Z. Roslaniec

Laser-induced periodic surface structures nanofabricated on poly(trimethylene terephthalate) spin-coated films.

Here we present a precise morphological description of laser-induced periodic surface structures (LIPSS) nanofabricated on spin-coated poly(trimethylene terephthalate) (PTT) films by irradiation with 266 nm, 6 ns laser pulses and by using a broad range of fluences and number of pulses. By accomplishing real and reciprocal space measurements by means of atomic force microscopy and grazing incidence wide- and small-angle X-ray scattering respectively on LIPSS samples, the range of optimum structural order has been established. For a given fluence, an increase in the number of pulses tends to improve LIPSS in PTT. However, as the pulse doses increase above a certain limit, a distortion of the structures is observed and a droplet-like morphology appears. It is proposed that this effect could be related to a plausible decrease of the molecular weight of PTT due to laser-induced chain photo-oxidation by irradiation with a high number of pulses. A concurrent decrease in viscosity enables destabilization of LIPSS by the formation of droplets in a process similar to surface-limited dewetting.

Characteristics of multiblock terpoly(ester-ether-siloxane) elastomers

Abstract The structure and physical properties of multiblock terpoly(ester-ether-siloxane) elastomers (EES) have been examined by differential scanning calorimetry, dynamic mechanical analysis, optical microscopy and other standard physical methods. Terpolymers consisted of poly(butylene terephthalate) (PBT), poly-(oxytetramethylene) (PO4) and poly(dimethylsiloxane) (PDMS) segments. The content and length of segments was changed at a constant PBT:PO4 mass ratio of 45:55. At PDMS content above 10% terpolymers were characterized by three glass transition temperatures. EES was characterized by two temperature ranges of elastic state. The characteristic of terpolymers results from their multimicrophase structure and is very specific for thermoplastic elastomers.

Sulfonated Poly(ether-block-ester) Ionomers with Anions in the Polyester Hard Segments

A series of poly(ether–block–ester) ionomers with different content of sodium sulfonate groups in the hard segments, and the random copolyesters poly(butylene terephtalate)/butylene isophthalate (PBT/BI) and poly(butylene terephalate/butylene 5′-sulfoisophthalate sodium salt (PBT/SBI) have been synthesized and examined. The methods of dynamic mechanical thermal analysis and differential scanning calorimetry were used to determine the effect of ionic units on the physical properties of sulfonated poly(ether–block–ester) (SPEE) ionomers and PBT/BI, PBT/SBI copolymers. It was established that the melting temperature and crystallization temperature of the SPEE ionomers decreases with the increase of content sodium 5-sulfoisophthalate in the hard segments, and that the crystallinity gradually decreases with the increase of ionic units content. The effect of ionic units content in hard segments on glass transition temperature of both soft and hard phase, E′, E″ and tan δ were studied. Copyright

POLY(ETHER-BLOCK-SULFONATED ESTER)COPOLYMERS. I. PHASE STRUCTURE AND PHYSICAL PROPERTIES*

The physical properties and a microphase-separated structure of multiblockcopolymers based on flexible segments of poly(1,4-oxytetramethylene)(PTMO) and rigid crystalline segments of poly(butylene terephthalate) (PBT) modified by ionic units were studied. Ionic copolymers were characterizedby limiting viscosity number, melt flow index, and tensile property measurements. The mechanical behavior of ionic poly(ether-block-sulfonated ester)(PESE) copolymers can be compared to that of conventional hard-soft thermoplasticelastomers. The phase structure was studied using differential scanningcalorimetry (DSC). Clearly, the DSC results show that the ionic unitsin the polyester segments have no significant influence on the microphaseseparation structure of PESE. A small reduction of the degree of crystallinitywith increasing content of ionic groups in the polyester rigid segments wasobserved. This results from the effect of ionic forces caused by incorporationof ionic units in the polyester segments. *Dedicated to Prof. Francisco J. Balta´ Calleja on the occasion of his 65th birthday.

Intermolecular interactions in binary multiblock copolymer blends

Abstract The glass transition temperature of the soft phase has been studied in blends of multiblock polyetherester (PEE) with multiblock polyesterurethane (PUA) and poly(ether carbonate)urethane (PUC) copolymer. The K1 and K2 coefficients from the Schneider equation and the q parameter from the modified Kwei equation have been used to monitor the strength of intermolecular interaction. A suggestion for the partial miscibility of the PEE/PUC blends in the soft phase is proposed.

Relaxation Behavior of Poly(ester carbonate) Block Copolymer Across the Melting Region

The dielectric behavior of a family of block copolymers based on poly(butylene terephthalate) (PBT) and aliphatic polycarbonate (PC), with the composition of PBT varying from 100 wt.-% to 40 wt.-%, has been investigated by broad-band dielectric spectroscopy in the frequency range from 10 -1 to 10 9 Hz. At temperatures above the glass transition, the merging of localγ process and the cooperative β process was studied for PBT and 40/60 and 60/40 PBT-PC copolymers. The experimental data can be satisfactorily analyzed considering a sum of two Havriliak-Negami functions indicating that both β and γ relaxations can be treated as independent processes. Dielectric measurements for the 40/60 copolymer were extended over and above the melting region to characterize the influence of crystal melting on the dynamic behavior. It is shown that the progressive loss of the crystalline lamellar stack microstructure, as characterized by differential scanning calorimetry and small- and wide-angle X-ray scattering, provokes a dramatic change in the dynamic behavior of both the β and γ process.

Dynamic mechanical and microcalorimetric studies on the phase structure in blends of two multiblock copolymers: 1. Poly(ether-ester) and poly((ether-carbonate)-urethane) blends

Abstract The physical properties and phase structure of blends of the multiblock poly(ether-ester) elastomer (PEE) and the multiblock poly((ether-carbonate)-urethane) elastomer (PUC) have been investigated using the methods of differential scanning calorimetry and dynamic mechanical analysis. The blends were prepared in the melt. The system is characterized by one glass transition temperature ( T g ) for the soft phase, which points to the occurrence of partial miscibility. The blends appear to possess two hard phases, a polyester phase and a polyurethane phase, with glass transition temperatures and melting points close to the temperatures of the initial copolymers. Suggestions have been made regarding the possibility of occurrence of an intermediate phase conspicuous by extra glass transition and crystallization temperatures.

POLY(ETHER-BLOCK-SULFONATED ESTER) COPOLYMERS. II. MECHANICAL AND DIELECTRIC RELAXATION*

This work reports mechanical and dielectric relaxation studies of multiblock copolymers based on flexible segments of poly(1,4-oxytetramethylene) (PTMO) and rigid crystalline segments of poly(butylene terephthalate) (PBT) modified by ionic units [poly(ether-block-sulfonated ester), PESE]. The dynamic mechanical thermal analysis (DMTA) results indicate that PESE should behave as unvulcanized rubbers at ambient temperature. The changes in the intensities of dielectric relaxation peaks for the β and γ-processes with respect to concentration of rigid segments and ionic unit content in these segments were found to be associated with corresponding changes in crystalline structure and morphology of the PESE. The mechanical and dielectric results show that the degree of crystallinity decreased with increasing content of ionic groups in the polyester rigid segments. At higher concentrations of rigid segments modified by ionic units, the presence of a relaxation that can be due to the ionic aggregation was observed in the DMTA and dielectric spectra. *Dedicated to Prof. Francisco J. Baltá Calleja on the occasion of his 65th birthday.

Poly(ether-block-sulfonated ester) copolymers. III. Morphology and ionic aggregation in PESE

Sulfonated poly(ether–ester) copolymers (PESE) based on poly(butylene terephthalate-co-butylene 5′-sulfoisophthalate sodium salt) and poly(1,4-oxytetramethylene) were studied. Morphological changes that can occur as a consequence of interactions of the sulfonate groups in PESE were investigated by using differential scattering calorimetry (DSC), wide- and small-angle x-ray scattering, and scanning electron microscope measurements. The x-ray scattering and DSC studies show that the degree of crystallinity decreases with increasing content of ionic groups in the polyester rigid segments. This change is the result of ionic forces caused by incorporation of the ionic units. A morphology of ionic aggregates inside microphase-separated poly(butylene terephthalate) domains is suggested.