the difference of viscosity ratio between the dispersed phase and continuous phase. No considerable differences in the thermal behavior and morphologies have been observed among the blends of PEI and PC having different molecular weights.     

Effects of processing conditions on foaming behaviors of polyetherimide (PEI) and PEI/polypropylene blends in microcellular injection molding process

Foaming behaviors of both neat polyetherimide (PEI) and PEI/polypropylene (PP) blends were studied in this article in microcellular injection molding (Mucell) process. The study mainly focused on the comparison of two materials' foaming behaviors under different processing conditions which took a critical effect on the morphologies of foams. The results indicated that the different characteristics of PEI and PEI/PP blends, such as melt strength, gas dissolvability, and solubility, induced different nucleation ability of PEI and PEI/PP blends. The addition of PP could obviously improve the cell density and reduce the cell size. With the processing conditions changing, the morphologies of PEI/PP altered more variously, and their distribution of cell density was wider. This suggested that foaming behaviors of PEI/PP blends was more flexible to be controlled by the processing conditions than neat PEI. The effects of shot size, gas injection, and injection rate on foam morphologies were studied in detail. Shot size determined the weight reduction of samples and affected the cell density and size significantly. Gas dosing time and dosing rate determined the gas ratio which effected on foam morphologies of the PEI and PEI/PP foams. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41443.     

聚醚酰亚胺对炭黑填充环氧树脂复合材料导电性能和吸波性能的影响

利用反应诱导方法设计制备了炭黑(CB)包覆环氧树脂(EP)微球/聚醚酰亚胺(PEI)(EP/PEI/CB)复合材料。研究了该复合材料的微观结构,测量了其导电性能及在Ka波段的吸波性能,并与CB填充EP(EP/CB)复合材料进行了对比。结果表明,在EP/PEI/CB中,CB选择性分布在PEI相中并形成较规则的立体网状连续相,EP为30μm左右大小的微球分散相,与EP/CB相比具有更低的体积电阻率。EP/PEI/CB属于一种谐振腔式吸波体,在33～40 GHz范围具有较好的吸波性能且优于EP/CB,最大吸收峰出现在35.61 GHz,峰值反射率(R)为–17.40 dB,吸收带宽3.22 GHz(R–10 dB).     

热塑／热固共混树脂对复合材料抗冲击损伤性能的影响

碳纤维／热固性树脂复合材料层合板的抗冲击性能着。本文利用溶液法共混制备聚醚酰亚胺／双马亚酰亚胺烯丙烯丙基共聚物的共混树脂体系实施增韧。