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The crystalline morphology of a double crystalline polyethylene- block -poly(β-propiolactone) diblock copolymer (PE- b -PPL) was examined using synchrotron small-angle X-ray scattering (SR-SAXS), where the PPL block crystallized into δ- or β-form according to the thermal history during sample preparation. Furthermore, the isothermal crystallization process of PE- b -PPL was pursued using simultaneous time-resolved SR-SAXS and wide-angle X-ray diffraction (SR-WAXD). The crystallization behavior of δPPL blocks (i.e., PPL blocks to crystallize into δ-form) was similar to that of PE blocks without any detectable induction time, so simultaneous crystallization of PE and δPPL blocks was observed on quenching from a lamellar microdomain structure (LMS), yielding a largely distorted LMS (with the standard deviation of each lamella thickness ∼ 36%). On the other hand, the βPPL blocks (i.e., PPL blocks to crystallize into β-form) started to crystallize after an appreciable induction time, showing sequential crystallization (i.e., advance crystallization of PE blocks and subsequent crystallization of βPPL blocks) to form a slightly distorted LMS (18%). Consequently, the final crystalline morphology was significantly different depending on the crystal structure of PPL blocks, though the crystallization started from an identical LMS. The crystallization mechanism of PE- b -PPL was discussed by considering the difference in crystallization kinetics between PE blocks and PPL (δPPL or βPPL) blocks.

The crystalline morphology formed in binary blends of poly(e-caprolactone)- block -polyethylene (PCL- b -PE) copolymers and PCL homopolymers has been examined using synchrotron small-angle X-ray scattering (SR-SAXS) and differential scanning calorimetry (DSC) as a function of the homopolymer fraction in the blend. The PE block crystallized first on quenching from a lamellar microdomain structure to set a hard lamellar morphology (PE lamellar morphology) in the blend, followed by the crystallization of PCL chains ( i.e ., PCL homopolymers + PCL blocks). Two binary blends were studied by considering the miscible state of PCL homopolymers in the microdomain structure: when the PCL homopolymers were uniformly mixed with PCL blocks, they formed a mixed crystal. When the PCL homopolymers were localized between PCL blocks in the microdomain structure, DSC results suggested the possible formation of separate PCL crystals in the PE lamellar morphology. The effect of the advance crystallization of PE blocks on the subsequent crystallization of PCL chains was discussed as compared with the crystalline morphology formed in PCL- block -polybutadiene copolymer/PCL homopolymer blends, where the crystallization of PCL chains started directly from a microdomain structure without forming the hard lamellar morphology.

Super-hydrophobic surface has been prepared onto biodegradable polymer by a combination of transcribing microscopic structure of a water-repellent leaf and a chemical treatment. An aroid leaf has been chosen for the preparation of the super-hydrophobic surface since the leaf has concavity microscopic structure, which is easy to handle for a material use. The microscopic pattern was transcribed onto poly(e-caprolactone) (PCL) sheet by using replica method, then it was further treated by soaking in a mixture of acetone/methanol solution. The resultant PCL having the microscopic concavity pattern showed high water contact angle of 148° and also showed antibacterial property for filamentous fungi.

The anisotropy in mechanical properties of forged isotactic polypropylene (iPP) has been investigated by microhardness indentation and Izod impact tests. The results are important, since the major changes in these properties that have been found can influence the growing number of applications where iPP is indented or impacted in use. The iPP had a molecular weight of 2.9 × 10 5 and an initial fraction of 64% α-crystal. For these samples forged at 140°C (resulting in α-crystal only plus amorphous), the indentation hardness perpendicular to the plane direction, H (⊥), slightly increased with draw. The hardness tested parallel to the film surface, H (/ t |), decreased rapidly with draw. For the sample forged at 50°C (containing draw-generated smectic), both H (/ t |) and H (⊥) decreased with draw, suggesting the softness of the smectic phase. The anisotropy, H (⊥)/ H (/ t |), for samples forged at 50°C is higher than that for samples forged at 140°C at a comparable compression ratio ( CR ), e.g. at CR = 7.5, H (⊥)/ H (/ t |) for 50°C and 140°C are 2.7 and 2, respectively. The impact strength of forged iPP was very different from the results of the indentation test. For samples forged at 50 and 140°C, the strength both parallel and perpendicular to the forged sample surface increased strongly with draw. The strength tested along the planar direction is about twice that tested through the thickness direction. Testing in each direction broke the samples into layers. The mechanism of energy absorption is closely related to the morphology-developed planar orientation with the crystal b -axis orientation normal to the plane direction.

The phase structures of uniplanar-drawn isotactic polypropylene (iPP) have been investigated. Three phases (α-crystal, smectic and amorphous) are found to coexist in the uniaxially compressed samples. From thermal analyses and density measurements, the fractions and densities of these phases have been evaluated. At a compression draw temperature of 50°C Ts, decrystallization without smectic phase stability proceeded during the deformation. No draw-induced crystallization was observed. At all deformation temperatures, the density of the amorphous phase increased in the initial stage of deformation reaching a limit on further draw.

Isotactic polypropylene (iPP) ( M w = 2.9 × 10 5 ) has been deformed in uniaxial compression by forging at several constant temperatures from 20 to 140°C. A relation between draw efficiency and the formation of the smectic phase during deformation has been examined over a wide range of compression draw ratios (∼50). At a forging temperature below the smectic-phase stability limit temperature ( T s ), the efficiency of draw, parallel to the uniplanar direction, was high (∼97%) and independent of the compression ratio, pressure and draw temperature ( T d ). The relation between the compression yield energy ( E y ) and T d has also been examined. E y , the area under the compressive stress-strain curve up to the yield point, as a function of T d was found to consist of two linear components of different slope. These two linear relations arose from the glassy and crystalline phases. The intercept temperature ( T i ) at zero yield energy for the glassy phase has been evaluated to understand compression drawability. Above T i , the achievable compression ratio ( CR ) increased steadily with T d . At a given T d , the CR increased with increasing applied pressure, and this tendency was more prominent above T i . The T i moved higher as the compression rate was increased.1

Isotactic polypropylene was uniaxially compressed by a forging (uniplanar) process. The physical properties and morphology of the compressed samples were investigated by means of mechanical tests, trirefringence measurement and microscopy. Four major effects of planar deformation on the physical properties and morphology were observed. (1) The glass transition temperature of the compressed sample (evaluated from dynamic mechanical analysis) increased with draw. (2) The smectic phase induced by the compression draw increased sample transparency. (3) Both tensile modulus and strength parallel to the uniplanar direction increased with draw. The smectic phase generated, however, reduced the tensile modulus with no significant effect on tensile strength. (4) The compressed samples possessed a layered structure which was developed by the flattening of the original spherulites.

The relation between molecular weights and electrical properties was investigated for electrochemically prepared poly(3-hexylthiophene) (PHT). The PHT films with weight-average molecular weight (Mw) in the range 12 500–58 000 were prepared by controlling the polyerization conditions. For Mw 25 000, the increase in σ with Mw was minor. The visible absorption maximum ( π−π∗ absorption band) of the neutral PHT films shifted to the red side as Mw increased. The shift was more prominent in the samples with low Mw (

The mechanical properties of electrochemically polymerized polythiophene films were studied in relation to the structure of the films. Both tensile modulus and strength of as-polymerized and neutralized films decreased with increasing current density during polymerization. At a given current density, the tensile properties of neutral films were superior to those of as-polymerized films. The deformability of neutralized films decreased with increasing current density. These results were closely related to the microscopic heterogeneity and chain orientations of as-polymerized films.