Microstructure and Mechanical/Elastic Performance of Biobased Poly (Butylene Furanoate)–Block–Poly (Ethylene Oxide) Copolymers: Effect of the Flexible Segment Length (original) (raw)
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Polymers, 2016
A series of poly(trimethylene terephthalate)-block-poly(ethylene oxide) (PTT-b-PEOT) copolymers with different compositions of rigid PTT and flexible PEOT segments were synthesized via condensation in the melt. The influence of the block length and the block ratio on the micro-separated phase structure and elastic properties of the synthesized multiblock copolymers was studied. The PEOT segments in these copolymers were kept constant at 1130, 2130 or 3130 g/mol, whereas the PTT content varied from 30 up to 50 wt %. The phase separation was assessed using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The crystal structure of the synthesised block copolymers and their microstructure on the manometer scale was evaluated by using WAXS and SAXS analysis. Depending on the PTT/PEOT ratio, but also on the rigid and flexible segment length in PTT-b-PEO copolymers, four different domains were observed i.e.,: a crystalline PTT phase, a crystalline PEO phase (which exists for the whole series based on three types of PEOT segments), an amorphous PTT phase (only at 50 wt % content of PTT rigid segments) and an amorphous PEO phase. Moreover, the elastic deformability and reversibility of PTT-b-PEOT block copolymers were studied during a cyclic tensile test. Determined values of permanent set resultant from maximum attained stain (100% and 200%) for copolymers were used to evaluate their elastic properties.
Molecules
This paper aims to compare the performance of two Hytrel-like segmented copolymers: “classic” PBT-b-PTMG and fully bio-based PBF-b-PTMG, containing poly(butylene furanoate) as the rigid segment. The idea behind this research is to assess whether the sustainable copolymers can successfully replace those “classic” once at the thermoplastic elastomers’ market. Two series of copolymers were synthesized under the same process parameters, had the same compositions, but differed in aromatic ring structure in terephthalate/furanoate unit. Furthermore, the materials were processed by injection moulding as typical Hytrel products. Then, the samples were subjected to extensive characterisation including NMR, GPC, FTIR, DSC, WAXS, DMTA, TGA techniques and mechanical tests with particular interest in the microstructure formed during processing and its effect on the copolymers’ mechanical and elastic behaviour. The detailed analysis proved that PBF-b-PTMG and PBT-b-PTMG copolymers represent two k...
Polymers
A series of poly(hexamethylene 2,5-furanodicarboxylate)-block-poly(tetrahydrofuran) (PHF-b-F-pTHF) copolymers were synthesized using a two-stage procedure, employing transesterification and polycondensation. The content of pTHF flexible segments varied from 25 to 75 wt.%. 1H nuclear magnetic resonance (NMR) and Fourier transformed infrared spectroscopy (FTIR) analyses were applied to confirm the molecular structure of the materials. Differential scanning calorimetry (DSC), dynamic mechanical measurements (DMTA), and X-ray diffraction (XRD) allowed characterizing the supramolecular structure of the synthesized copolymers. SEM analysis was applied to show the differences in the block copolymers’ morphologies concerning their chemical structure. The influence of the number of flexible segments in the copolymers on the phase transition temperatures, thermal properties, as well as the thermo-oxidative and thermal stability was analyzed. TGA analysis, along with tensile tests (static and ...
International Journal of Polymer Science, 2021
Homopolymers and copolymers derived from 2,5-furandicarboxylic acid have been extensively studied for their potential in the development of sustainable plastics. This research definitely spotlighted the synthesis of poly(ethylene-co-butylene 2,5-furandicarboxylate) copolymer via the two-step melting polycondensation with various ethylene glycol/1,4-butanediol molar ratios. The structural characterization of the obtained biobased copolymer was carried out by ATR-FTIR and 1H NMR. The average molecular weight of the obtained copolymer was determined by the intrinsic viscosity measurements. It was found that ethylene glycol was preferentially incorporated into the copolymer structures when the molecular weight of the products was not high enough (>18000). The decomposition of two types of monomer units of the obtained copolymer was proven through the degradation two-step process by TGA measurements.
Polymers for Advanced Technologies, 1999
Well-defined ABA triblock copolymers in which A stands for poly(ethylene oxide) (PEO) and B for poly(tetrahydrofuran) (PTHF) were synthesized by end-capping bifunctionally living PTHF with different polyethylene glycol±monomethylethers. Differential scanning calorimetry analysis of these copolymers showed two melting points: one around 55°C due to the PEO blocks, and one around 30°C due to the PTHF segments, demonstrating that these block copolymers show extensive phase separation. Upon addition of sodium thiocyanate, crystalline complexes with PEO were formed and as a consequence, the melting points of the PEO segments had shifted to approximately 170°C, whereas the melting points of the PTHF segments decreased slightly. The obtained materials behave as thermoplastic elastomers up to 160±175°C. The influence of the relative lengths of the PEO and the PTHF segments on the thermal and mechanical properties of the materials have been investigated.
Polymer, 2014
To synthesize high quality (co)polyesters derived from 2,5-furandicarboxylic acid (FA), an acetic acid refluxing/pH-swing method was proposed to purify FA. 2-Carboxyl furfural and other impurities were removed completely from FA with this method. Using highly purified FA, biobased polyester poly(butylene furnadicarboxylate) (PBF) and aliphatic-aromatic copolyesters poly(butylene adipate-cobutylene 2,5-furandicarboxy-late)s (PBAFs) were synthesized via melt (co)polycondensation. The (co) polyesters were characterized with GPC, FTIR, 1 H NMR, DSC and TGA, and their tensile mechanical properties were also assessed. The copolyesters possess random chain structure, monomer feed ratiocontrolled copolymer composition and excellent thermal stability (T d,5% > 340 C) in full composition range. Both BA-rich and BF-rich PBAFs are crystalline polymers. The crystallizability decreases with composition, up to nearly amorphous at moderate f BF (40e60%). PBAFs with f BF no more than 50% exhibit obvious high-elastic deformation and rebound resilience, and possess tensile properties (E 18 e160 MPa, s b 9e17 MPa, ε b 370e910%) comparable to poly(butylene adipate). PBAFs with higher f BF behave like nonrigid plastics with low tensile moduli (42e110 MPa), moderate strength (30e42 MPa) and high elongation at break (310e470%). In comparison, PBF is a strong and tough thermoplastic having balanced mechanical properties, namely, much higher tensile modulus (1.9 GPa) and strength (56 MPa) and high elongation at break (260%). It seems necessary and effective to use highly purified FA for synthesizing high performance FA-derived (co)polyesters.
Polimery
In this study, the effect of thermal aging on the physical transitions, crystalline structure development and the mechanical performance of furan-ester, multiblock copolymers is reported. The materials were synthesized via polycondensation in a melt using 2,5-furandicarboxylic acid (FDCA), 1,3-propanediol (1,3-PD) and dimerized fatty acid diol (FADD). All reagents were plant-derived. The copolymers were characterized by a multiblock structure with randomly distributed poly(trimethylene 2,5-furandicarboxylate) (PTF) and FADD segments and a phase separation forced by the crystallization of the rigid segment. As a consequence, the copolymers revealed elastomeric behavior and a rubbery plateau over a relatively large temperature range and also good processability. However, due to the specific architecture of FDCA-the most important bio-based monomer-the crystallization of the rigid segment was impeded. Differential scanning calorimetry (DSC), wide-angle (WAXS) and small-angle X-ray scattering (SAXS) analyses confirmed a significant development in the crystalline structure due to the thermal treatment. As a consequence, noticeable changes in the mechanical performance of the copolymer samples were observed, which is interesting for potential applications of these new materials.
Polymer International, 2007
Epoxy-based blends containing poly(ethylene oxide)-co-poly(propylene oxide)-co-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers with different PEO/PPO molar ratios have been investigated in order to analyze the effect of the generated morphologies and interactions between components on the mechanical properties of the blends. Mechanical, morphological and dynamic mechanical analyses indicate that the observed increase of flexural modulus can be related to the decrease of free volume. In modified systems that remain miscible, an increase of flexural modulus, strength and fracture toughness can be observed. Also, macrophaseand microphase-separated systems show an increase of fracture toughness but not of flexural modulus and strength at low contents of block copolymers.
2021
Food packaging films must be reinvented in order to answer the new demanding ecological requirements. Biobased and/or biodegradable polymers appear as an interesting alternative to reduce petroleum dependence and carbon dioxide emissions. Poly(ethylene furanoate) (PEF) appears today as a new promising biopolymer thanks to its good gas barrier and mechanical properties, despite its high price that could limit its industrial applications. Its combination with other polymers is thus of great interest and for the first time, film coextrusion process is used to create PLA-PEF and PET-PEF multi-micro/nano layered films. A new PEF grade developed by AVA Biochem in the H2020 Mypack program, has been used and firstly analysed in terms of melt processability, mechanical, thermal and gas barrier properties. Our major results confirmed the good gas barrier as well as mechanical properties of amorphous PEF. Post-extrusion PEF bulk thermal crystallization led to very brittle material making gas b...