The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A series of aliphatic acid esters of (2-hydroxypropyl) cellulose (C n PC) were synthesized via the esterification of aliphatic acid chloride and (2-hydroxypropyl) cellulose (HPC). The liquid crystalline (LC) phases and transitions were investigated using differential scanning calorimetry, wide-angle X-ray diffraction (WAXD), and polarized light microscope (PLM) techniques. This series of C...
Polyimide (PI)–polyethylene oxide (PEO) block copolymers have a wide variety of applications in microelectronics, since PI–PEO films exhibit a high degree of thermal and chemical stability. The polymers consist of short, rigid rod T-shaped PI segments, alternating with flexible, PEO coil segments. The highly incompatible PI rods and PEO coils should phase-separate, especially in the presence of lithium...
A series of newly designed polyimides, composed of aromatic polyimide backbones and methylene side chains with terminal 4-cyanobiphenyl groups, were synthesized based on the polycondensation of 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA) with 2,2′-bis{ω-[4-(4-cyanophenyl)phenyoxy-n-alkoxycarbonyl]}-4,4′-biphenyl diamine (nCBBP, where n is the number of methylene units in the side chains)...
Two new asymmetric odd-numbered main-chain liquid crystalline (LC) polyesters (BPE-Cn) were synthesized through the condensation polymerization of A–B type asymmetric α,ω-carboxylic acid–hydroxyl terminated monomers with odd-numbers of methylene units in the spacers (BPCA-Cn-PmOH, where n=7 and 9). The phase behaviors and structures of these odd-numbered BPE-Cn samples were characterized using the...
Micro-banded textures developed from thin films of a main-chain thermotropic liquid crystalline chloro-poly(aryl ether ketone) in the melt were investigated using transmission electron microscopy (TEM), selective area electron diffraction, and atomic force microscopy techniques. The micro-banded textures were formed in the copolymer thin films after annealing at temperatures between 320 and 330 ...
Continuous zone-drawing and zone-annealing processes have been utilized to probe improvements in mechanical performance of melt-spun high acrylonitrile copolymer fibers (AMLON ). The as-spun fibers were zone-drawn at different ratios in a narrow temperature range of 100-105 o C and then zone-annealed. As a result of these processes, the fibers show substantial increases in tensile strength...
Dianhydrides of specific molecular architecture was designed and synthesized based on 2,2′-disubstituted 4,4′,5,5′-biphenyltetracarboxylic dianhydrides (2,2′-disubstituted BPDAs). Eight dianhydrides were polymerized with two 4,4′-diamino-2,2′-disubstituted biphenyl diamines (trifluoromethyl disubstituted groups, or PFMB, and methyl disubstituted groups, or DMB) to obtain two series of PFMB- and DMB-based...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.