用於光学复合材料的紫外光固化莰烯衍生物改性环氧活性大分子单体及其聚合反应

高次球面方程变焦距组合镜头是一种高技术产品，它对用放这类产品的高聚物的性能提出了极为苛刻的要求。遵循分子设计的基本原则，我们进行了新型改性环氧树脂、羟烷基教烯不饱和衍生物，活性多官能交联共聚单体及铁盐的设计与合成，光敏体系的选配，聚合条件的优化及紫外光辐照下安息香乙酸与铁盐复合引发的游离基一阳离子开环共聚反应的研究，并对产物的相关性能进行了系统测定。实验结果表明：兼具软、硬段结构和环氧基、羟基、波基、芳环、醚基的不饱和环氧甲基丙烯酸酯，不仅在250urn，290一310urn有强吸收峰，且在363urn左右还有一个…     

Phase separation of diamine chain-extended poly(urethane) copolymers: FTIR spectroscopy and phase transitions

As part of our continuing effort to understand microphase separation of poly(urethane urea) block copolymers, FTIR spectroscopy and thermal techniques (DSC and DMA) were used to investigate the phase behavior of two series of MDI-polytetramethylene oxide soft segment copolymers, chain-extended with ethylene diamine or a diamine mixture. Due to the complex nature and multiple absorbances in the carbonyl and N-H regions of the FTIR spectra, quantitative analysis was not possible. However, qualitative trends could be discerned, and the spectral changes were found to be in excellent agreement with our previous quantitative analysis of the same copolymers using small-angle X-ray scattering. DSC and DMA experiments both indicate that the soft phase T_g decreases with increasing hard segment content. This is contrary to increased hard segment mixing in the soft phase, but can be rationalized by taking into consideration soft segment crystallinity and the concentration of ‘lone’ MDI units in the soft phase.     

Synthesis and phase separation during film formation of novel methyl methacrylate/n-butyl acrylate/methacrylic acid (MMA/BA/MAA) hybrid urethane/acrylate colloidal dispersions

Hybrid acrylic/urethane colloidal dispersions were prepared by incorporation of a novel multifunctional urethane castor vinyl ether (UCVE) macromonomer derived from castor oil in acrylic latexes. Single-stage and two-stage semi-continuous emulsion polymerization processes were utilized to control placement of UCVE in colloidal dispersions with core/shell and spherical particle morphologies. While the single-stage process resulted in optically clear and chemically homogeneous films, the two-stage process led to heterogeneous film formation. Internal reflection infrared imaging (IRIRI) spectroscopic analysis of the film-air (F-A) interfaces revealed phase-separated urethane- and urea-rich domains ranging in size from approximately 4-40 μm. Based on these measurements, a model of film formation is proposed which incorporates the effect of exceedingly high shear conditions to achieve fine dispersions of UCVE. These experiments indicate that features of the single-stage process facilitate uniform dispersion of UCVE and efficient grafting between UCVE and the acrylic polymer matrix resulting in intimately mixed networks and homogeneous films.     

Structure formation and characterization of EVAL membranes with cosolvent of isopropanol and water

Microporous poly (ethylene-co-vinyl alcohol) (EVAL) membranes can be prepared by the solution casting method in combination of thermally induced phase separation (TIPS) with solvent evaporation. A cosolvent of isopropanol and water (3:2 w/w) is used to prepare the casting solution. EVAL membranes of different bulk or true densities, porosity, flexibility, crystallinity, and structure can be obtained by adjusting the casting temperature. A pseudo-binary temperature-concentration phase diagram of the EVAL-cosolvent system has been proposed, based on the information obtained from SEM, DSC, and light transmittance studies, to account for the membrane formation mechanism. The dense membranes were obtained when the casting temperature was higher than the upper critical solution temperature (UCST) of the system, but they might contain some nonSEM-observable micropores if the casting temperature was below the glass transition temperature (T_g) of EVAL. The porous and the least crystalline membranes with a honeycomb-like morphology were obtained through liquid-liquid demixing and vitrification at a casting temperature between the UCST and the dynamic crystallization temperature (T_c). Highly porous and crystalline membranes were obtained when they were prepared at temperatures near T_c. In this case, the particulate membranes were resulted from solid-liquid demixing mainly via TIPS, and membranes with leafy morphology were created through liquid-liquid demixing and then followed with immediately crystallization.     

CaO－Al_2O_3－SiO_2系玻璃表面成核及分相对其作用的研究

ＣａＯ－Ａｌ＿２Ｏ＿３－ＳｉＯ＿２系玻璃表面成核及分相对其作用的研究杨晓晶，李家治，许淑惠（中国科学院上海硅酸盐研究所２０００５０）（西北轻工业学院７１２０８１）ＡＳｔｕｄｙｏｎｔｈｅＳｕｒｆａｃｅＮｕｃｌｅａｔｉｏｎａｎｄｔｈｅＩｎｆｌｕｅｎｃｅｏ...     

Phase distribution and separation in poly(2-acetoxyethyl methacrylate)/polystyrene latex interpenetrating polymer networks

A series of latex interpenetrating polymer networks (LIPNs) were prepared via two-stage soap-free emulsion polymerization of styrene on cross-linked poly(2-acetoxyethyl methacrylate) (PAEMA) seed latexes, using potassium persulfate as initiator. It was found that a compositional gradient was present when PAEMA seeds cross-linked either lightly or highly were used. The polystyrene (PS) phase is localized near the particle center in the former case, while it is segregated near the surface in the latter case. A uniform distribution of PS phase in LIPN was formed, if moderately cross-linked PAEMA seed was used. All the LIPNs appeared to be microphase-separated, and increase of cross-linking degree in seed latexes decreased the PS-rich domain size. The results were explained by the particle growth mechanism that involved the formation of surface-active oligomeric radicals in water phase, adsorption of the radicals onto monomer-swollen particle/water interface, and chain propagation in the interface with subsequent phase migration dominated by the competitive effects of thermodynamics and kinetics.     

Attenuation of concentration fluctuations after a quench to a temperature in the single-phase region

Attenuation of concentration fluctuations in a polystyrene/poly(2-chlorostyrene) blend after a quench from a temperature in the spinodal region to one in the single-phase region was studied by using the time-resolved light scattering technique and a scanning electron microscope. The characteristic wave number q_m, where the maximum of the scattered light intensity was located, move towards smaller values during the attenuation process. The corresponding growth of the wave length of the dominant concentration fluctuation was clearly observed by the electron microscope. The scattered light intensities at small wave numbers were found to increase before they attenuated. In the later period the power-law behavior q_m∼t^−0.3 was observed. The exponent was smaller than the value (0.5) obtained on the basis of the non-linear theory by Akcasu and collaborators.     

Concept for diamond 3-D integrated UV sensor

In this investigation we present a novel technology for three-dimensional integration of diamond sensors and actuators. Based on a previously developed technology for the integration of a 3-D CMOS camera stack, in this attempt nano-crystalline diamond layers on silicon are used at the sensor level. The processing steps involve silicon thinning, through-silicon etching and metallization, as well as a soldering process using inter-metallic diffusion. Strong emphasis lies on a low thermal budget process, making the technology suitable for backend processing. The concept is demonstrated, however active CMOS chips are not yet implemented. First electrical measurements of the through-connected UV sensors are presented.     

Stereolithography as a manufacturing method for a hierarchically porous ZSM-5 zeolite structure with adsorption capabilities

Hierarchically porous structures are important in adsorption applications and can be used in gas treatment. Hierarchy in adsorbents offers flow channels on different scales, resulting in fast gas flow into a structure. Additive manufacturing, a technology capable of forming intricate geometries, was seen as a potential method to form porous adsorption structures. Stereolithography was chosen as the fabrication method for hierarchically porous zeolite structures because of its high resolution and superior forming capability. The focus of this study was on tailoring the properties of light-cured resin to maximize stability during shaping and shape retention in the debinding stage. Successful slurry preparation was required for demonstrating that monoliths with channel geometry and retained adsorption properties can be manufactured with stereolithography. The final printed structures exhibited hierarchical porosity consisting of flow channels, macropores between the primary particles and the characteristic microporosity of zeolite framework. The structure was manufactured by using blue light to cure layers of resin containing ZSM-5 zeolite. An appropriate debinding heat-treatment cycle was generated based on the TGA and DSC thermal analysis results. The properties of the porous structure were analysed by comparing the BET surface area, XRD patterns and SEM images of as-received powder and a debound piece. The measured BET adsorption properties of the final monoliths remained comparable to the as-received ZSM-5 powder. Based on this study, stereolithography can be utilized to manufacture porous zeolite structures.     

3D printing of dense and porous alkali-activated refractory wastes via Direct Ink Writing (DIW)

Alkali-activated pastes prepared starting from refractory wastes were successfully 3D-printed via Direct Ink Writing. In particular, as raw powders, two different aluminosilicates were used: chamotte (CH, mainly composed of corundum, mullite and andalusite) and alumina-zirconia-silica (AZS, mainly baddeleyite, corundum and amorphous silica). First, pastes rheological parameters were optimized in terms of liquid-to-solid ratio and polyethylene glycol content. Then, both dense prismatic samples and lattice structures were successfully 3D-printed. Additionally, PMMA beads of 20 and 60 μm diameter were used to generate an additional porosity in both dense and lattice structures, leading to hierarchically porous materials. Indeed, samples were partially sintered up to 800 °C, to decompose PMMA beads, when present, and provide very high mechanical properties: a flexural strength of approx. 45 MPa was obtained for both AZS and CH dense samples. Moreover, the addition of 30 vol% of PMMA beads leads to macroporous samples without affecting mechanical properties.     

Polystyrenes with macro-intercalated organoclay. Part I. Compounding and characterization

Nanocomposites of polystyrene (PS) were prepared using a melt compounding or co-solvent method. Two commercial PS were used, and two organoclays—one prepared in this laboratory (COPS), and the other commercial Cloisite^® 10A (C10A). The COPS is a product of clay intercalation with a copolymer of styrene and vinyl benzyl tri-methyl ammonium chloride. According to the XRD diffraction data, the clay platelets in COPS and its PNC with PS were relatively well dispersed, i.e. with the interlayer spacings of d₀₀₁=7-8 nm. By contrast, d₀₀₁ in PNC prepared with C10A was only 4 nm. However, the number of clay platelets per stack in PS/COPS was found to be significantly larger than that in PS/C10A, viz. m=3-12, compared to m=2-6. The scanning and transmission electron microscopy indicated that in the PS matrix COPS existed in form of large, immiscible domains.     

Matrix physical structure effect on the electro-optic characteristics of thiol-ene based H-PDLC films

The physical and mechanical properties of several thiol-ene based polymers and their mixtures with the liquid crystal, E7, were characterized to probe their relationship with the liquid crystal film electro-optic performance properties. Kinetic data suggests that high conversion is achieved for each thiol-ene combination. Pre-polymerization phase diagrams indicate that each thiol-ene/E7 mixture phase separates well below room temperature, and thus prior to polymerization at room temperature all are in a single phase. Holographic polymer dispersed liquid crystals (HPDLC) were fabricated for several thiol-ene and E7 mixtures, and electro-optical parameters characterized to probe the relationship between the thiol-ene network properties and the electro-optic performance of the HPDLCs. The photocured matrices exhibited glass transitions and tan δ peak maxima that ranged from temperatures below 0 °C to well above room temperature. There is a clear correlation between the physical nature of the matrix and the electro-optic switching parameters with H-PDLC films fabricated from trithiol-pentaerythritol triallylether, all of which exhibit glass transition temperatures below 0 °C, having the fastest switching times and lowest switching voltages at room temperature. Also, in each case higher liquid crystalline concentration resulted in lower switching voltages.     

Morphology control of various aromatic polyimides by using phase separation during polymerization

Morphology control of various aromatic polyimides representative as poly(4,4′-oxydiphenylene pyromelliteimide) was examined by using the phase separation during solution polymerization. Polymerizations of aromatic dianhydrides and aromatic diamines to the polyimides were carried out in poor solvents at 240-330 °C for 6 h with no stirring. Polymerization concentrations were from 0.25% to 3.0%. The polyimides were obtained as yellow precipitates. Two categorized morphologies were created, which were particles and crystals exhibiting lath-like and plate-like habits. These morphologies of polyimides could be selectively controlled by the polymerization conditions. The higher concentrations, less miscible solvents and lower temperatures were preferable to yield the particles via liquid-liquid phase separation. On the contrary, the lower concentration, miscible solvents and higher temperature were desirable to yield the crystals. The polyimide precipitates showed high crystallinity and possessed excellent thermal stability at which the 10 wt% loss temperatures in N₂ were in the range of 590-694 °C.     

Microstructural organization of polydimethylsiloxane soft segment polyurethanes derived from a single macrodiol

Segmented polyurethane (PU) block copolymers were synthesized using 4,4′-methylenediphenyl diisocyanate and 1,4-butanediol as hard segments and oligomeric ethoxypropyl polydimethylsiloxane (PDMS) as the soft segments, with hard segment contents ranging from 26 to 52 wt%. The microphase separated morphology, phase transitions, and degrees of phase separation of these novel copolymers were investigated using a variety of experimental methods. Like similar copolymers with mixed ethoxypropyl PDMS/poly(hexamethylene oxide) soft segments, PU copolymers containing only ethoxypropyl PDMS soft segments were found to consist of three microphases: a PDMS matrix phase, hard domains, and a mixed phase containing ethoxypropyl end group segments and dissolved short hard segments. Analysis of unlike segment demixing using small-angle X-ray scattering demonstrates that degrees of phase separation increase significantly as copolymer hard segment content increases, in keeping with findings from Fourier transform infrared spectroscopy measurements.     

超高分子量聚乙烯微孔材料微观结构形成机理的研究 (I)相分离过程对微观结构的影响

超高分子量聚乙烯（ＵＨＭＷＰＥ）微孔材料是以ＵＨＭＷＰＥ为聚合物基体的一种新型功能性材料,利用这种材料能够实现非均相分离、过滤及离子通透等多种单元操作过程,可广泛地应用于化工、医药、能源等领域［１］。针对ＵＨＭＷＰＥ物料的特殊性能,采用热致相分离方法［２］（ＴＩＰＳ）进行微孔材料的成型。ＴＩＰＳ过程涉及到聚合物－溶剂二元体系,因此对ＴＩＰＳ的二元体系热力学过程进行了研究。同时,二元体系的相分离过程对微观结构有很大影响。结合ＵＨＭＷＰＥ－石蜡油二元体系相图可以知道,该二元体系的相分离由两种不同的相分离过程组成———固液相分离和液液相分离,研究了两种分离过程对最终微观结构的影响。     

Structural and morphological development in poly(ethylene-co-hexene) and poly(ethylene-co-butylene) blends due to the competition between liquid-liquid phase separation and crystallization

Isothermal crystallization behavior of poly(ethylene-co-hexene) (PEH) and the 50/50 blend (H50) of PEH with amorphous poly(ethylene-co-butylene) (PEB) was studied by time-resolved synchrotron simultaneous small-angle X-ray scattering/wide-angle X-ray diffraction (SAXS/WAXD) techniques and optical microscopy (OM). The X-ray study revealed the changes of structural and morphological variables such as the scattering invariant, crystallinity and lamellar long period, et al. In H50, the lamellar morphology was found to be dependent on competition between liquid-liquid phase separation (LLPS) and crystallization. At high temperature, LLPS becomes dominating, resulted in crystallization of PEH with minimal influence of PEB. At low temperature, LLPS is suppressed, PEB component shows obvious influence on PEH crystallization, PEB is thought to be partially included into PEH lamellar stacks and PEH-PEB co-crystallization is unlikely, however, possible. Optical microscopy was used to monitor crystal nucleation and growth rates in PEH and H50, providing complementary information about the effect of temperature on LLPS and crystallization. Real-space lamellar morphologies in PEH and H50 were characterized by atomic force microscopy (AFM), PEH exhibited sheaf-like spherulites while H50 exhibited hedrites. Overall, the competition between LLPS and crystallization in H50 blend influences the structural and morphological development. Controlling the interplay between LLPS and crystallization of PEH/PEB blends, it is possible to control the structure and morphology as practically needed.     

Morphological architecture of poly(p-oxybenzoyl) by modification of oligomer end-group

Influence of oligomer end-group on morphology of poly(4-oxybenzoyl) (POB) was examined by polymerizations of 4-acyloxybenzoic acids having different acyl groups. Polymerizations of 4-propionyloxybenzoic acid, 4-hexanoyloxybenzoic acid, 4-octanoyloxybenzoic acid and 4-decanoyloxybenzoic acid in liquid paraffin at 320 °C yielded needle-like or pillar-like POB crystals via crystallization of oligomers. On the other hand, the polymerization of 4-perfluorooctanoyloxybenzoic acid (FOBA) afforded microspheres having needle-like crystals on the surfaces. At an initial stage in the polymerization, microspheres having smooth surface were formed via liquid-liquid phase separation of oligomers prepared from FOBA owing to the low miscibility of perfluorooctanoyl end-group. Thereby the phase-separation behaviour of oligomers changed from liquid-liquid phase separation to crystallization at a middle stage in the polymerization and then needle-like crystals were formed on the surface of the microspheres. Chemical structure of the oligomer end-group affected significantly the phase-separation behaviour of oligomers and ultimately the morphology of POB.     

Fabrication of super-hydrophobic film from PMMA with intrinsic water contact angle below 90°

Super-hydrophobic film is commonly prepared from hydrophobic materials. Poly(methyl methacrylate) (PMMA) is considered as a hydrophilic polymer (intrinsic contact angle below 90°) with the water contact angle (CA) of 68°. However, a super-hydrophobic PMMA film with CA of 154° was obtained by treating polystyrene (PS) and PMMA blended film in a warm selective solvent, cyclohexane. The surface was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (FT-IR). The results show that the conversion from the hydrophilic surface to a super-hydrophobic one is due to the cooperation of the micro-, nano-structure and the side group reorientation in the PMMA chains at the topmost.