Poly Ester Imide Research Articles

POLYESTERIMIDE-MODIFIED BISMALEIMIDE RESINS. I. EFFECT OF POLYESTERIMI DE CONTENT

ABSTRACT A novel polyesterimide (PEsI-M) was used to improve toughness of bismaleimide (BMI) resin composed of bis(4-maleimidediphenyl) methane (BDM) and O,O′-diallyl bisphenol A (DBA). Morphologies of modified resins changed from spherical particles to inverted phase structures, depending on PEsI-M's content based on the observation of scanning electronic microscopy (SEM). PEsI-M was an effective morphology modifier so that loading of 12 pbw resulted in a diverted phase structure. Dynamic mechanical analysis (DMA), rheometrics mechanical spectroscopy (RMS) and differential scanning calorimetry (DSC) were respectively used to investigate the dynamic mechanical behavior, and the gelation time and the curing extent of unmodified and modified BMI resins. The fairly uniform morphology in 15 pbw PEsI-M modified system cured at 180°C suggests that the phase separation might take place via a spinodal decomposition mechanism. The fracture energy (G IC ) increased with the increase of PEsI-M content in the modified system. G IC of 15 pbw PEsI-M modified system was 0.63 times larger than that of the unmodified BMI resin.

STUDIES ON PHASE SEPARATION OF POLYESTERIMIDE-MODIFIED EPOXY RESIN. II. EFFECT OF CURING TEMPERATURE ON PHASE SEPARATION AND ADHESIVE PROPERTY

A sort of polyesterimide (PEsI) was used as a toughening agent in the modification of epoxy resin/anhydride system. The reaction-induced phase separation in amorphous thermoplastic-modified epoxy system was observed in situ by means of time-resolved light scattering (TRLS) and advanced rheometric expansion system (ARES) at different curing temperature. TRLS displayed that the phase separation of the blend system followed a spinodial decomposition mechanism at different curing temperature. The increase of curing temperature accelerated curing reaction and the increase of the blend viscosity prevented phase separation from proceeding. Results of TRLS and ARES showed that the phase structure fixation was pinned up by blend viscosity at the early stage of curing reaction, rather than by gelification at the late stage of curing reaction. All the experiments, including scanning electron microscopy (SEM), suggested that low curing temperature was beneficial to the formation of longer interdomain distance of the epoxy-in-rich phase in the blend and to the improvement of adhesive property of the blend.

Effect of a crosslinking monomer on the course of curing of unsaturated polyesterimide (PEI) resins

Effect of a crosslinking monomer on the course of curing of unsaturated polyesterimide (PEI) resins

Studies on the synthesis and properties of soluble homo‐ and copolyester–imide derived from imide–diacid

AbstractA series of polyester–imides was prepared from diacid (imid–diacid [M1–M4] or a mixture of imide–diacid and terephthalic acid [TPA]) and bisphenol A in the presence of diphenyl chlorophosphate (DPCP) and pyridine as a direct condensation agent. The inherent viscosites of homo‐ and copolyester–imides were in the range of 0.39–0.58 dL/g. Almost all these homo‐ and copolyester–imides were completely soluble in N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylacetamide (DMAC), dimethylformamide (DMF), and m‐cresol. The thermal properties of homo‐ and copolyester–imides were examined by DSC and TGA. These copolyester–imides had glass transition temperatures in the range of 95–240°C and a 5% weight loss was observed in the range of 354–465°C. © 1995 John Wiley & Sons, Inc.

Condensation polymerization of multifunctional monomers and properties of related polyester resins. II. Thermal properties of polyester—imide varnishes

Polyester—imide prepolymers containing synthesized N,N′-bis(hydroxyethyl)pyromellitic diimide (PMDI) or N,N′-bis(hydroxyethyl)-3,3′-4,4′-benzophenone tetracarboxylic diimide (BTDI) were synthesized under conditions previously reported. One-component varnishes were obtained by mixing the synthesized prepolymers with commercial Desmodur CT-stable. Thermal behavior of these varnishes was investigated using thermogravimetric analysis. Activation energy of cured film, which was a polyester—imide varnish, was determined by using a multiple heating rate method. Polyester—imides coated copper wires were characterized, and were found to be acceptable, according to the specification of Japanese Industrial Standard (JIS-C-3214).

Peculiarities of supermolecular structure of polyimides and polyester imides

AbstractSupermolecular structures of fourteen heterocyclic thermally stable polymers of the polyimide (PI) and polyesterimide (PEI) class have been investigated by X‐ray scattering, optical, dilatometric and thermomechanical methods. Quasi‐crystalline structure of these polymers in the initial amorphous state of poly(amic acid) and poly(ester amic acid) and also after chemical imidization has been revealed. The quasi‐crystalline structure is characterized by a biaxial polarizability ellipsoid with a negative sign. This is indicated by distinct conoscopic figures recorded with a polarizing microscope. The effect of the number of oxyphenylene groups on the crystallizability of PI and PEI was investigated. For PEI the effect of self‐orientation of macromolecules induced by conformational transition was observed. Discrete small‐angle x‐ray scattering pattern (a long period) was also revealed for PEI. The appearance of long periods is caused by polymorphism of PEI uniquely determined for one of its types (PEI‐II). X‐ray scattering data confirmed by calculations of the lattice energy show that dianhydride pyromellitimide chain portion is the element determining the crystalline structure of PI. The structure is determined by van der Waals' forces and obeys the principle of dense packing. This leads to the appearance of layer structure with alternating layers of diamine and dianhydride portions. It was found that, depending on the rigidity of the diamine portion, PI and PEI exhibit different abilities of forming axial‐planar or axial textures in nonoriented films.

Unstaurated polyester imides

AbstractImide‐containing polyesters have been prepared by melt polycondensation of propylene glycol with saturated and/or unsaturated diacids and imide diacids. These imide diacids have been synthesized from trimellitic anhydride and aliphatic ω‐amino acids, and differ from each other in the number of CH2groups.When mixtures of styrene and the unsaturated polyester imides are activated by peroxidic type initiators, crosslinked products are obtained, the properties of which can be related to the proportion of imide rings and the length of the aliphatic chain in its chemical structure.

The morphology and optical properties of polyimides and polyestermides

Results are presented of a microscopical investigation of the structure and optical properties of some polyamido-acids (PAAs), polyesteramidoacids (PEAAs) and of the corresponding polyimides (PIs) and polyester imides (PEIs). It was found that the structure of PIs and PEIs formed at high temperatures is a fairly complete copy (on the optical level) of the structure of the original PAAs and PEAAs (amorphous according to X-ray analysis). The components of the polarizability tensor of the monomer unit of a PAA and the corresponding PI is calculated according to the valence-optical additivity principle. It is shown that conoscopic investigation enables the imidization of PAAs and PEAAs, and the crystallization of PIs and PEIs to be monitored. It also permits determination of the position of the axes of the macromolecules (in relation to the surface of the film) and of the conformation of the monomer unit during the phase transition.

Effect of the deformation of the film -substrate system on the physicochemical properties of films and their adhesion strength

It was shown that the mechanism of deformation of films of rigid crosslinked polymers (polyester, polyester imide, polyester cyanurate) is appreciably different from the deformation mechanism of free films: a forced highly elastic deformation takes place, sometimes even at an early stage, while the free films deform reversibly up to rupture. Explanations have been suggested for the characteristic features of deformation of films studied on a substrate. The forced highly elastic deformation process is related to the effect of orienting reinforcement of films. An increase in the adhesion strength in the film-substrate system during the deformation has been shown, and an explanation of this effect has been proposed.

The structure of oriented crystalline polyester imides

X-ray structural analysis and infrared spectroscopy were the basis of investigation of the crystalline structure of two oriented polyester imides (PEI-II and PEI-III) prepared by chemical and thermal imidization of poly(acid)amido esters (PAAE) based on paraphenylene-bis-trimellitatedianhydride and aromatic diamines, namely the 4,4′-diaminodiphenyl and bis-4-aminophenyl esters of hydroquinone. It is shown that, as a result of stretching (150–250% extensions) and further heat treatment (370–390°), highly oriented crystalline structures appear in the samples. the space cell of PEI-II is monoclinic ( a = 5·56; b=7·94; c=58 A ̊ ; γ=86° ). The parameters of the rhombic cell proposed for PEI-III are: a=5·64; b=8·05; c=34·5 A ̊ . The dichroism of the absorption bands in the IR polarized spectra of PEI-II and PEI-III provided a basis for calculating the direction of the transition moments of a number of vibrations relative to the molecular axis. The conformational structure of the macromolecules is proposed for the polyester imides in the light of experimental results.

The Syntheses of Polyamide-Imides and Polyester-Imides from 1, 4, 5-Naphthalene Tricarboxylic Anhydride

Four bisimide carbexylic acids (BICA) were prepared from 1, 4, 5-naphthalene tricarboxylic anhydride and aromatie diamines. Polyamide-imides (PAI) and polyester-imides (PEI) were synthesized by the acidolysis of these BICA with diacetyl derivatives of aromatic diamines and diols. Reduced viscosities of PAI and PEI were in the ranges of O.17. vO.50 and O.20. Nb. O.40, respectively, in O.5% conc. H2SO4 solution at 30 C.