PZT-IPN阻尼材料的研究进展

阻尼材料广泛应用于交通工具、产业机械、建筑土木、家用电器、精密仪器和军事装备等领域。科学技术的不断发展,对阻尼材料的要求不断提高。本文主要综述了聚合物基压电智能阻尼材料的阻尼机理。并详细分析介绍了聚合物基IPN压电阻尼材料的设计原理及阻尼效果。     

聚氨酯/UP树脂互穿网络硬质泡沫塑料的研究

对聚氨酯/UP树脂互穿网络硬质泡沫塑料体系进行了研究。通过改变UP树脂用量,得到提高压缩强度的优化配方,并对短切玻璃纤维的增强效果进行了研究,同时对该互穿网络微观结构及制备工艺进行了初步探讨。     

n‐Butyl acrylate based latex interpenetrating polymer networks used as processing modifiers and impact modifiers of poly(vinyl chloride)

A latex interpenetrating polymer network (LIPN), consisting of poly(n‐butyl acrylate), poly(n‐butyl acrylate‐co‐ethylhexyl acrylate), and poly(methyl methacrylate‐co‐ethyl acrylate) and labeled PBEM, with 1,4‐butanediol diacrylate as a crosslinking agent was synthesized by three‐stage emulsion polymerization. The initial poly(n‐butyl acrylate) latex was agglomerated by a polymer latex containing an acrylic acid residue and then was encapsulated by poly(n‐butyl acrylate‐co‐ethylhexyl acrylate) and poly(methyl methacrylate‐co‐ethyl acrylate). A polyblend of poly(vinyl chloride) (PVC) and PBEM was prepared through the blending of PVC and PBEM. The morphology and properties of the polyblend were studied. The experimental results showed that the processability and impact resistance of PVC could be enhanced considerably by the blending of 6–10 phr PBEM. This three‐stage LIPN PBEM is a promising modifier for manufacturing rigid PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1168–1173, 2004     

互穿网络敏感型聚氨酯水凝胶的合成与研究

以异佛尔酮二异氰酸酯（IPDI）、聚氧化丙烯二醇（PPG-220）、二羟甲基丙酸（DMPA）、蓖麻油（C0）等为主要原料,合成交联型水性聚氨酯乳液,在此乳液中加入丙烯酰胺、引发剂（KPS）,交联剂（BMA）进行自由基聚合,制备具有IPN结构的聚氨酯-聚丙烯酰胺（PU—PAAm）水凝胶。研究了（PU—PAAm）水凝胶溶胀率（SR）受pH值、温度（T）、交联剂用量等因素的影响。     

三维理想比例导引律的捕获区域分析

在基于球体坐标系内建立的弹-目相对运动方程基础上,对几种典型的比例导引律在三维空间内进行了统一描述。通过引入相对运动的单位角动量,将传统的“捕获区域”描述转化为“捕获长度”的描述,求出了三维空间内理想比例导引律(IPN)的捕获区域,并将之与真比例导引(TPN)、现实真比例导引(RTPN)的捕获区域进行了比较和分析。结果表明,在导航比大于2的情况下对于任何初始攻击布局IPN的捕获条件几乎都成立,而且其捕获区域不受导航比的限制,这和二维平面内的结果相同。     

Tensile Bond Strength of a Highly Cross-Linked Denture Tooth to the Compression-Molded and Injection-Molded Denture Base Polymers

This study compared tensile bond strengths between conventional compression-molded heat (HC)-, auto (AP)-, and microwave-polymerized (MC) poly(methyl methacrylate)-based denture resins and a relatively new injection-molded, microwave-polymerized polyurethane based resin (MI) bonded to a highly cross-linked denture tooth. In the first part of the experiments, denture teeth were used as received. In the second part, they were treated with dichloromethane to see its effect on bonding of conventional denture bases (HCS and APS). Bond strength was tested in tension according to ADA specification No.15. The results showed that the HC group failed cohesively because of higher interface bonding (49.95 MPa) compared with those of the others (AP: 25.41 MPa; MC: 22.06 MPa; MI: 20.02 MPa). The application of dichloromethane improved bond strengths of HCS and APS groups (60.61 and 32.03 MPa, respectively). It was suggested that dichloromethane could be applied on the denture teeth ridge lap area prior to denture base processing to enhance adhesion between the tooth/resin.     

Adhesion Performance and UV-Curing Behaviors of Interpenetrated Structured Pressure Sensitive Adhesives with 3-MPTS for Si-Wafer Dicing Process

Abstract

As Si-wafers, as used in the electronic industry, become thinner and thinner, it is important to investigate the conditions which are suitable for easily peelable acrylic dicing tapes. In the ‘pick-up’ process, the adhesion strength decreased after UV irradiation as a result of polymer network formation. In this study, interpenetrating polymer network (IPN) structured acrylic pressure sensitive adhesives (PSAs) were investigated with two different types of UV irradiation — a steady UV irradiation and a pulsed UV irradiation of 100 mJ/cm². The PSAs binder contained 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA) and 3-methacryloxypropyl trimethoxysilane (3-MPTS). The hexafunctional monomer, dipentaerythritol hexacrylate (DPHA) and 3-methacryloxypropyl trimethoxysilane (3-MPTS) were used as diluent monomers. The adhesion performance as related to the peel strength and the tack properties on the Si-wafer substrates, was examined with increasing UV dose. The effect of UV-curing on the behavior and viscoelastic properties of the ‘pick-up’ acrylic tapes was investigated using Fourier transform infrared — attenuated total reflectance spectroscopy (FTIR–ATR) and an advanced rheometric expansion system (ARES). It is also necessary to consider the contaminants on the Si-wafer substrates left behind after releasing the dicing tapes, because of possible damage to the Si-wafers and subsequent processes. Field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) analysis revealed little residue on the Si-wafer after removing the tapes and after more than the specific level of UV dose.     

A Comparative Study of the Explosion Characteristics of IPN and IPN/JP‐10 Mixtures in Air Aerosols

This article presents a comparison of the explosion characteristics of mixtures of isopropyl nitrate (IPN, (CH₃)₂CHONO₂) and JP‐10 (C₁₀H₁₆, tricycle [5.2.1.0^2,6] decane) in air aerosols. The explosion pressure, flame temperature, maximum rate of pressure rise, maximum rate of temperature rise, and lower flammability limits (LFLs) were measured for two sets of IPN and mixed IPN/JP‐10 in air aerosols at different concentrations and Sauter mean diameters (SMDs) of 19 μm and 34 μm, respectively, and the values were compared with the experimental results of JP‐10/air aerosols with SMDs of 20 μm and 35 μm (from our previous research). Experiments were also performed to study various concentrations at various ignition energies for the IPN/air aerosols and the explosions of binary mixture aerosols with various mass ratios of IPN and JP‐10. The experimental results indicated that for the IPN/air and JP‐10/air aerosols with a mean SMD of ∼34 μm, the maximum peak pressure and maximum peak temperature of the IPN/air aerosols were greater than those of the JP‐10/air aerosols. The maximum rate of pressure rise of the IPN/air aerosols reached a maximum value of 395.3 MPa/s at a mean SMD of ∼34 μm, and the pressure increased more abruptly in the IPN/air aerosols than in the JP‐10/air aerosols. The LFLs of the IPN/air aerosols occurred with a total concentration of 197 g/m³ at a mean SMD of 19 μm and a total concentration of 233 g/m³ at a mean SMD of 34 μm, whereas the LFLs for the JP‐10/air aerosols with SMDs of 20 μm and 35 μm were less than 47 g/m³ and 40 g/m³, respectively. The experimental results presented here also showed that the maximum peak pressure was 1.07 MPa at a binary liquid mass ratio of IPN:JP‐10 (%) of 72 : 28 and a mean SMD of ∼34 μm.     

Dependence of the phase separation process on the relative onset of network formation in simultaneous interpenetrating polymer networks

Morphology development during the synthesis at room temperature of an interpenetrating polyurethane/poly(methyl methacrylate) network was investigated by small-angle X-ray scattering in relation with their relative kinetics of formation, determined by Fourier transform infra red spectroscopy. When the time lag between the onset of the two reactions is short, macroscopic phase separation occurs as the polyurethane network is incompletely formed. However, when the time lag increases, the poly(methyl methacrylate) forms into a more continuous network which limits the growth of phase separation to a close environment.