PTT/ABS合金的相形态及力学性能研究

采用双螺杆挤出机制备了聚对苯二甲酸丙二酯(PTT)/丙烯腈-丁二烯-苯乙烯塑料(ABS)合金,研究了合金组成及增容剂环氧树脂(EP)和苯乙烯-丁二烯-马来酸酐共聚物(SBM)对合金相形态及力学性能的影响.结果表明,未加增容剂的PTT/ABS合金相畴粗大,相界面清晰,合金的拉伸强度、弯曲强度随ABS含量的增加而逐渐降低,...     

一种纤维用新型聚乙二醇固-固相变储能材料

根据固-固相变材料的性质与结构特点,通过分子设计合成出了一种新型的芳香族四羟基化合物——4,4'-二苯基甲烷二异氰酸甘油酯(MTE),同时以4,4'-二苯基甲烷二异氰酸酯(MDI)-MTE为硬段,以聚乙二醇为相变单元和软段,通过原位聚合法制备出了一种聚乙二醇固-固相变储能材料(P-PCM)。利用红外光谱、核磁共振光谱、差示扫描量热法、动态热机械分析法研究了P-PCM的结构、相变行为及热稳定性,表明了P-PCM是一种新型的性能优异的相变材料。由于材料的刚性、可熔融和可溶解性,适合于纤维与织物的加工使用。     

静电纺氧化铝纤维的制备工艺

分别以聚乙烯吡咯烷酮(PVP)和乙酰丙酮铝作为聚合物和氧化铝前驱体,利用溶胶-凝胶法和静电纺丝技术,在合适的工艺条件下得到了形态良好的氧化铝初生混合纤维,并于1300℃烧结1 h后,得到了直径在200 nm左右的α-氧化铝纤维。透射电子显微镜(TEM)结果表明:α-氧化铝纤维是由无数尺寸在7～12 nm之间的晶粒相互融合形成的。研究了不同的升温速率对于氧化铝纤维形态的影响,结果表明:升温速率越小,越有利于氧化铝纤维的成形。通过将初生纤维于不同温度下烧结,讨论了其在热处理过程中的晶相衍变历程。     

顶空-固相微萃取法测定地表水中四乙基铅

建立了满足地表水中四乙基铅限值要求的"顶空-固相微萃取-气质联用法".分析结果表明:采用空调及水浴控温使萃取温度恒定在23.0～24.5℃范围内,结合内标法进行定量分析,标准曲线线性关系良好(r=0.9995),检出限(3.143SD)为O.085μg/L;河流及水库水水样的加标回收率为93.2%～128%,加标样品平...     

低温烧成硼分相生料乳浊釉的研制

以高岭土、石英、长石、天然硼钙石、煅烧ZnO等为原料,制备了K_2O-Na_2O-CaO-ZnO-SiO_2-Al_2O_3-B_2O_3系统分相生料乳浊釉,在1140℃低温烧成,釉面白度可达85.8。分别研究了Al_2O_3、B_2O_3和ZnO含量对釉料乳浊度的影响,并通过对优化配方进行TEM、EDS及XRD测试分析,研究了其乳浊机理。结果表明,随着Al_2O_3含量降低,B_2O_3含量提高,釉面白度有增高趋势;釉层中均匀分散着大量粒径为100nm左右的球形液滴状乳浊粒子,其与基体之间的较大折射率差是釉面产生较高乳浊的主要因素。     

Encapsulation of disperse dye by phase separation technique using poly(styrene‐maleic acid)

C.I. disperse dye blue 60 was encapsulated by poly(styrene‐maleic acid) using phase separation technique, followed by the preparation of the encapsulated disperse dye dispersion. The effects of process conditions on particle size of the dispersion were investigated. The results showed that the particle size of the encapsulated disperse dye dispersion was small, and the stability was excellent when mass ratio of poly(styrene‐maleic acid) to disperse dye (R_p/d), dropping speed of phase separation agent (D_s), disperse dye content in dispersion (C_d), and dispersing time (D_t) were about 20%, 7 mL/min, 5–7.5%, and 1.5 h, respectively. Transmission electron microscope (TEM), zeta potentials, and contact angle indicated that C.I. disperse dye blue 60 was successfully encapsulated by poly(styrene‐maleic acid). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Preparation and study of thermal properties of phase change materials based on paraffin–alumina‐filled polyethylene

Novel phase change materials based on paraffin and alumina‐filled polyethylene (FPE) were prepared using a two‐step process. In the first step, PE is synthesized using metallocene catalyst system. The synthesized PE is subsequently purified, whereas hydrated alumina–PE composites will be formed by the hydrolysis of aluminum organic cocatalyst and dispersion of hydrated alumina in the PE matrix. In the second step, paraffin–alumina‐FPE composites were prepared by using the ex situ technique. Scanning electron microscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry were used to evaluate the structure and thermal properties of the composites. The results show that the incorporation of a suitable amount of alumina into the composites changes their thermal stability. It is also possible to improve the thermophysical properties of the thermal energy storage materials by altering the paraffin ratio to the FPE. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Structure and properties of poly(butylene succinate) filled with lignin: A case of lignosulfonate

A new kind of blend material was prepared by the incorporation of lignosulfonate calcium (LS), as the filler, into biodegradable poly(butylene succinate) (PBS), as the polymeric matrix, with the process of melt mixing and subsequent compression molding. The nucleation of LS improved the crystalline properties of the PBS component in the blends. Combined with the rigidity nature of the LS filler, the Young's modulus values of the blends were enhanced. Furthermore, the introduction of LS in this biodegradable polyester slightly increased the hydrophilicity of the blends, shown as higher values of water uptake at equilibrium; this might facilitate the biodegradation of hydrophobic polyesters. Consequently, this study opened one way of enhancing the rigidity and decreasing the cost of biodegradable PBS‐based polymeric plastics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Advanced chemically induced phase separation in thermosets: Polybenzoxazines toughened with multifunctional thermoplastic main-chain benzoxazine prepolymers

Multifunctional thermoplastic main-chain benzoxazine prepolymers were synthesized and systematically varied in their structure in order to function as high-performance toughener additives. Their unique chemical composition allows multiple covalent crosslinking with many thermoset network systems including benzoxazines and epoxides in conjunction with a defined chemical induced phase separation (CIPS) upon curing. This was successfully shown using a benzoxazine-based thermoset resin matrix as an example. The corresponding morphologies were addressable in a predictable manner and brought into context with the obtained macroscopic mechanical and thermal properties. In this relationship the CIPS process was classified and compared with the literature in more general means for advanced morphology control by differentiating between covalently attached and so-called gradient domain structures. The prepolymers were characterized by ¹H NMR, FT-IR, DSC and TGA. The thermoset morphologies were investigated by TEM and AFM. The fracture toughness (K_Ic) and the elastic modulus (E) were measured by fracture and three point bending experiments. Thermal properties of the resulting films have been tested by DMA.     

Stability of surfactant-free high internal phase emulsions and its tailoring morphology of porous polymers based on the emulsions

Stable water-in-oil (w/o) high internal phase emulsions (HIPEs) having an internal phase of up to 95 vol% were prepared. The poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) copolymer particles were used as stabilizer. The HIPEs prepared with addition of copolymer particles to the aqueous phase were stabilized by copolymer particles initially, followed by the mixture of copolymer particles and copolymer as the particles eventually dissolves in the organic phase, and finally by only copolymer. Stable w/o HIPEs having an internal phase of up to 92 vol% were also formed with P(St-MMA-AA) copolymer dissolved in the organic phase as the sole stabilizer. Porous polymers (polyHIPEs) were prepared based on these two types of surfactant-free HIPEs. The morphology of the polyHIPEs, such as the surface roughness of the voids and average void diameter, were tailored by tuning the internal phase volume fraction, NaCl, copolymer, and crosslinker concentrations.