Preparation of Poly(<i>p</i>-oxybenzoyl) Microspheres Having Needlelike Crystals on the Surface

Kimura, Kunio; Kohama, Shin Ichiro; Kondoh, Satomi; Yamashita, Yuhiko; Uchida, Tetsuya; Oohazama, Takeshi; Sakaguchi, Yoshimitsu

doi:10.1021/ma035672z

Cited by 16 publications

(16 citation statements)

References 26 publications

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“…82,83 The polymerization of ABA and 3,5-diacetoxybenzoic acid (DABA) at a molar ratio of DABA in the feed of 0.05-0.20 yielded the microspheres having needlelike crystals on the surface as shown in Figure 9b. The diameter of the microspheres was in the range of 3.4-1.6 mm and the length of the needle-like crystals was 3.2-0.3 mm.…”

Section: Reaction-induced Liquid-liquid Phase Separationmentioning

confidence: 99%

Morphology Control of Aromatic Polymers in Concert with Polymerization

Kimura

Kohama

Yamazaki

2006

Polym J

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ABSTRACT:Morphology control methods of aromatic polymers in concert with polymerization reaction are described in this review. Many attractive methods have been developed including reaction-induced phase separation of oligomers, epitaxial polymerization, shear-induced chain orientation during gelation, template-based polymerization, suspension polycondensation, solid-state polycondensation and liquid-liquid interfacial precipitation and so on. Among them, the reaction-induced phase separation of oligomers, in which there are two modes of crystallization and liquidliquid phase separation, possess practically high potentiality to create novel polymer materials since it can control not only the morphology but also the molecular chain orientation. Ultimate goal is the embodiment of the nature system in a flask, that is, the control of the materials from primary structures to super structures. The morphology control methods by using polymerization reaction afford the valuable methodology for the three-dimensional structure architecture.[doi:10.1295/polymj.PJ2006083] KEY WORDS Morphology / Phase Separation / Oligomer / Whisker / Microsphere / Epitaxy / Aromatic Polymer / Morphology of polymer materials is of great importance as well as the molecular chain orientation for the creation of new functional and high-performance materials possessing essential properties predicted from their molecular structures. From the both aspects of molecular chain orientation and morphology, one of the ideal materials is a needle-like single crystal of extended molecular chains called polymer whisker. Especially, wide variety of polymeric nanomaterials is required for supporting nanotechnology and the more precise controls are rapidly necessitated in these days. Hence, the demand for the morphology control method increases significantly. Usually, extended molecular chain crystals are difficult to obtain by conventional processing methods and the special processing techniques have been developed thus far.1 There exists another stream for the development of extended molecular chain crystals by means of crystallization during polymerization. The needle-like crystals of both flexible and rigid polymers have been obtained by the solid-state polymerization of the monomers and the polymerization in the solution. Examples of the former polymerization have included oxacyclobutanes such as 1,3,5-trioxane, 2,3 diolefins undergoing four-center type photopolymerization 4,5 and monomers with conjugated triple bonds such as substituted diacetylenes.6,7 On the other hand, the first polymer whisker was obtained by the cationic ring-opening polymerization of 1,3,5-trioxane. [8][9][10] The obtained polyoxymethylene whiskers were 1-2 mm in width and 10-50 mm in length. The molecular chains aligned along the long axis of the whisker. They were brought into practical uses with its unique morphology and good mechanical properties.11,12 However, the polyoxymethylene whisker has a melting temperature at 180 C and the low melting temperature limits the broader c...

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Section: Reaction-induced Liquid-liquid Phase Separationmentioning

confidence: 99%

Morphology Control of Aromatic Polymers in Concert with Polymerization

Kimura

Kohama

Yamazaki

2006

Polym J

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“…BPB was converted into BPBA during the purification by recrystallization as confirmed by IR spectroscopy. p-Hexyloxybenzoic acid (HOBA), 4-(4-hexyloxybenzoyloxy)benzoic acid (HBBA) and p-hexyloxyphenol (HOPH) were synthesized according to the previously reported procedures [16,19]. 4-(4-Hexyloxyphenoxycarbonyl)phenol (HPCP) was synthesized according to the previously reported procedure [24].…”

Section: Methodsmentioning

confidence: 99%

“…Based on the previous studies [16,19], it might be expected that oligomers end-capped by monofunctional compounds are precipitated to form the crystals, but the molecular weight increases by further polymerization in the crystals with the elimination of monofunctional compounds by ester exchange reaction as shown in Scheme 3. In order to prove the mechanism for the increase in the molecular weight under nonstoichiometric condition, the change in the yield and the DP n of the POB precipitates were examined in the course of the polymerization at c of 20 mol%.…”

Section: Polymerization Behavior Under Non-stoichiometric Conditionmentioning

confidence: 98%

Preparation of aromatic polyesters by direct polymerization in the presence of boronic anhydride under non-stoichiometric condition

Kihara

Sakakiyama

Yamazaki

et al. 2015

Polymer

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“…15,16 When the polymerization is performed in the solvent which is good to monomers and poor to polymers, phase separation is induced by the increase in the molecular weight of oligomers formed in the solution. When the crystallization occurs, the oligomers are precipitated to form the crystals and the following polymerization proceeds in the precipitated crystals with maintaining the morphology.…”

Section: Introductionmentioning

confidence: 99%

“…The morphology is built by means of the phase separation during polymerization, and therefore this method is no longer limited by the intractability of polymers. With respect to the spherical morphology, microspheres 15 and those having needle-like crystals 16 have also been prepared by the reaction-induced liquid-liquid phase separation. Many of the high-performance polymers are usually synthesized by the polycondensation reaction that proceeds with eliminating small molecules.…”

Section: Introductionmentioning

confidence: 99%

Hollow spheres of aromatic polyamide prepared by reaction‐induced phase separation

Fujitsu

Nakayama²,

Uchida

et al. 2012

J. Polym. Sci. A Polym. Chem.

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Hollow spheres of aromatic polyamide are obtained by the reaction-induced phase separation during polymerization of 5-hydroxyisophthalic acid and 1,4-phenylene diamine in an aromatic solvent at a concentration of 1-2% at 320 C without stirring. The hollow sphere has a dimple hole and the diameters of the hollow spheres are 3-4 lm. The droplets are initially generated via liquid-liquid phase separation and then rigid crosslinked network structure formed the rigid skin layer on the surface of the droplets. The solidification of the droplets occurred owing to the further polymerization in them with maintaining the morphology to form the hollow spheres. The hollow spheres exhibit outstanding thermal stability. 14 Although the rigid polyimides exhibit poor tractability, hollow spheres can be prepared using the soluble precursor poly(amic acid)s. However, many of other aromatic polymers show neither fusibility nor solubility owing to their rigidity and it is too difficult to control the morphology precisely.

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Preparation of Poly(p-oxybenzoyl) Microspheres Having Needlelike Crystals on the Surface

Cited by 16 publications

References 26 publications

Morphology Control of Aromatic Polymers in Concert with Polymerization

Morphology Control of Aromatic Polymers in Concert with Polymerization

Preparation of aromatic polyesters by direct polymerization in the presence of boronic anhydride under non-stoichiometric condition

Hollow spheres of aromatic polyamide prepared by reaction‐induced phase separation

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