Molecular order and phase transitions in smectic poly(ester imide)s based on trimellitimide

Wutz, Christoph

doi:10.1016/s0032-3861(99)00561-3

Cited by 15 publications

(7 citation statements)

References 34 publications

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“…The non-substituted TAHQ/4,4 0 -ODA system showed a high T g at 340 C with a broad transition around 210 C in the DMTA curve (this lower temperature transition will be discussed later). The results revealed that the effect of the methoxy and methyl substituents caused a certain degree of T g increase (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) C) as shown in Table III. This can be interpreted in terms of suppressed internal rotation of the central hydroquinone moiety by some steric hindrance due to the present small substituents.…”

Section: Molecular Designmentioning

confidence: 91%

“…We previously proposed a hybrid material between PIs and polyesters, namely, poly(ester imide)s (PEsIs) as a new material for FCCL and our results revealed that some PEsIs derived from TAHQ with APAB and a minor fraction of a flexible diamine as a comonomers achieved a very low extent of water absorption, a low CTE value approximate to copper foil, and excellent flexibility (film toughness) at the same time. 19 Poly(ester imide)s have been so far studied only in the limited view points of film basic properties such as thermal stability and solubility, and mechanical properties, [20][21][22][23][24][25][26] mechanical properties of fibers, 27 liquid crystallinity [28][29][30] without any attentions toward FCCL applications. Many of the previously reported poly(ester imide)s were synthesized via the direct polymerization of polyester from imide-containing diols with dicarboxylic acids without the pathway of thermal imidization which plays a great role for spontaneous in-plane orientation.…”

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confidence: 99%

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Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Hasegawa

Tsujimura

Koseki

et al. 2007

Polym J

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The film properties of a variety of poly(ester imide)s (PEsIs) were evaluated for development of a novel high temperature base film in flexible printed circuit (FPC) boards. In this work, three types of PEsI systems were systematically prepared from the following combinations of monomers: (1) ester-containing tetracarboxylic dianhydrides: hydroquinone bis(trimellitate anhydride) (TAHQ), methyl-substituted TAHQ (M-TAHQ), and methoxy-substituted TAHQ (MeO-TAHQ) with common diamines such as p-phenylenediamine (PDA), (2) common tetracarboxylic dianhydrides such as pyromellitic dianhydride (PMDA) with ester-containing diamines: 4-aminophenyl-4 0 -aminophenylbenzoate (APAB) and methyl-substituted APAB (ATAB), and (3) the TAHQ series with the APAB series. The effects of the substituents on the PEsI film properties and polymerizability were also discussed in this work. The ester-containing monomers used in this work (TAHQ series and the APAB series) were all highly reactive and led to PEsAAs possessing high inherent viscosities ranging 1.09-9.33 dL/g. The incorporation of methyl and methoxy substituents into rigid TAHQ-based PEsI systems caused no significant decrease in T g but allowed molecular motions above the T g s. In some cases, these substituents, in particular, the methoxy group contributed to a significant decrease in water absorption without sacrificing other target properties. For practical FPC application, a flexible diamine was copolymerized into the highly esterified rigid PEsI systems derived from the TAHQ series with the APAB series. One of the PEsI copolymers obtained achieved excellent combined properties: a low CTE (17.8 ppm/K) completely consistent with that of copper foil as a conductive layer, considerably low water absorption (0.47 wt %), a high T g exceeding 360 C, and improved toughness (elongation at break > 40%). Polyimides (PIs) have been widely utilized in a variety of micro-and optoelectronic applications such as flexible printed circuit boards (FPC), chip on film (COF) assembling system, tape automated bonding tapes (TAB), buffer-coating films and interlayer dielectrics for LSI chips, high temperature adhesives, light wave guides for their combined excellent properties, i.e., high glass transition temperatures (T g ), high resistance to chemicals and radiation, relatively low dielectric constants, and good mechanical properties.1-10 The advantages of PI materials are considerably high purity (extremely low contents of metal contaminations and residual monomers and solvents) in the resins, simple fabrication processes, and the ease of structural modifications through copolymerization using various commercially available monomers.FPC, TAB, and COF are fabricated from PI film/Cu foil laminates (flexible copper clad laminates, FCCL or CCL). Adhesive-free FCCL has an advantage in the view point of dimensional stability against heat cycles compared to that using thermally less stable conventional adhesives. This type of FCCL is usually produced by the casting method (thermal imidization after s...

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Section: Molecular Designmentioning

confidence: 91%

mentioning

confidence: 99%

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Hasegawa

Tsujimura

Koseki

et al. 2007

Polym J

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“…Liquid crystalline (LC) thermosets have been extensively investigated in many research groups due to their excellent properties, such as high-strength, high modulus, a relatively low coefficient of thermal expansion and dimensional stability. [1][2][3][4] Liquid crystalline epoxy resin (LCER) is an important thermosetting polymers, and have widely applied in numbers of scopes, such as electronics, advanced composites, nonlinear optics. [5][6][7][8] At present, many investigators have reported the synthesis, characterization of texture, phase behavior, and the curing kinetics of LCER containing hydroquinone or bisphenol, etc.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of the two novel liquid crystalline epoxy resins based on bisphenol‐s mesogen

Huo¹,

Gao²,

Du³

et al. 2008

J of Applied Polymer Sci

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Two novel liquid crystalline epoxy resins (LCER) based on bisphenol-S mesogen, 4,4 0 -Bis-(2,3-epoxypropyloxy)-sulfonyl bis(1,4-phenylene) (p-BEPSBP) and sulfonyl bis(4,1-phenylene) bis[4-(2,3-epoxypropyloxy)benzoate] (p-SBPEPB), were synthesized. Their liquid crystalline behavior and structure were characterized by Fourier transmittance infrared ray (FTIR), differential scanning calorimetry (DSC), 1 HNMR, polarized optical microscopy (POM) and X-ray diffraction (XRD). The results show that p-BEPSBP is a kind of thermotropic liquid crystal and has a smectic mesophase with a melting point (T m ) at 165 C; the p-SBPEPB is a kind of nematic mesophase with the temperature range of 155-302 C from the T m to the clearing point T i . The curing behaviors and texture of the liquid crystalline epoxy resins with 4,4 0 -diaminodiphenyl ether (DDE) were also studied by DSC and some kinetic parameters were evaluated according to the Ozawa's method. The dynamic mechanical properties of curing products were also investigated by torsional braid analysis (TBA), and the results suggest that the dynamic mechanical loss peak temperature (T p ) of p-BEPSBP/DDE and p-SBPEPB/DDE is 120 and 130 C, respectively.

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“…This difference in kinetics can be quantified by estimating the Avrami exponent for the first exothermic peak using the following equation derived from the so-called Avrami equation: [17][18][19][20] ln…”

Section: Kinetics Of Liquid Crystallizationmentioning

confidence: 99%

Two‐Step Smectic CA Phase Formation from Isotropic Liquid upon Supercooling in Main‐Chain Liquid‐Crystalline BB‐5(1‐Me) Polyester

Ishige

Tokita

Funaoka

et al. 2010

Macro Chemistry & Physics

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The mesophase formation process of a main‐chain BB‐5(1‐Me) polyester in the supercooled isotropic‐liquid state has been studied using DSC, WAXD, and optical microscopy. The supercooled isotropic liquid follows two different SmCA formation processes. Above 85 °C, it forms the expected SmCA phase. Below, it yields a metastable SmA phase that displays a layer spacing almost twice the one of the SmCA phase. The SmA phase develops from a homogeneous nucleation followed by 3D growth and thereafter transforms to the SmCA phase. This two‐step SmCA formation involves a change in polymer chain configuration: first, the chains are folded in each two units to form the SmA phase and then they stretch to achieve the characteristic zigzag arrangement of the mesogens in the SmCA phase.

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Molecular order and phase transitions in smectic poly(ester imide)s based on trimellitimide

Cited by 15 publications

References 34 publications

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Poly(ester imide)s Possessing Low CTE and Low Water Absorption (II). Effect of Substituents

Synthesis and characterization of the two novel liquid crystalline epoxy resins based on bisphenol‐s mesogen

Two‐Step Smectic CA Phase Formation from Isotropic Liquid upon Supercooling in Main‐Chain Liquid‐Crystalline BB‐5(1‐Me) Polyester

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