Crystallization of Polystyrene‐<i>block</i>‐[Syndiotactic Poly(propylene)] Block Copolymers from Confinement to Breakout

Ho, Rong‐Ming; Chung, Tsai-Ming; Tsai, Je Chiang; Kuo, Jing-Chang; Hsiao, Benjamin S.; Šics, Igors

doi:10.1002/marc.200400467

Cited by 34 publications

(32 citation statements)

References 29 publications

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“…In block copolymers containing crystallizable components, the interplay between crystallization and microphase separation strongly influences the structural changes, morphology, properties, and hence applications, of such materials. In addition, other factors, such as melt morphology, crystallization temperature and the degree of crystallinity, will affect the resulting morphology postcrystallization [4][5][6][7][8][9]. The spherulitic structure in semicrystalline block copolymers can affect the ultimate mechanical properties.…”

Section: Introductionmentioning

confidence: 98%

“…The microphase structures of semicrystalline block copolymers are determined by two factors: the thermodynamical incompatibility between constituent blocks and the crystallization behavior of crystallizable blocks [4][5][6][7][8][9]. It is known that the resulting morphology when crystallization occurs depends on whether the block copolymer crystallizes from a microphase-separated melt or from a disordered melt [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

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Hydrogen bonding interactions in poly(ε-caprolactone–dimethyl siloxane–ε-caprolactone)/poly(hydroxyether of bisphenol A) triblock copolymer/homopolymer blends and the effect on crystallization, microphase separation and self-assembly

Salim

Fox

Hanley

2015

European Polymer Journal

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Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Hydrogen bonding interactions in poly(ε-caprolactone–dimethyl siloxane–ε-caprolactone)/poly(hydroxyether of bisphenol A) triblock copolymer/homopolymer blends and the effect on crystallization, microphase separation and self-assembly

Salim

Fox

Hanley

2015

European Polymer Journal

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“…This fact is strongly supported by the DSC results showing that the crystallinity of hPNB blocks for B61 $ B79 is significantly larger than that for B12 $ B49. 9,25,27 In summary, Figure 2 indicates that B12 $ B49 have T g ) T c Ã to result in confined crystallization, whereas B61 $ B79 have T c Ã $ T g , and the crystallization of hPNB blocks at T c Ã will be considerably influenced by T g of hPMTF blocks. This means that the resulting morphology and eventually the melting behavior depend significantly on the crystallization condition such as the crystallization time t c at T c Ã .…”

Section: Thermal Characterization Of Hpnb-b-hpmtfmentioning

confidence: 99%

“…[25][26][27] Ho et al, for example, investigated the morphology of synpolypropylene-block-polystyrene (sPP-b-PS), 27 where T g of amorphous PS blocks partially overlapped with the T c range of crystalline sPP blocks. They observed confined or break-out crystallization according to T c they used.…”

mentioning

confidence: 99%

Excess X-ray Scattering Observed at Low Angles during Melting of Crystalline-Amorphous Diblock Copolymers

Tonami

Nojima

Honda³

et al. 2009

Polym. J.

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The heating process of a series of new crystalline-amorphous diblock copolymers, hydrogenated polynorbornene-blockhydrogenated poly(1,4-methano-1,4,4a,9a-tetrahydrofluorene) (hPNB-b-hPMTF), has been investigated using time-resolved small-angle X-ray scattering with synchrotron radiation. When the crystalline hPNB block was the major component in hPNB-b-hPMTF, the crystallization temperature of hPNB blocks at the maximum rate T c Ã (i.e., the peak temperature of DSC exotherms during cooling at À5 C/min) was found to be nearly the same to the glass transition temperature T g of amorphous hPMTF blocks. For these copolymers, the excess upturn scattering at low angles was transiently observed during the melting of hPNB blocks, which depended significantly on the composition and the thermal history applied to hPNB-b-hPMTF before heating. The crystallized lamellar morphology (i.e., an alternating structure consisting of hPNB lamellar crystals and amorphous hPNB + hPMTF layers), which had been gradually transformed from the molten microdomain structure by the crystallization of hPNB blocks, was responsible for the emergence of this scattering, because the excess X-ray intensity was proportional to the volume fraction of the crystallized lamellar morphology existing in the system. We discussed the possible origin of this excess scattering by considering the morphological change during melting.KEY WORDS: Crystalline-Amorphous Diblock Copolymer / Melting Process / Synchrotron SAXS / Excess X-ray Scattering /The morphology formation of crystalline-amorphous diblock copolymers is complicated depending on the relative position of the order-disorder transition temperature of block copolymers T ODT , the crystallization temperature T c of crystalline blocks, and the glass transition temperature T g of amorphous blocks.1-3 When T ODT > T g > T c , the molten microdomain structure is frozen at T c and eventually crystallization is effectively confined within this structure (confined crystallization), resulting in a crystallized microdomain structure.4-14 When T ODT > T c > T g , on the other hand, the microdomain structure is completely replaced with a crystallized lamellar morphology, an alternating structure consisting of lamellar crystals and amorphous layers, if the total molecular weight and the interaction between two blocks are not large enough (break-out crystallization).15-24 However, there are limited studies on the morphology formation of crystalline-amorphous diblocks with T ODT > T g $ T c . [25][26][27] Ho et al., for example, investigated the morphology of synpolypropylene-block-polystyrene (sPP-b-PS), 27 where T g of amorphous PS blocks partially overlapped with the T c range of crystalline sPP blocks. They observed confined or break-out crystallization according to T c they used. Thus, we can expect that the crystallization behavior and resulting morphology of crystalline-amorphous diblocks with T g $ T c depend significantly on T c and also the crystallization time t c , because the mobility of polymer chains is...

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“…Structure formation in block copolymers has been extensively studied from both theoretical and experimental view points [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . In block copolymers composed of only amorphous components, the driving force for structure formation is the incompatibility between the block chains, characterized by c N t , where c is the Flory interaction parameter and N t is the total number of segments in the copolymer.…”

Section: Introductionmentioning

confidence: 99%

Structure Formation and Crystallization Behavior of Ethylene-Isoprene Block Copolymers and Their Blends with Corresponding Homopolymers

et al. 2008

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Time-resolved simultaneous synchrotron small-angle X-ray scattering and differential scanning calorimetry experiments have been performed on crystallization of polyethylene-polyisoprene diblock copolymers (HEI or LEI) and their blends with corresponding homopolymers, polyethylene (PE) and polyisoprene (PIp). For the neat block copolymer having a 50 wt% of the crystalline component, preexisting microphase separation structure in the melt was kept at high and low crystallization temperatures T c (T c Ն94°C and T c Ͻ60°C), while disrupted at intermediate T c (60°CՅT c Ͻ94°C). This complex behavior was interpreted by combination of two mechanisms. The behavior in the crystallization below 94°C was attributed to the competition between the crystallization and chain diffusion rates, that is, the fast crystallization rate at lower T c makes it difficult to rearrange the phase structure in the melt. On the other hand, at a higher T c (Ն94°C), the preservation of the microphase separation structure was explained by a small degree of crystallinity due to the ethyl branch of polyethylene (hydrogenated poly(butadiene)). For HEI/PE blends, crystallization behavior was the simple superposition of those for HEI and PE, while, for HEI/PIp with a small composition of PE, suppression of crystallinity was observed. Crystallization kinetics in the neat block copolymer and all the blends was not so different from that in the PE homopolymer.Keywords Microphase separation, Structure formation, Crystallization, Polyethylene-polyisoprene block copolymer. Regular Articlee-Journal of Soft Materials, Vol. 4, pp. 12-22 (2008) amorphous component T g A 19,20) . When crystallization temperature T c is lower than T g A , that is, the amorphous component is in glassy state at T c , microphase separation structure in the melt is usually maintained in crystallization, because the microphase separation structure is frozen by the glassy domains 19,21,22) . On the other hand, when T c is higher than T g A , it has been reported that structural change in crystallization depends on the segregation strength between components (cN t ). Quiram et al. explored the crystallization of a high molecular weight polyethylene-poly(3-methyl-1-butene) block copolymer (strongly segregated system) with a polyethylene weight fraction f E of 0.27, and found that polyethylene crystallized within preexisting cylindrical microdomains 23,24) . Nojima et al. 25) also investigated a crystallization process of crystalline-rubbery amorphous block copolymers for poly(e-caprolactone)-polybutadiene (weakly segregated system) through a time-resolved smallangle X-ray scattering (SAXS) technique using synchrotron radiation as a light source, and observed that a preexisting SAXS peak from the microphase separation disappeared with development of a new peak originating from the long period of crystal lamellae. Furthermore, we have reported that a high molecular weight poly(ethylene glycol)-poly(butadiene) block copolymer (PEG-PBD), which is relatively strongly segrega...

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Crystallization of Polystyrene‐block‐[Syndiotactic Poly(propylene)] Block Copolymers from Confinement to Breakout

Cited by 34 publications

References 29 publications

Hydrogen bonding interactions in poly(ε-caprolactone–dimethyl siloxane–ε-caprolactone)/poly(hydroxyether of bisphenol A) triblock copolymer/homopolymer blends and the effect on crystallization, microphase separation and self-assembly

Hydrogen bonding interactions in poly(ε-caprolactone–dimethyl siloxane–ε-caprolactone)/poly(hydroxyether of bisphenol A) triblock copolymer/homopolymer blends and the effect on crystallization, microphase separation and self-assembly

Excess X-ray Scattering Observed at Low Angles during Melting of Crystalline-Amorphous Diblock Copolymers

Structure Formation and Crystallization Behavior of Ethylene-Isoprene Block Copolymers and Their Blends with Corresponding Homopolymers

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