含氟聚氨酯-丙烯酸酯核壳乳液的制备及性能

以甲基丙烯酸羟乙酯封端的水性聚氨酯作为大分子单体,与甲基丙烯酸甲酯及甲基丙烯酸全氟烷基乙基酯在乳液中进行自由基共聚合,制备出具有核壳结构的水性含氟聚氨酯-丙烯酸酯乳液。通过激光粒度分析仪、FT-IR、DSC、TGA、接触角、力学等表征手段,对乳液及其乳胶膜的结构和性能进行了研究,还着重探讨了甲基丙烯酸全氟烷基乙基酯的含量对乳胶膜性能的影响,结果表明:所制得的材料具有预期结构,并且具有优异的表面性能和力学性能,氟单体的引入使乳胶膜的表面能大大降低,而力学性能明显提高。     

含氟聚氨酯-丙烯酸酯核壳乳液的制备及性能

以甲基丙烯酸羟乙酯封端的水性聚氨酯作为大分子单体,与甲基丙烯酸甲酯及甲基丙烯酸全氟烷基乙基酯在乳液中进行自由基共聚合,制得具有核壳结构的水性含氟聚氨酯-丙烯酸酯乳液。通过激光粒度分析、FT-IR、DSC、TGA、表面性能测试、力学性能测试等表征手段,对乳液及其乳胶膜的结构和性能进行了检测,另外,还着重探讨了甲基丙烯酸全氟烷基乙基酯的含量对乳胶膜性能的影响。结果表明:所制得的材料具有预期结构,并且表面能及吸水率低,力学性能优异。氟单体的引入使乳胶膜的表面能大大降低,而力学性能明显提高。     

中和度对聚酯型阴离子水性聚氨酯性能的影响

采用预聚体法,以聚酯多元醇、甲苯二异氰酸酯、二羟甲基丙酸（DMPA）制备了聚酯型阴离子水性聚氨酯乳液,考察了中和度对乳液的粒径、运动黏度以及胶膜力学性能的影响。结果表明,随着中和度的增加,水性聚氨酯乳液的粒径减小;运动黏度增大;水性聚氨酯胶膜的耐水性先增大后减小;胶膜的拉伸强度提高,但其断裂伸长率降低。以三乙胺为中和剂...     

有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的制备

将磺酸型聚酯多元醇、异佛尔酮二异氰酸酯（IPDI)和三羟甲基丙烷(TMP)在无有机溶剂参与的情况下进行预缩聚,以硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）作为改性剂,加入双官能团单体甲基丙烯酸-β-羟乙酯(HEMA),得到含乙烯基和有机硅封端的聚氨酯作为种子乳液,然后与甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)混合单体共聚,合成了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液。 红外光谱的表征确定了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的化学结构;透射电子显微镜观察证实了此复合乳液具有明显的核壳结构;热重分析表明,经有机硅和丙烯酸酯改性后,胶膜的最大热失重温度提高了20 ℃,X射线衍射分析表明胶膜的结晶度降低,有利于提高膜的韧性。 力学性能测试及吸水率测试结果表明,当有机硅含量为1.9%时,胶膜的拉伸强度最高达到25.03 MPa,断裂伸长率为328%,此时膜的吸水率最低。     

环氧大豆油多元醇改性磺酸型水性聚氨酯合成与性能研究

用2-乙基己醇(异辛醇)对环氧大豆油进行开环,生成环氧大豆油多元醇,并利用其对由异佛尔酮二异氰酸酯(IPDI)、聚己内酯二元醇(PCL)和乙二胺基乙磺酸钠(AAS)为主要合成原料的磺酸型水性聚氨酯(SWPU)进行改性,考察了不同多元醇含量对磺酸型水性聚氨酯乳液以及胶膜性能的影响.首先,通过FTIR和1H-NMR证实了环氧大豆油多元醇的合成;然后经过粒径测试、耐水性测试、接触角测试、机械性能测试、TG测试等检测表明:磺酸型水性聚氨酯成功合成,随着多元醇含量的增加,水性聚氨酯乳液粒径逐渐增大;胶膜的吸水率逐渐减小,并趋于平缓;力学性能拉伸强度逐渐增强,而断裂伸长率下降.但当环氧大豆油多元醇添加量过大时,导致最后乳液无法分散,乳化失败.当多元醇含量与PCL质量比为0.2时,胶膜吸水率由50.14%减小至12.27%,接触角为103.3°,拉伸强度由8.16 MPa增至21.77 MPa.通过TG表明,分子结构中多元醇的引入,胶膜的耐热性有明显提高.     

丙烯酸酯纳米乳液的制备与表征

将甲基丙烯酸羟乙酯(HEMA)与甲基丙烯酸(MAA)或丙烯酸(AA)用作甲基丙烯酸甲酯(MMA)／丙烯酸丁酯(BA)乳液聚合体系的反应性助乳化剂，采用一种改进的微乳液聚合方法，合成了高单体／乳化剂比例(大于40：1)的聚丙烯酸酯纳米乳液．讨论了引发剂、乳化剂、助乳化别对乳胶粒大小和胶膜吸水率的影响，并对乳液的流体力学行为，共聚物的拉伸行为及耐水性等进行了研究．     

丙烯酸酯改性水性聚氨酯/纳米二氧化硅复合材料的制备和性能

利用原位聚合伴随溶胶-凝胶进行的过程,合成了丙烯酸酯改性聚氨酯(PUA)/纳米SiO₂(PUAS)复合乳液。 通过纳米粒度仪、扫描电子显微镜、透射电子显微镜和热重分析仪等技术手段表征了复合乳液及胶膜的结构和性能。 结果表明,纳米SiO₂能够均匀地分散在复合材料中,随着原料中前驱体正硅酸乙酯(TEOS)质量分数的增加,复合乳液粒径有所增大,胶膜力学性能和热稳定性明显提高。 当TEOS质量分数为8%,胶膜拉伸强度达到16.8 MPa,邵氏硬度A达到94,最大分解速率温度提高到416 ℃,且胶膜耐水性明显改善,吸水率降低到2.1%。     

单油酸三羟甲基丙烷酯改性水性聚氨酯

利用单油酸三羟甲基丙烷酯(TMPM)、异佛尔酮二异氰酸酯(IPDI)和聚氧化丙烯(PPG)等制备水性聚氨酯。采用透射电镜(TEM)、动态激光光散射(DLLS)、红外光谱(FT-IR)、热重分析(TGA)和表面张力仪表征了乳液胶束形态、产物结构及性能。结果表明:水性聚氨酯(PU)分子上引入脂肪侧链容易在水中形成规整的胶束,但TMPM改性的水性聚氨酯胶束粒径随TMPM含量的增加不断增大,当w(TMPM)=0.07时,乳液不稳定;脂肪侧链的引入降低了水性聚氨酯乳液的表面张力,表面张力随着反应体系中—NCO和—OH摩尔比的增大而降低,随交联度的增大先增加后减小;TMPM的引入可以提高胶膜的热稳定性。     

水性聚氨酯结构与胶膜性能的关系

为制备一种性能优异的水性聚氨酯涂层,以聚丙二醇和异佛尔酮二异氰酸酯为主要原料,用本体聚合法制备了水性聚氨酯,考察了结构组元对胶膜性能的影响,并用激光粒度仪、微机控制电子万能试验机和同步热分析仪进行了表征。结果表明:当硬段含量增加时,乳液粒径增大,胶膜拉伸强度增加,吸水率升高;当异氰酸根指数增大时,乳液粒径增大,胶膜拉伸强度增加,吸水率降低;当亲水性扩链剂含量和中和度增大时,乳液粒径减小,胶膜的拉伸强度增加,吸水率升高;在硬段比例为50%、异氰酸酯指数为1.35、亲水性扩链剂含量为5%、中和度为1的条件下,胶膜性能较佳(拉伸强度为16MPa,断裂伸长率为556%,吸水率为6.2%)且在丙酮和甲苯中均表现出溶胀现象。     

有机硅改性聚氨酯丙烯酸酯细乳液的制备及性能

将自制的聚氨酯大单体与含乙烯基有机硅单体、丙烯酸酯进行共聚反应,通过合适的工艺条件,制备了一系列性能稳定的细乳液。研究了聚合方法、有机硅含量对共聚细乳液及胶膜性能的影响。结果表明,种子细乳液法制得的聚合物结构明确,细乳液粒径均在150 nm左右,分布指数约为0.07,有机硅的引入使乳液胶膜耐水性及耐高温性得到了明显提高。     

Preparation of micron-sized composite polymer particles containing hydrophilic 2-hydroxyethyl methacrylate and their biomedical applications

Micron-sized polystyrene or PS particles were first prepared by dispersion polymerization. Then a series of polystyrene/poly(styrene-2-hydroxyethyl methacrylate) or PS/P(S-HEMA) composite polymer particles was prepared by seeded copolymerization using different amounts of 2-hydroxyethyl methacrylate (HEMA) at the constant core/shell ratio of 1/0.5. The produced PS seed and composite polymer particles were characterized by transmission electron microscopy. Adsorption behaviors of some biologically active macromolecules were studied under similar conditions. In each case the magnitude of adsorption on composite polymer particles decreased with the increase in HEMA content in the recipe, which means that the hydrophobic interaction between the surface of the particles and biomolecules decreased. The specific activities of trypsin aqueous solution and adsorbed trypsin on PS seed and composite polymer particles prepared with different HEMA contents were also measured and compared. The activity of adsorbed trypsin on composite polymer particles improved significantly with the incorporation of hydrophilic HEMA.     

Hydroplasticization effect in structured latex particles film formation

Series of emulsion copolymers with structured particles were synthesized comprising copolymerized acrylic or methacrylic acid in the outer layer. All samples were based on particles, containing identical cores slightly crosslinked by allyl methacrylate and variable shells, weight ratio core/shell being constant 1/1. Each sample contained 10 wt% HEMA in the shell to achieve the film crosslinkability. In both series samples with different hardness and polarity (varible styrene/butyl acrylate ratio) of the shell layer were prepared. It was shown that the extent of particle swelling and hydroplasticization depends not only on the content of dissociated carboxylic groups, but also on the composition and crosslinking of the rest of polymer chain i.e. on its polarity and rigidity and on the origin of carboxylic groups. The effect of dissociated carboxylic groups on lowering the minimum film forming temperature was much more pronounced if the polymer chains were more polar.     

GHD室温自交联乳液的聚合及贮存稳定性

采用半连续种子乳液聚合技术合成了含甲基丙烯酸缩水甘油酯(GMA)、甲基丙烯酸羟乙酯(HEMA)和甲基丙烯酸二甲氨基乙酯(DMAEMA)的室温自交联乳液(GHD).实验结果表明,在甲基丙烯酸甲酯(MMA)-丙烯酸丁酯(BA)-GMA种子乳液存在下,聚合温度升高,聚合过程稳定性下降,但乳液的贮存稳定性提高;乳化单体滴加速度加快,种子聚合物的玻璃化温度升高,可减少聚合过程的交联凝聚作用,提高聚合过程的稳定性;而HEMA和DMAEMA用量增加对聚合过程的稳定性没有明显影响,但使乳液的贮存稳定性下降.官能团间的交联凝聚作用可能是影响室温自交联乳液聚合及贮存过程稳定性的关键因素.     

EFFECT OF 2-HYDROXYETHYL METHACRYLATE ON SEMIBATCH EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYLMETHACRYLATE AND BUTYL ACRYLATE

IINTRODUCTIONSemibatchemulsionpolymerizationisanimportalmethodfortheproductionofpolymersforthecoatingsandadhesivesindustries.Thetraditionallatexproductsaregenerallystabilizedbyemulsifiers.However,theemulsifiersremaininginthelatexproductcanhaveanegativeeffectontheapplicationpropertiessuchasadhesiontosubstratesandfilmformationandwaterresistanceofthecoatingmaterials,becausethesmallandmobileemulsifiermoleculestendtomigratetothesurfacelayerofthepolymericfilm.Withtheemulsifier-freeemulsionpolym…     

EFFECT OF 2—HYDROXYETHYL METHACRYLATE ON SEMIBATCH EMULSIFIER—FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

The semibatch emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate(BA) in the presence of 2-hydroxyethyl methacrylate(HEMA) initiated by K2S2O8(PSP) was studied.The latex particles can maintain an appreciable stability during the emulsifier-free emulsion copolymerization of MMA and BA in the presence of HEMA.The average particle diameter increase with an increase of total solids content,HEMA content,PSP content,ionic strength of the system and monomer feed rate,and decrease with the monomer feed ration from 3/1 (MMA/BA:molar ration).to 1/3.The stability of this reaction system is improved by adding HEMA as nonionic comonomer,High solids content (50%) latex with monodisperse particle can be obtained using this process.     

Estimation of heterogeneous surface structure of submicron-sized,composite polymer particles consisting of hydrophobic and hydrophilic components by atomic force microscopy*

Surface structure of submicron-sized poly(styrene/2-hydroxyethyl methacrylate) [P(S/HEMA)] composite particles produced by emulsifier-free emulsion polymerization was estimated with atomic force microscopy (AFM). AFM force curves were measured in water at different points of the particle surface; it was clarified that the particle surface had a heterogeneous structure consisting of hard and soft parts, which must be, respectively, based on styrene-rich and 2-hydroxyethyl methacrylate-rich parts.     

Semibatch Emulsifier-free Emulsion Copolymerization of Methyl Methacrylate and n-Butyl Acrylate in the Presence of 2-Hydroxyethyl Methacrylate

ThemethodsofimProvingthestabilityofemulsifier-freeemulsionpolymerizationhavebeenreportedinliteraturet(a)choosingionizableinitiators,suchaspotassiumpersulfate'andazo-bis(isobutyramidinehydrochloride)';(b)copolymerizationwithhydrophiliccomonomers,whichinvolvestheionictypesuchascarboxylicmonomers',sulfoderivativesofvinylmonomers',andthenonionictypesuchasglycidylmethacrylate';(c)copolymerizationwithsurface-activemonomers,suchassulfodecylslyrylether';(d)addingorganicsolventstothesystem,suchasmethano…     

Synthesis and characterization of a novel fluorine-containing polymer emulsion with core/shell structure

A novel fluorine-containing polymer emulsion 4 with core/shell structure was synthesized in water phase by a two-stage emulsion polymerization technique using monomer 3 (i.e., 2-methacryloyloxyethyl perfluorooctanoate (MAEF)) reacting with the monomers such as butyl acrylate (BA), acrylic acid (AA) and styrene (ST). The monomer 3 was synthesized from the intermediate 2 (pentadecafluoro-octanoyl chloride) reacting with β-hydroxyethyl methacrylate (HEMA). Polymer film were prepared by coating emulsion 4 directly on a cleaned glass plate and allowed to dry at room temperature. Moreover, the characteristics of polymer film such as hydrophobicity, chemical resistance, surface composition, thermal stability, emulsion particle morphology, as well as the film-forming property were also studied.     

Comparative study between core-shell and interpenetrating network structure polyurethane/polyacrylate composite emulsions

Anionic aqueous polyurethane dispersion was prepared by using carboxyl acid group to make the polyurethane dispersible, and then nanograde core-shell and crosslinked IPN structure polyurethane/polyacrylate composite latex (PUA) were synthesized by soap-free emulsion polymerization method with polyurethane dispersion as seed. FTIR, DSC, dynamic light scattering, TEM, ESCA, TGA, electronic tensile machine were employed to investigate the structures and properties of the composite latex and their polymers. Meanwhile the core-shell composite PUA emulsion and the crosslinked IPN composite PUA emulsion were compared. The results showed that the particle morphology of PUA composite emulsion is inverted core-shell structure with polyacrylate as the core and with polyurethane as the shell. The morphology of the crosslinked PUA emulsion was multi-core structure. The surface in core-shell PUA contains rich PU phase. The phase structure of the crosslinked PUA is more uniform. Three transition temperatures are observed for the core-shell composite PUA, two transitions are observed for the film from the crosslinked PUA. The TGA curves of core-shell PUA and crosslinked PUA exhibit two stages, the first stage corresponds to the thermal decomposition of hard segments in seed polyurethane; the second stage corresponds to the decomposition of soft segments in PUA and decomposition of polyacrylate. With the increase of glycidyl methacrylate (GMA) amounts in PUA composite emulsions, the tensile strength of the PUA films as well as the average diameter of the PUA composite emulsion particles increase, the elongation at break of the PUA films decreases.