Tetramethylene Succinate Research Articles

Degradation of polycarbonate by a polyester-degrading strain, Amycolatopsis sp. strain HT-6.

Amycolatopsis sp. strain HT-6, a poly(tetramethylene succinate) (PTMS)-degrading actinomycete, was observed to degrade poly(tetramethylene carbonate) (PTMC). In a liquid culture with 150 mg of PTMC film, 59% degradation was achieved, but with a low yield of cell growth. On the other hand, PTMS copolymerized with a small amount of PTMC, forming a copolyester carbonate (PEC) that was completely and rapidly degraded with a high yield of cell growth.

Crystalline Phase Transition in Uniaxially Oriented Films of Poly (tetramethylene succinate) Induced by Tensile Extension.

Unaxially oriented films of poly (tetramethylene succinate) [PTMS] were prepared by drawing at room temperature [r. t.]. The films were deformed by tensile extension at r. t., held under a fixed-strain condition at r. t. or at 107°C, and then strain-released at r. t. These processes were examined by the stress-strain [S-S] measurement and the in situ time-resolved wide-angle X-ray diffraction [WAXD] using an Imaging Plate system. The range of strain (e) utilized in this study was 0_??_e<25%.In the range of e where the α_??_β crystalline phase transition takes place, the slope of the S-S curve for each of the extension and strain-releasing processes was smaller than those before and after this range of e. In the holding processes at a fixed strain (e=22_??_23%), any significant difference in WAXD pattern was not recognized between the holding at r. t. and that at 107°C, though the crystalline reflections became sharp and the stress relaxation was fairly promoted at the higher temperature. In the strain-releasing process at r. t. after holding at 107°C, however, the range of e for the α_??_β transition was shifted to the higher strain side. It was concluded that “stress”, not strain, should be a major factor for inducing the transition, and the “critical stress” at r. t. was estimated at about 100MPa.As a mechanical model for the uniaxially oriented PTMS film, the Series-Parallel model with two kinds of amorphous components was found to be adequate for tensile extension at r. t.: One amorphous component is connected in series to the crystalline component, and the other is connected in parallel to the composite of crystalline and amorphous components which are in series. It is considered that the series component has a long relaxation time, but that the parallel one has a shorter relaxation time and can be readily relaxed even at r. t.

Structural Change during Uniaxial Drawing of Unoriented Poly (tetramethylene succinate) Films.

Unoriented films of poly (tetramethylene succinate) [PTMS] were uniaxially drawn at a given temperature (basically at room temperature and occasionally at elevated temperatures). In their drawing process, stress-strain measurements and time-resolved wide-angle X-ray diffraction [WAXD] experiments were carried out.In the drawing process, at first the chain axes (c-axes) of α-form crystallites were gradually oriented in the drawing direction via necking, and then the solid-state phase transformation from α- to β-form crystals occurred increasingly by further drawing. The stress at which the transformation took place was always greater than the yielding stress that was recorded just before the onset of necking. Even at diffrent drawing temperatures ranging from room temperature to 110°C, the transformation occurred at the approximately same strain (or draw ratio), but the stress at which the tranformation took place decreased with increasing temperature.After a run of uniaxial drawing, the sample strip was held still at the final length for more than 120min, but its WAXD pattern displayed only the β-form reflections during such a holding process. In the case of the strip held at a constant strain of 640% for 120min, the stress thereby decreased by 25%, but no α-form reflections were observed in the WAXD pattern. When the stress was fully released, the reflections of β-form disappeared completely and those of α-form appeared again: Finally the uniaxially oriented film of PTMS consisting of α-form crystals was obtained.

Effect of Crystalline and Amorphous Structures on Biodegradability of Poly(Tetramethylene Succinate)

The effect of orientation in the amorphous and crystalline regions on the biodegradability of PTMS [poly(tetramethylene succinate)] was studied using the amorphous orientation function, birefringence, and crystallinity. The crystalline and amorphous intrinsic lateral sonic moduli, E t,c 0 and E t,am 0 , were 2.61 × 103 and 0.41 × 103 MPa, respectively. Using the data on birefringence, crystalline and amorphous orientation function (f ∈ and f am), crystallinity, and sonic modulus of the oriented PTMS fibers, the intrinsic birefringence of the crystalline (Δ c 0 ) and amorphous (Δ am 0 ) regions were evaluated to be 0.0561 and 0.0634, respectively. The biodegradabilities of oriented PTMS films were reduced as the elongation increased, i.e., the amorphous orientation increased. At low elongation (100 and 150%), however, biodegradabilities remained unchanged when the degradation test was performed in activated sludge, which was attributed to the amorphous orientation occurring even at 100% elongation, though the amorphous orientation direction was perpendicular to the fiber axis.

Phylogenetic affiliation of soil bacteria that degrade aliphatic polyesters available commercially as biodegradable plastics.

Thirty-nine morphologically different soil bacteria capable of degrading poly(beta-hydroxyalkanoate), poly(epsilon-caprolactone), poly(hexamethylene carbonate), or poly(tetramethylene succinate) were isolated. Their phylogenetic positions were determined by 16S ribosomal DNA sequencing, and all of them fell into the classes Firmicutes and Proteobacteria. Determinations of substrate utilization revealed characteristic patterns of substrate specificities.

Rheological behavior of cured acrylate-terminated unsaturated copolyesters

The viscoelastic properties of cured acrylate-terminated copolyesters were studied by means of dynamic mechanical analysis. The influence of terminal double bonds, as well as of the cis-trans configuration and distribution along the main chain, on the transition temperatures and rheological properties of the cured polyesters are presented. The presence of double bonds at both chain ends allows the formation of a regular network by crosslinking copolymerization with styrene. The present investigation was carried out on three series of acrylate-terminated copolyesters: poly[(tetramethylene maleate)-co-(tetramethylene phthalate)) (BMPA), poly[(tetramethylene fumarate)-co-(tetramethylene phthalate)] (BFPA) and poly[(tetramethylene phthalate)-co-(tetramethylene succinate)] (BPSA). The results of the mechanical spectrometric analysis are presented as master curves by applying the time-temperature superposition principle. The WLF parameters of the cured unsaturated polyesters were determined above the glass transition temperatures. The glass transition temperatures shift to higher temperatures with increasing degree of crosslinking. The equilibrium shear storage modulus plateau changes as a consequence of the different configuration of the double bonds and the degree of crosslinking. The degree of crosslinking, n c , determined from the equilibrium shear modulus G' e , was higher than those determined from equilibrium swelling measurements. which is apparently connected with the contribution of physical entanglements.

Molecular modelling of helical and extended-chain polyhydroxybutyrates and polytetramethylene succinate

Molecular modelling (MM) has been employed to investigate the crystalline chain conformations of a series of related aliphatic biodegradable polyesters. The bacterial (isotactic) poly (3-hydroxybutyrate) helical conformation of 2.98 Å advance/repeat unit can be cold-drawn to a nearly extended chain conformation possessing an advance of 4.6 Å/repeat unit versus 4.8 Å for complete extension. Syndiolactic PHB has an extended helical chain conformation of 3.85 Å per repeat on account of steric interference between substituents of contiguous R and S units. Molecular modelling techniques have confirmed this result and suggest that up to 25% of S configured units spread randomly or in a stereoblock fashion are isomorphous with the R repeats of isotactic helix segments. From X-ray fibre diffraction data, a low energy crystalline chain conformation for elastomeric poly(4-hydroxybutyrate), P4HB, with a pitch of 11.9 Å per 2 repeat units has been proposed. A synthetic biodegradable polyester, poly(tetramethylene succinate) or Bionolle®, undergoes a reversible strain-induced crystal modification in which the fibre identity period increases from 10.91 Å to 11.97 Å. Plausible conformers are proposed respecting these observed pitches. Modelled P4HB and Bionolle® chains in the ‘all trans’ planar zigzag form correspond to a pitch of 12.4 Å, which overestimates the observed fibre repeat values. Analysis of the crystalline structure of synthetic and bacterial polyesters gives potential insight into their biodegradability, which is controlled by specific enzyme binding characteristics.

Morphological Study on Hydrolytic Degradation of Poly(tetramethylene succinate) Single Crystals and Spherulites

The morphological changes of Poly(tetramethylene succinate) single crystal lamellae by hydrolysis are investigated, using TEM, WAXD and SAXS. And the morphology of PTMS spherulites was also observed by optical microscopy after treatments as well as single crystal lamellae. The edge region of single crystal lamella can be most easily affected in the initial stage of hydrolysis. As the hydrolysis time increases, the lamellae are separated into small fragments which may be started from the uneven or irregular parts of the surface. The WAXD results showed that crystallinity were increased with increasing of treatment time. The lamellar thickness decreased at the initial stage of hydrolysis and increased again. There were cracks on the surface of spherulites after hydrolysis and the direction of cracks were tangential direction of spherulites. This result was thought to be from the uniformity of molecular arrangement in the crystallographic unit cell.

Crystallization behaviour of poly(tetramethylene succinate)

The bulk crystallization behaviour of poly(tetramethylene succinate) (PTMS) has been studied in terms of cooling rate and supercooling. The crystallinity of PTMS increased with decrease in cooling rate during the cooling process from the melt. The equilibrium melting point and the glass transition temperature of PTMS were found to be about 132°C and − 38°C, respectively. The PTMS spherulites appeared to be negatively birefringent, and their linear growth rates were measured at various temperatures isothermally. The growth rate data obtained could be examined in terms of the kinetic theory of crystallization; thus the nucleation parameters of PTMS were explained quantitatively.

Morphology and degradation behavior of aliphatic/aromatic copolyesters

AbstractRandom and segmented block copolymers of Poly(tetramethylene succinate) (PTMS) and Poly(tetramethylene terephthalate) (PTMT) were synthesized and characterized regarding sequence distribution and crystalline parameters. Biodegradation behaviors of the copolyesters were examined in activated sludge and enzyme solution in terms of CO2 evolution. It was found that the initial degradation was strongly dependent on the crystallinity in the random copolymer. However, the chemical compositions become a dominant factor at the later stage of degradation. In the case of block copolymers, the biodegradation rate was most significantly affected by size and degree of perfectness of PTMS crystallites.

Crystal Transition Mechanisms in Poly(tetramethylene succinate)

Poly(tetramethylene succinate) (PTMS) showed a crystal transition between the α (T7GT G̅) and β (T10) form under the strain and relaxation conditions, where T, G, and G̅ denoted trans, gauche, and minus gauche, respectively. We have investigated the mechanisms of this crystal transition by FT-IR and X-ray diffraction. In the FT-IR, the absorbance peaks at 920 cm−1 and 955 cm−1, corresponding to the α form, started decreasing at strain of ε∼8%, while the absorbance at 977 cm−1, corresponding to the β form, appeared at ε∼8%, then increased with strain. In addition, the isobestic point was observed at 965 cm−1, indicating that the crystal transition occurred only between the α and β form, where no amorphous part contributed. In the X-ray diffraction, the meridional reflection of α (at 2θ=25.1°) started decreasing at ε∼8%. In addition, the reflection of β (at 2θ=22.5°) appeared at ε∼8%, then increased with ε. These FT-IR and X-ray results were thus consistent with each other. The molar fraction of the β form, χβ, was determined as a function of stress, σ, by X-ray. The χβ showed a drastic increase at a critical value of σ=140 MPa. It was hence concluded that the thermodynamic first-order phase transition was the operative mechanism of the transition. Such a crystal transition mechanism had been also reported in poly(butylene terephthalate) (PBT). The free energy difference between the α and β form, ΔG, was determined to be ΔG∼1.6 (kJ mol−1 of monomer unit), being close to the reported value of ΔG∼1.4 (kJ mol−1 of monomer unit) for the crystal transition in PBT. The stress–strain curve was measured. The σ increased with ε when ε<8%, then remained approximately constant up to ε∼16%, followed by the second increase for ε>16%. Such a stress–strain characteristics could be explained in terms of the crystal transition.

Microbial degradation of an aliphatic polyester with a high melting point, poly(tetramethylene succinate)

The biodegradability of poly(tetramethylene succinate) (PTMS), a synthetic aliphatic polyester with a high melting point, was evaluated. The ecological study showed that the distribution of PTMS-degrading microorganisms in soil environments was quite restricted compared with the distribution of microorganisms that degrade poly((epsilon)-caprolactone) (PCL), a polyester with a low melting point. However, in soil samples in which the formation of a clear zone was observed, PTMS-degrading microorganisms constituted 0.2 to 6.0% of the total number of microorganisms, which is very close to the percentage (0.8 to 8.0%) observed for PCL-degrading microorganisms. Five strains were isolated from colonies which formed distinct clear zones on agar plates with emulsified PTMS. In liquid cultures of the isolates with ground PTMS powder, strain HT-6, an actinomycete, showed the highest PTMS degrading activity. It assimilated about 60% of the ground PTMS powder after 8 days of cultivation. When a PTMS emulsion was used, a higher degradation rate was observed and more than 90% of the PTMS was assimilated in 6 days. PTMS degradation products were analyzed by gas chromatography, and it was found that 1,4-butanediol, 4-hydroxy n-butyrate, and succinic acid accumulated during cultivation. Degradation of PTMS film by the strain occurred in two steps: fragmentation and then the formation of hemispherical holes on the surface of the film. Strain HT-6 was also able to assimilate PCL and poly((beta)-hydroxybutyrate) (PHB). The crude enzyme showed a wide range of substrate specificity, being able to degrade low-molecular-weight PTMS, PCL, PHB, and even high-molecular-weight PTMS.

Structure and Morphology of Poly(tetramethylene succinate) Crystals

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and Morphology of Poly(tetramethylene succinate) CrystalsK. J. Ihn, E. S. Yoo, and S. S. ImCite this: Macromolecules 1995, 28, 7, 2460–2464Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://doi.org/10.1021/ma00111a045RIGHTS & PERMISSIONSArticle Views1124Altmetric-Citations220LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (3 MB) Get e-Alerts Get e-Alerts

Strain-induced crystal modification in poly(tetramethylene succinate)

A new crystal modification induced by strain was found in uniaxially oriented fibres of poly(tetramethylene succinate). This new modification (β form) had a planar zigzag conformation of T 10 (all trans) and a fibre identity period of 11.90 Å, while the conventional α form had a T 7GTḠ conformation and fibre identity period of 10.90 Å. The solid-state crystal transition between α and β forms was reversible with respect to the successive application and release of strain.

Mechanical properties of cellulose acetate propionate/aliphatic polyester blends

AbstractUseful blends of cellulose esters with other higher molecular weight polymers are generally unknown. Two aliphatic polyesters, poly(tetramethylene glutarate) (PTG) and poly(tetramethylene succinate) (PTS), have been thermally compounded with cellulose acetate propionate (CAP) in the range of 10–40 wt % polyester. These blends have been injection molded, and the mechanical properties of the molded bars were compared to bars molded from CAP plasticized with a low molecular weight diester, dioctyl adipate (DOA). The CAP/aliphatic polyester blends have significantly higher tensile strengths, flexural moduli, heat deflection temperatures, and greater hardness values than the corresponding CAP/DOA blends. © 1994 John Wiley &amp; Sons, Inc.

The Structures and Ionic Conductivity of Complexes Formed by Poly(Tetramethylene Succinate) and Alkali Metal Salts

Abstract The relationship between the structures and properties of solid polymer electrolytes formed by poly(tetramethylene succinate) and alkali metal salts is investigated in this article. The complexation between ions and polar groups, e.g., ester groups in the polymer chains, is determined by FT-IR and XPS techniques. The complexes are semicrystalline materials with the crystallites similar to pure polyester. Inorganic salts do not enter the crystal lattice of the polymer, whereas they do mainly dissolve in the amorphous domains of the polymer. The addition of salts depresses the melting temperature and crystallinity of the polyester. On the contrary, it increases the glass transition temperature. The conductivity of the polyester complexes varies with the concentration, species, solubility of salts in the polyester, temperature, etc. Ionic migration in the amorphous regions of the polymer contributes to the conduction of the electrolytes to a great extent. The conductive behavior could not simply be described either by the Arrhenius equation based on classical theory or by the WLF equation based on free volume theory.