聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子的制备及性能

由种子乳液聚合法制备了聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子。以过硫酸钾（KPS）为引发剂，分别以非离子型辛基酚聚氧乙烯醚（OP—10）和复合十二烷基硫酸钠（SDS）／OP—10（质量比为1：4）为乳化剂，合成了聚苯乙烯种子核。连续滴加甲基丙烯酸甲酯（MMA），以OP—10乳化的种子乳液可以制备粒径范围在0．16～0．67μm的核-壳粒子，当单体苯乙烯与甲基丙烯酸甲酯（St／MMA）的质量比为3：7时，所得粒径为0．18μm，粒径分散系数为0．012。而以OP-10／SDS质量比为4：1制备的种子乳液所得核壳粒子直径在毫米级。差示扫描量热研究显示，以OP-10乳化所得种子乳液制衢的复合粒子的玻璃化转变温度为97．2℃，峰形单一，表现山良好的热性能。     

含磷氮丙烯酸酯核壳粒子的制备

以苯基膦酰二氯、丙烯酸-β-羟乙酯和二乙胺为原料,合成了含磷氮丙烯酸酯(APEEA)功能单体。以APEEA和丙烯酸丁酯(BA)为内核材料、甲基丙烯酸甲酯(MMA)为壳层材料,通过种子乳液聚合法制备了含磷氮丙烯酸酯核壳粒子[poly(APEEA-co-BA-co-MMA)]。采用激光粒度仪(LPS)、扫描电子显微镜(SEM)、透射电镜(TEM)、热重分析(TG)和微型燃烧量热仪(MCC)对所得的样品进行了表征。结果表明:poly(APEEA-co-BAco-MMA)平均粒径在0.08~0.10μm,具有明显的核壳结构,核壳的尺寸约100 nm。当poly(APEEA-co-BA-coMMA)粒子中APEEA质量分数为15%时,分解5%的初始分解温度(Td5%)可达277℃;500℃时残炭量为5.8%,是poly(BA-co-MMA)粒子的3.87倍。质量分数15%的APEEA的引入可以使粒子的热释放率峰值降幅达55%,表明APEEA具有明显的凝聚相阻燃作用,可通过催化粒子成炭改善其燃烧性质。     

Preparation and Characterization of Soap-free Cationic Fluorinated Poly-styrene-acrylate Latex with Core-shell Structure

Soap-free cationic fluorinated Poly-styrene-acrylate latex particles with core-shell structure were synthesized by seeded semi-continues emulsion polymerization in the presence of water soluble cationic monomer Methacryloxyethyltrimethyl ammonium chloride (MADAC) and using ethanol as co-solvent. The effects of MADAC dosage and ethanol content on the stability of polymerization process and the properties of the latex particles were studied. The chemical component of the polymer was analyzed by Fourier transform infrared (FTIR). The surface element composition of the prepared copolymer film was analyzed by X-ray photoelectron spectroscopy (XPS), the micro-structure of the prepared latex particles were observed by transmission electron microscopy (TEM). The result shows that cationic soap-free fluorinated poly-styrene-acrylate emulsion with a core-shell structure can be prepared when monomer DAMAC is 6.0 wt% and ethanol is 7.5 wt%.     

聚苯乙烯/聚丙烯酸酯核壳粒子形态的研究

在简化及限制的实验条件下,利用界面张力的简化推算方法,通过调和平均法和几何平均法计算了苯丙体系复合乳胶粒子的界面张力,进而得到不同粒子形态的界面自由能变化值。根据自由能变化最小的判据推测了苯丙乳液粒子的热力学平衡形态。并采用种子半连续乳液聚合法制备了聚苯乙烯/聚丙烯酸酯核壳复合乳胶,利用透射电镜和激光粒度仪对粒子的最终核壳形态进行了证实。     

Multi-Phase Composite Nanofibers via Electrospinning of Latex Containing Nanocapsules with Core-Shell Morphology

Nanocapsules containing hexadecane (HD) as core material and polystyrene (PS) as shell, were electrospun with polyethylene oxide (PEO) as a matrix material into the fiber webs. The morphology and thermal properties of PEO fibers containing (1) both PS nanocapsules with core-shell morphology and solid PS particles, (2) only solid PS particles, and (3) without any PS particles, were compared and the effect of PEO concentration on morphology of the resultant fibers have been studied. The resultant fibers were characterized by means of Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). Both TEM observation and DSC analyses confirmed that the PS nanocapsules were encapsulated within the PEO nanofibers. The fibers had an average diameter of 950 nm for nanocapsules containing parts, 300 nm for solid particles containing parts, and 150 nm for usual parts. The phase change temperatures and phase transition heat of the produced fibers were determined by DSC analyses. TGA was also used to confirm the preparation of multi phase fibers and to determine the amount of HD within the fibers.     

合成革用有机硅改性脂肪族聚氨酯树脂的合成及应用

采用聚酯多元醇、异佛尔酮二异氰酸酯(IPDI)、聚醚改性聚硅氧烷(PO-PDMS)等为主要原料合成了有机硅改性脂肪族聚氨酯树脂.考察了不同有机硅含量对聚合物状态、力学性能、耐水性和耐黄变性能的影响,以及有机硅改性脂肪族聚氨酯树脂在合成革上的应用性能.结果表明,相对于物理共混,将PO-PDMS与聚氨酯共聚可有效提高有机硅...     

滑石粉/LDPE核壳结构粒子增强增韧回收PP的研究

研究了以滑石粉为硬核、低熔点高熔体流动速率低密度聚乙(烯LDPE)为软壳的核壳结构粒子的制备方法,并用该核壳结构粒子与回收PP进行共混改性,研究了核壳结构粒子对回收PP复合材料力学性能、加工流动性能和耐热性能的影响。结果表明:当核壳结构粒子用量为30份时,复合材料的缺口冲击强度为16.1 J/m,拉伸强度为28.79 MPa,弯曲强度为39.01 MPa,弯曲模量为1 535 MPa;用滑石粉/低熔点高MFR的LDPE制备的核壳结构粒子填充回收PP后的复合材料的熔体流动性较好适,合工业化生产。     

核壳结构纳米TiO_2/丁苯复合乳液制备研究

以硅烷偶联剂改性的纳米TiO2为核,阴离子乳化剂十二烷基硫酸钠(SDS)与非离子乳化剂壬基酚聚氧乙烯醚(OP-10)为复合乳化剂,其质量比为1:1,采用半连续种子乳液聚合法,制备了具有核壳结构的纳米TiO2/聚丁苯(PSB)复合乳液,其固含量最高可达50%以上,黏度可依据不同使用要求进行调节。     

核壳结构免烧轻骨料的制备与性能研究

针对核壳结构免烧轻骨料的制备技术,研究采用单颗承载力来表征人造轻骨料的力学性能,研究了石灰掺量、水泥掺量、不同养护方式下成熟度模数对免烧轻骨科性能的影响,同时研究了核壳结构免烧轻骨料的耐高温性能.结果表明,单颗承载力与筒压强度具有良好的相关性,石灰掺量对粉煤灰掺量为50％的轻骨料力学性能影响较小,水泥掺量对轻骨料力学性能影响较大.成熟度模数对早期力学性能影响较大,随着成熟度模数的增加,7d承载力几乎成线性增加,但对28 d力学性能影响不大.所制备的核壳免烧型骨料,承载力与烧结陶粒相比存在明显优势,具有良好的耐高温性能,400℃时强度不下降,600℃时颗粒仍保持完整,承载力降低约35％,可用于结构自保温材料.     

羟基硅油原位改性制备疏水性沉淀二氧化硅

采用羟基硅油原位改性制备疏水性沉淀二氧化硅。红外光谱（FT-IR）分析表明,羟基硅油通过化学键接枝到二氧化硅表面。扫描电镜（SEM）分析表明,原位改性改善了沉淀二氧化硅的团聚现象,使之分散性提高,与有机基体聚丙烯树脂的相容性增大。疏水性测试表明,羟基硅油203-B和203-D的用量（羟基硅油与原料中二氧化硅的质量比）达到17.9%时,疏水度分别达到24.59%和22.17%,羟基硅油相对分子质量越小,羟基含量越高,改性效果越明显。原位改性使沉淀二氧化硅吸油率降低。     

自交联有机硅乳液的制备及其应用

采用机械反相乳化法,将甲基含氢硅油和端羟基二甲基硅油制备成自交联复合乳液。研究了乳化剂、乳化工艺、活性功能基氢和羟基含量,以及相对分子质量对乳液稳定性的影响。考察了自交联复合乳液的憎水防污性能。探讨了复合乳液的一些典型应用。     

Preparation and Properties of a Waterborne Contact Adhesive Based on Polychloroprene Latex and Styrene-Acrylate Emulsion Blend

Environmental protection and legislative pressure to eliminate the use of solvents in the adhesive industry have inspired the search for safer alternatives. In the area of contact adhesives, the waterborne route has proved to be of particular interest. Based on the synergistic effect of polychloroprene latex and styreneacrylate emulsion, a waterborne contact adhesive consisting of polychloroprene latex (PCL) and styreneacrylate emulsion (SAE) blend has been developed. In order to blend PCL with SAE easily and to accelerate the drying rate of the adhesive, boric acid was chosen for use in the PCL/SAE blend system. Effects of boric acid and SAE content on the properties of PCL/SAE blends, such as pH value, storage stability and set time, were investigated. At the same time, the effect of SAE content on the mechanical properties of PCL/SAE blend films was studied. The morphology of blend films was characterized by Atomic Force Microscopy. The adhesive performance of the waterborne contact adhesive was evaluated by peel and shear tests. The results showed that when the waterborne contact adhesive formulation contained 40 wt% styrene-acrylate emulsion (dry weight) and 1.25 wt% boric acid, it had a good shelf-stability, its set time was 5 min, and the blend film with this formulation was ductile and flexible with reasonably good tensile strength and very high elongation at break. And the blend films showed structure with a sea–island morphology. The waterborne contact adhesives derived from PCL/SAE blends were found to be comparable to the commercially available solvent-based contact adhesives. The synergistic effect of polychloroprene latex and styrene-acrylate copolymer emulsion was also discussed.     

高抗撕裂硅橡胶复合材料的制备

研究了羟基硅油和四甲基四乙烯基环四硅氧烷(V 4)对气相法白炭黑增强甲基乙烯基硅橡胶(VMQ)复合材料性能的影响。结果表明,在VMQ用量为100份、气相法白炭黑用量为40份时,加入羟基硅油可明显降低混炼胶的Payne效应,有效改善白炭黑的分散性;当其用量为5份时,复合材料的综合力学性能最优。在添加5份羟基硅油的基础上,加入V 4可显著提高VMQ复合材料的撕裂强度,其用量为4份时,撕裂强度可达42.2 k N/m。     

半连续细乳液聚合制备含氟乳胶粒子及性能研究

以甲基丙烯酸十二氟庚酯(DFM)单独作为助稳定剂进行苯乙烯半连续细乳液聚合,并对其最终乳液成膜表面进行疏水性能研究。考察了不同DFM用量作为助稳定剂对苯乙烯细乳液聚合过程中单体转化率、初始单体液滴粒径和数目、最终乳胶粒子粒径和数目的影响及成核机理研究;并采用含氟混合单体的细乳液组分进行半连续细乳液聚合。结果表明:细乳液聚合中,当DFM用量在15%(wt)时,最终乳胶粒子数目和初始液体数目比值为1.03,说明细乳液聚合以单体液滴成核为主体。在半连续聚合中,在苯乙烯94.0%转化率滴加细乳液组分产生次生粒子的比例仅为0.05;对其乳胶粒子成膜表面进行研究,发现水接触角可达113±2°。半连续细乳液聚合有效降低DFM用量,成膜表面疏水性良好。     

核壳型丙烯酸酯乳液的制备与性能研究

采用甲基丙烯酸甲酯／丙烯酸丁酯作复合单体,丙烯酸为功能单体,通过预乳化半连续种子乳液聚合工艺合成了核壳型丙烯酸酯乳液,讨论了反应温度、乳化剂用量、核壳单体质量比以及丙烯酸加入量对乳液性能以及漆膜力学性能的影响,并用TEM对乳胶粒子进行了表征。结果表明：采用预乳化半连续滴加法,当复合乳化剂SDS与OP-10质量比为2：1且总用量为4％,核、壳层中甲基丙烯酸甲酯与丙烯酸丁酯的质量比分别为3：7和4：1,核壳总单体质量比为1：1,丙烯酸质量分数为4％,核层和壳层反应温度分别为70℃和80％时,可以合成黏度适中、乳胶粒粒径分布均匀、稳定性好和漆膜力学性能优良的核壳型丙烯酸酯乳液。     

含硅羟基丙烯酸酯乳液的合成

采用单体预乳化方法结合半连续种子乳液聚合工艺,制得了耐水性好和附着力高的舍硅羟基丙烯酸酯乳液.考察了乳化剂用量、引发剂用量、羟基单体用量、有机硅单体用量与引入方式对乳液聚合稳定性的影响.结果表明:当w(乳化剂B)为0.90%、w(引发剂)为0.45%、w(HEA)为10%、w(A-151)为5%时,合成的含硅羟基丙烯酸...     

硅橡胶厚功能制品的制备工艺研究

研究了不同结构化控制剂搭配、硫化剂和减振填料用量对硅橡胶性能的影响,硫化时间、升温间隔对硅橡胶硫化效果的影响,脱模温度、放气量、工装设备对硅橡胶制品质量的影响。结果表明,采用高摩尔质量硅橡胶、气相法白炭黑,配合适量的结构化控制剂,可制备拉伸强度8 MPa以上、无结构化的硅橡胶;随着减振填料的大量填充,硅橡胶的力学性能呈下降趋势;随着硫化胶放气量的增加,大尺寸制品芯部有开裂的倾向。硅橡胶混炼胶用过氧化二异丙苯作硫化剂,采用分段升温、长时间硫化、保压降温工艺,可获得密实无缺陷的厚型制品。较佳工艺为:100份摩尔质量大于69×104g/mol的甲基乙烯基硅橡胶生胶、45份气相法白炭黑、6份羟基硅油、1份二甲基二乙氧基硅烷、1～2份DCP、2～5份氧化铁、10～40份减振填料,硫化时间选择厚制品157℃±1℃的传热时间,分段升温值15℃、升温间隔时间10～20 min、平均升温速率0.75℃～1℃/min,脱模温度根据制品厚度选择室温～80℃,放气量0.20%～0.27%,模具采用大间隙和小溢料槽。     

核壳结构纳米TiO_2/丁苯复合乳液制备研究

为制备高固高粘新型丁苯乳液(SBRL),以经硅烷偶联剂改性的纳米TiO2为核,阴离子乳化剂十二烷基硫酸钠(SDS)与非离子乳化剂辛基苯基聚氧乙烯醚(OP-10)为复合乳化剂,其质量比为1:1,采用半连续种子乳液聚合法,制备了具有核壳结构的纳米TiO2/聚丁苯(PSB)复合乳液,并测定了复合乳液的性能。确定了适宜聚合工艺条件:纳米TiO2为总量0.5%,乳化剂用量为3.5%,引发剂用量为单体量0.4%,聚合温度为64℃,可以制备出性能良好的复合乳液。所制乳液固含量最高可达50%以上,粘度可依据不同使用要求调节。     

丙烯酸酯核壳乳液胶膜力学性能研究

采用种子乳液聚合法制备了丙烯酸(AA)/丙烯酰胺(AM)交联的、具有核壳结构的甲基丙烯酸甲酯(MMA)/丙烯酸丁酯(BA)/丙烯腈(AN)复合乳液,研究了壳层软硬单体比、复合交联剂AA/AM及壳层交联单体AN用量对乳液胶膜拉伸强度和断裂伸长率的影响。结果表明:当核层和壳层之间的玻璃化转变温度Tg相近时,核壳乳液核、壳两部分分子链的协调运动能力较强,其乳液胶膜拉伸强度和断裂伸长率都较大;当AA/AM用量不超过4%时,乳液胶膜强度和断裂伸长率随着AA/AM用量增大而增大;随着AN用量的增加,乳液胶膜拉伸强度逐渐增大。     

超细TATB-BTF核-壳型复合粒子的制备

用喷雾干燥法制备了超细TATB-BTF核-壳型复合粒子。通过BTF在TATB表面结晶沉积,达到对超细TATB粒子进行包覆的目的。扫描电镜分析显示粒子表面形态发生了一定变化,表明TATB粒子表面有包覆层,用光电子能谱(XPS)对粒子表面各成分含量进行了分析。对复合粒子的热行为进行了DTA分析。结果表明,核粒大小是影响超细TATB-BTF核-壳型复合粒子包覆效果的主要因素。