Glass Melting Research Articles

Thermal pre-processing before extraction of polyhydroxyalkanoates for molecular weight quality control

Past studies have repeatedly demonstrated the technical feasibility to produce polyhydroxyalkanoate (PHA) using bacterial biomass of mixed microbial cultures (MMCs). Commercial quality grades of poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, can be produced with control of average monomer composition. However, demonstration of PHBV production and recovery with quality control of molecular weight (MW) distribution has been lacking in the research literature. Towards this goal, a workflow has been developed for characterizing molecular weight control by thermal treatment pre-processing of dried PHA-rich biomass before solvent extraction. Dimethyl carbonate (DMC) was a suitable solvent in this workflow in the routine evaluation of extractable PHA. From assessments of DMC extraction using differential scanning calorimetry, 125 °C was selected for nominally 100 percent extraction yield independent of polymer 3-hydroxyvalerate (3HV) content (2 to 41 wt.% 3HV) and molecular weight (100 to 1400 kDa). Intrinsic viscosity measurements of PHBV in DMC at 60 °C was used for molecular weight monitoring. Mark-Houwink constants, α (0.738 ± 0.010) and LogK (-2.016 ± 0.025), were estimated for a PHBV co-polymer blend having 36 wt.% 3HV. A model of random scission supported that weight average molecular weight (Mw) was a more robust metric, compared to number average molecular weight (Mn), for assessing the polymer scission rates. During isothermal heat treatment for a given biomass batch, interpreted scission rate was reproducible and commonly, but not always, constant in time. Scission rates between biomass batches were also variable. Measured properties of the polymer in the biomass (thermal stability, biomass PHA content, PHBV grade, initial moisture content) could not be correlated to this observed batch-to-batch variation of scission rate. Molecular weight loss before extraction did not influence the melting temperatures of the co-polymer blends of PHBV evaluated over a wide sub-eutectic range of average 3HV content. Molecular weight changes for these PHBV co-polymer blends were considered to have likely influenced the nature of blend 3HV distribution, and consequently, crystallization behaviour. Molecular weight loss effects on crystallization behaviour at constant PHBV average 3HV wt.% content could then have contributed to the observed variability for glass transition temperatures and melting enthalpies. However, a reproducible correlation between this variability and MW change was not observed.

ПІДВИЩЕННЯ ЕКОЛОГОЕНЕРГЕТИЧНОЇ ЕФЕКТИВНОСТІ СКЛОВАРНИХ ПЕЧЕЙ

The results of the experimental and computational studies complex on improving the thermal and environmental efficiency of gas-consuming glass furnaces of the regenerative type are presented. The proposed recovery heat technologies of the glass melting fu

Generic α relaxation in a strong GeO_{2} glass melt.

The viscoelastic α relaxation in glass-forming GeO_{2} was measured over a range of temperatures near the glass transition using photon correlation spectroscopy. The relaxation in this "strong" glass former exhibits a nonexponential decay identical to that found in a great many simple organic "fragile" liquids. This finding contradicts the longstanding conjecture that nonexponentiality of viscous relaxations near the glass transition are correlated to the liquid's fragility. Instead, the findings offer support for a recent proposal that the nonexponentiality parameter of the α-relaxation in supercooled liquids displays a universal value β(T_{g})=1/2 near the glass transition.

Combined Effects from Dual Incorporation of ATBC as Plasticizer and Mesoporous MCM-41 as Nucleating Agent on the PLA Isothermal Crystallization in Environmentally-Friendly Ternary Composite Systems.

Different materials, based on an L-rich polylactide (PLA) as matrix, acetyl tri-n-butyl citrate (ATBC) as plasticizer, and mesoporous Mobile Crystalline Material.41 (MCM-41) particles as nucleating agent, were attained by melt extrusion. These materials are constituted by (a) binary blends of PLA and ATBC with different contents of the latest; (b) a dual compound of PLA and a given amount of MCM-41 silica (5 wt.%); and (c) ternary composites that include PLA, ATBC at several compositions and mesoporous MCM-41 at 5 wt.%. Influence of the incorporation of the plasticizer and nucleating particles has been comprehensively analyzed on the different phase transitions: glass transition, cold crystallization, melt crystallization and melting processes. Presence of both additives moves down the temperature at which PLA phase transitions take place, while allowing the PLA crystallization from the melt at 10 °C/min in the composites. This tridimensional ordering is not noticeable in the pristine PLA matrix and, accordingly, PLA crystallization rate is considerably increased under dynamic conditions and also after isothermal crystallization from either the melt or the glassy state. An important synergistic effect of dual action of ATBC and MCM-41 has been, therefore, found.

Effects of reducing atmosphere and iron content on UV transmission property of alkali-silicate and alkali-borosilicate glasses

The effects of the reducing atmosphere during glass melting and the iron content in glass on the ultraviolet (UV) transmission property of borosilicate and silicate glasses were studied. The reducing atmosphere is controlled by the amount of citric acid in each glass batch. The effects of reducing atmosphere on the glass UV transmittance were examined in terms of the distribution of trigonal boron (BO3) and tetrahedral boron (BO4) units and iron reduction index (IRI). Our study reveals that the reducing atmospheres not only had a significant effect on the boron-oxygen structure of alkali-borosilicate glass, but also on the UV transmittance. In addition, IRI has a significant effect on the UV transmittance at a wavelength of 254 nm, with a relative change up to 461%. The iron oxidation state was found to affect the UV absorption coefficient of ferric ion (Fe(III) has about four times greater than that of ferrous ion (Fe(II)) at 254 nm.

Glass-based composites comprised of CaWO4:Yb3+, Tm3+ crystals and SrAl2O4:Eu2+, Dy3+ phosphors for green afterglow after NIR charging

In this paper, we demonstrated the fabrication of new phosphate-based composites with green persistent luminescence after being charged with near-infrared light using the direct doping method. The composites are composed of a phosphate glass and phosphors. The 75NaPO3 − 25CaF2 and 90NaPO3 − 10NaF (in mol%) were the 2 glasses of investigation. The intense blue up-conversion emission between 450 and 500 nm upon 980 nm pumping is obtained by adding CaWO4: Tm3+, Yb3+ crystals in the glass melt before quenching whereas the green persistent luminescence is from the SrAl2O4:Eu2+,Dy3+ phosphors also added in the glass melt. The green persistent luminescence above 0.3 mcd/m2 is observed for ∼30 min after charging with 980 nm due to energy transfer between the upconverter crystals and the persistent luminescent phosphors. Here, the challenges related to the fabrication of such composites are discussed. While it is important for the blue UC emission to be intense to charge the SrAl2O4:Eu2+,Dy3+ crystals, we demonstrate that the glass matrix should not crystallize upon the addition of the different crystals. Additionally, the composites should remain translucent with limited light scattering for the blue UC emission to charge the persistent luminescent phosphors.

Tailoring the performance of boehmite nanoparticles reinforced carboxymethyl chitosan/cashew gum blend nanocomposites via green synthesis

The main motivation for this study stemmed from the demand for bio-friendly polymeric materials with enhanced properties in various fields of application. Biopolymer blend nanocomposite films based on carboxymethyl chitosan (CMCS) and cashew gum (CG) with different contents of boehmite nanoparticles were prepared via a purely green method using water as the solvent. The successful inclusion of boehmite nanoparticles in the CMCS/CG blend was verified by Fourier transform infrared (FTIR) analysis. Scanning electron microscopy (SEM) and optical microscopy were used to analyze the surface microstructure of prepared films. SEM and optical images revealed a uniform distribution of nanofillers in the blend because of the strong interactions between nanoparticles and the CMCS/CG blend segments. The thermogravimetric analysis demonstrates that the addition of boehmite nanoparticles increased the thermal stability of the biopolymer blend films. Differential scanning calorimetry (DSC) showed a small shift in the glass transition and melting temperature of pristine blend to higher values with the addition of boehmite. The correlation of AC conductivity with varying frequency and temperature was evaluated. The maximum conductivity was shown by CMCS/CG blend with 7 wt % boehmite, which was further supported by their lowest activation energy value. Nyquist plots were used to illustrate the complex impedance of prepared nanocomposite films. A decrease in the area under the semicircular arc with temperature suggested an increase in conductivity with temperature. The dielectric constant and dielectric loss factor of blend and its nanocomposite films were found to increase with temperature. Boehmite addition increased tensile strength and hardness while lowering elongation at break up to a specific concentration. The synthesized CMCS/CG/boehmite films can be used as environmentally friendly alternatives in the development of flexible organic electronics and charge harvesting devices.

Synthesis of yttrium titanate stannate (Y2Ti2−xSnxO7, x = 0–2) pyrochlore glass–ceramics as potential nuclear waste form

AbstractY2Ti2−xSnxO7 (x = 0–2) pyrochlore sodium aluminoborosilicate glass–ceramics (GCs) are produced by calcining the pelletized Y–Ti–Sn oxide mixture and glass precursor at 1200 or 1300°C for 4 h. The metal oxide mixture is prepared by a soft chemistry route. X‐ray diffraction, Raman spectroscopy, and electron microscopy are employed to investigate the formation of pyrochlore GCs and local crystal structures. Near phase pure Ti‐rich pyrochlores are produced with minor phase SnO2 observed for Sn‐rich materials. The cell parameters of the pyrochlore structures refined by Le Bail fitting are in good agreement with the published data and increase linearly with the gradual increment of Sn substitution. With progressively increasing Sn proportion on pyrochlore B‐site, Raman characteristic bands of the pyrochlore structure become sharper and well defined. The Raman A1g peak position and its full width at half‐maximum are linearly progressed with increasing x (Sn). The presence of the melting glass facilitates the pyrochlore formation, with ceramic grain sizes ranging from submicron to microns. Transmission electron microscopy and selected area electron diffraction observations indicate the sample possesses a relatively high crystallographic perfection at the atomic level. This new series of pyrochlore GCs and the method disclosed herein may pave the way for further materials development as potential nuclear waste forms.

Alternating [1.1.1]Propellane-(Meth)Acrylate Copolymers: A New Class of Dielectrics with High Energy Density for Film Capacitors.

Polymer dielectrics with high energy density are of urgent demand in electric and electronic devices, but the tradeoff between dielectric constant and breakdown strength is still unsolved. Herein, the synthesis and molar mass control of three alternating [1.1.1]propellane-(meth)acrylate copolymers, denoted as P-MA, P-MMA, and P-EA, respectively, are reported. These copolymers exhibit high thermal stability and are semi-crystalline with varied glass transition temperatures and melting temperatures. The rigid bicyclo[1.1.1]pentane units in the polymer backbone promote the orientational polarization of the polar ester groups, thus enhancing the dielectric constants of these polymers, which are 4.50 for P-EA, 4.55 for P-MA, and 5.11 for P-MMA at 10Hz and room temperature, respectively. Moreover, the high breakdown strength is ensured by the non-conjugated nature of bicyclo[1.1.1]pentane unit. As a result, these copolymers show extraordinary energy storage performance; P-MA exhibits a discharge energy density of 9.73Jcm-3 at 750MVm-1 and ambient temperature. This work provides a new type of promising candidates as polymer dielectrics for film capacitors, and offers an efficient strategy to improve the dielectric and energy storage properties by introducing rigid non-conjugated bicyclo[1.1.1]pentane unit into the polymer backbone.

In-situ study of phase changes in glass by impedance spectroscopy and scaling

Transformation in “evolving glass” in ion-conducting silicate glasses, glass ceramics or ceramics containing an intergranular glass is studied by in-situ impedance spectroscopy and scaling laws. Approaches are developed to scale frequency-dependent electrical conductivity and dielectric properties of multiphase ion-conducting materials to derive temperature-independent information on bulk phases and interfaces in presence. A material's scaled electric conductivity provides a unique response over a range of temperature, if the material remains unaltered, but changes, once modifications in the material occur. Therefore, impedance spectroscopy in combination with scaling can be used for tracking modifications in structure, organization, chemistry and microstructure in “evolving (ion-conducting) glass”.In a first part of this work, our approach is validated through application to stable silicate glasses and glass ceramics. Then “evolving glass” is studied in bulk glasses and ceramics with intergranular glass. Examples include ceramming of glass under formation of a glass ceramic, glass-glass phase separation, modification of intergranular glass in ceramics as result of chemical reactions or melt corrosion.Our approach allows to determine onset of phase separation, nucleation or reaction with high precision. It further reveals that nucleation in our exemplary lithium aluminum silicate glass starts with formation of interfaces (phase separation) prior to forming a well-organized crystal lattice. During phase separation in glass, early capacitive contributions in the impedance spectra indicate that the formation of glass-glass interface precedes the compositional changes in the bulk glass.Impedance of refractories is monitored during thermal treatments or corrosion in glass melt at temperatures up to 1600 °C, and glass characteristics of refractories with glass content as low as 3% are extracted. Conductivity and/or level and/or interconnectivity of the refractory's glass are shown to change during thermal treatments due to reactions between glass and crystalline refractory phases, due to phase transformation or, in case of melt corrosion, due to melt infiltration and ion exchange with the melt.In-situ tracking of impedance and application of scaling laws is shown to be able to reveal changes in bulk glass and intergranular glass.

Physical Properties and Low-Frequency Polarizability Anisotropy and Dipole Responses of Phosphonium Bis(fluorosulfonyl)amide Ionic Liquids with Pentyl, Ethoxyethyl, or 2-(Ethylthio)ethyl Group

This study compared the physical properties, e.g., glass transition temperature, melting point, viscosity, density, surface tension, and electrical conductivity, and the low-frequency spectra under 200 cm-1 of three synthesized ionic liquids (ILs), triethylpentylphosphonium bis(fluorosulfonyl)amide ([P2225][NF2]), ethoxyethyltriethylphosphonium bis(fluorosulfonyl)amide ([P222(2O2)][NF2]), and triethyl[2-(ethylthio)ethyl]phosphonium bis(fluorosulfonyl)amide ([P222(2S2)][NF2]), at various temperatures using femtosecond Raman-induced Kerr effect spectroscopy (fs-RIKES) and terahertz time-domain spectroscopy (THz-TDS). The [P222(2S2)][NF2] had the highest viscosity and glass transition temperature, whereas the [P222(2O2)][NF2] had the lowest. Among the three ILs, the [P222(2S2)][NF2] had the highest density and surface tension, and the [P222(2O2)][NF2] had the highest electrical conductivity. The RIKES and THz-TDS spectral line shapes for the three ILs varied significantly. For the [P2225][NF2], molecular dynamics simulations successfully reproduced the line shapes of the experimental spectra and indicated that the RIKES spectrum was mainly due to the cation and cross-term and their rotational motions, whereas the THz-TDS spectrum was mainly due to the anion and its translational motion. This shows that it is desirable to utilize both fs-RIKES and THz-TDS methods to reveal molecular motions at the low-frequency domain. The [P222(2S2)][NF2] had higher frequency peaks and broader bands in the low-frequency spectra via fs-RIKES and THz-TDS than those for the [P2225][NF2] and [P222(2O2)][NF2].

The crystal growth of NASICON phase from the lithium germanium phosphate glass

The crystal growth rate of LiGe2(PO4)3 phase from lithium germanium-phosphate glass was studied. The glass have been homogenized using the previously established temperature-time conditions, which make it possible to remove volatile substances from the glass melt. The atomic absorption spectrophotometry (AAS) was used to determine the chemical content of the obtained glass and scanning electron microscope (SEM) were used to reveal the isothermal process of crystal growth. The crystal growth rates were determined experimentally and theoretically.

A melt inclusion approach to reconstructing sulfur contents and sulfide saturation of primitive basaltic melts

The study of melt inclusions in minerals is the only direct approach to estimate the contents of volatile components in silicate melts, which are essential to constrain the processes of magma generation and evolution. In particular, the content of sulfur in silicate melts is closely connected with the P-T-fO2 conditions of mantle melting and the formation of sulfide deposits. Inclusions in high-Mg olivine can provide access to the composition of the most primitive melts, but these are the most susceptible to post-entrapment modification such as ‘Fe-loss’. The loss of Fe consequently decreases sulfur solubility and leads to silicate-sulfide immiscibility and formation of daughter sulfide globules, significantly affecting the initial proportions of S contained within the silicate part (glass) of melt inclusions. In this study, we investigated the budget of sulfur in heated and quenched melt inclusions hosted in primitive olivine (87–90 mol% Fo) by accounting for sulfur stored in silicate glass (melt), daughter sulfide globules and shrinkage bubbles. Melt inclusions from MORB-like olivine-phyric rocks (Kamchatsky Mys, Far East Russia) heated for 30 min at 1200 °C and 1300 °C were compared with similar experiments on olivine-hosted melt inclusions over a 5 min duration (at 1200 °C and 1350 °C). Sulfur contents were calculated in the following types of melt inclusions, containing: (i) both sulfide globules and shrinkage bubbles, (ii) only sulfide globules, (iii) only shrinkage bubbles, and (iv) completely homogenized. Our findings indicate that S content in shrinkage bubbles and its precipitates is negligible in reheated water-poor melt inclusions, whereas daughter sulfide globules are significant repositories of initial S. Therefore, when estimating initial S contents in parental melts, the amounts stored in both daughter sulfide and silicate glass should be considered. Our experiments with MORB-type melt inclusions in forsteritic olivine phenocrysts demonstrate that effective homogenization is best achieved by briefly overheating melt inclusions prior to rapid quenching. Although this technique does not allow for the MgFe equilibrium between melt inclusions and their host olivine to be fully achieved, it promotes the dissolution of daughter sulfide globules and shrinkage bubbles, and thus the release of initial sulfur back to the melt/glass.

Biodegradable polyester blends containing multifunctional substances of plant origin

The research aimed to develop polyester materials based on biodegradable polymers (blends of polylactide PLA and poly(hydroxybutyrate) PHB) with additives of plant origin. Substances such as chlorophyll, -carotene, tannic acid and comparative Magenta KeyplastTM dye have been added as stabilisers and dyes of polymer blends.The samples were subjected to thermooxidation and UV aging. Based on changes in mechanical properties, the ageing coefficients K of the composition were calculated. In addition, the colour change was analysed. Thermal transformations of the samples were also determined by differential scanning calorimetry in order to determine the glass transition temperature, melting and crystallisation of materials, as well as to compare the resistance to thermal oxidation of polymeric composition.Chlorophyll, -carotene and tannic acid increased resistance to thermal oxidation of PLA/PHB blends (higher oxidation temperatures in the DSC analysis, indicating a higher resistance to thermal oxidation). Materials with chlorophyll, -carotene and Magenta organic dye had higher ageing coefficientsand, thus, better resistance to degradation. The sample containing -carotene showed a significant colour change under the influence of heat and UV ageing.Concerned the short ageing time of the samples, which may have been insufficient to analyse the degradation process of polymer compositions and the effects of plant stabilising substances. In the future, the ageing time of materials can be extended, and other types of degrading factors can be used.Practical implications include the possibility of using PLA/PHB blends as packaging materials. Adding substances of plant origin allowed obtaining colorful, visually attractive materials, similar to the Magenta dye dedicated to using in polymers. Moreover, the additives allowed control of the degradability of the samples.The originality of the research was the preparation of PLA/PHB polyester blends with the addition of plant substances as multifunctional agents (stabilisers and dyes).

Development and characterization of eco-friendly starch-based plastic reinforcing tea for packaging applications

Petrochemical-based plastics are posing a threat to human existence because of their toxic nature and slow biodegradation rate. However, biodegradable plastics manufactured from natural ingredients are showing hope. The current work deals with developing and characterising starch-based bio-plastic where white vinegar and glycerol have been used as matrix materials and tea has been used as filler material. The developed bio-plastic samples were characterized by soil biodegradation test, Mechanical test, Fourier Transformed Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) analyses. More than 60% of degradation occurred within 28 days. The results proved that the bio-plastic synthesized using used tea has higher tensile strength than those synthesized using black tea. Higher melting point and glass transition temperature were also obtained from the sample synthesized using used tea, confirmed by TGA and DSC analysis. The FTIR analysis confirmed the presence of various organic functional groups. The obtained results were compared with the results available in the literature. Based on the results, the developed bio-plastic samples can be successfully used in packaging applications.

COMPARATIVE ANALYSIS OF EXERGETIC LOSSES IN HEAT RECOVERIES OF GLASS FURNACES

The paper presents the results of a comparative analysis of the exergy losses of heat recovery units of various types included in the waste gas heat recovery systems of glass melting furnaces. Based on the principles of universality and additivity of exergy characteristics, as well as design features of heat recoveries, a comprehensive methodology for studying exergy losses in heat recoveries has been developed. With the help of the developed technique, exergy losses in hot water and hot air heat recoveries, as well as in individual heat exchanger modules, were calculated. A comparative analysis of exergy losses and technological features of heat recovery units included in various schemes for the utilization of waste gases from glass melting furnaces has been carried out. For water-heating heat recoveries, the value of energy losses is less than the value of losses for air-heating heat recoveries. When using water-heating heat recovery units in heat recovery schemes, the coefficient of heat using of the furnace fuel increases, on average, by 20%. Despite the higher level of exergy losses in hot air heat recoveries, taking into account a number of important technological factors determined their competitiveness in heat recovery technologies of glass melting furnaces. At the same time, the heat utilization factor of the furnace fuel increases, on average, by 12.5%.

Green Campaign of The Gili Eco Trust in Forming Public Awareness about The Environment to Realize Gili Trawangan Zero Waste

Gili Trawangan, a renowned tourist destination in West Nusa Tenggara Province, faces a significant waste challenge due to the high influx of visitors. Each day, approximately 20 metric tons of waste, including an astonishing 10,000 glass bottles, accumulate on the island. To instigate a shift in the behavior of the local community, business owners, and tourists, Gili Eco Trust has launched an educational campaign. Additionally, Gili Eco Trust actively engages in community-based waste management by establishing a waste bank and pursuing profitable waste reduction strategies. This includes innovative upcycling of glassware and systematic collection of recyclables, diverting them away from landfills. Gili Eco Trust has Instagram and Facebook accounts. Its social media is interactive. They reply to comments and direct messages from their followers. Online media should be interactive to allow the audience to ask questions about the program. The uploaded caption describes the glass bottle recycling process, starting from cleaning trash, melting glass bottles into glass sand, and becoming strong bricks. This campaign invites and urges local communities and stakeholders to carry out waste management and educate them to protect the environment, provide continuous information, and understand and motivate certain activities or programs through continuous and planned communication.

Rare-earth metals as effective getters for purification of germanium telluride glasses from oxygen impurities

The ability of rare-earth elements (REEs) to bind oxygen impurities in Ge20Te80 and Ga10Ge15Te75 telluride glasses is studied. Thermodynamic calculations and experiments show that REEs in glasses, with the exception of Eu, can significantly reduce the content of oxygen impurities chemically bound with germanium, tellurium, and gallium. The most promising oxygen getters are established to be Y, Gd, Lu, Tm, Dy, Tb, and Ho. The advantages of REEs as the getter compared to traditionally used aluminum are: more complete removal of the getter residue during the distillation of tellurium melt and chalcogenide glass; the absence of intense absorption oxide bands in the range of glass transparency; lower etching ability in relation to the silica-glass reactor.

Ultrafast laser deposition of powder materials on glass

The deposition of various powder materials on borosilicate glass was demonstrated using high-repetition-rate (frep = 1.5 MHz) femtosecond laser light. Melting of the glass substrate was caused by the heat-accumulation effect following multi-photon absorption, while powder materials were melted primarily through linear absorption. This novel processing approach allows the simultaneous melting of glass and powders leading to the formation of either a mechanical joint or fusion welds. The deposition of continuous material tracks was demonstrated for nickel, tin, stainless steel, copper, silicon, as well as silicon oxide powders. Effects of the varying average laser power and focus position on the deposited track morphology were studied. Laser-deposited tin and copper layers with thicknesses up to 60–70 µm were produced.

Synthesis, Thermal Behavior, and Mechanical Properties of Fully Biobased Poly(Hexamethylene 2,5-Furandicarboxylate-Co-Sebacate) Copolyesters.

In this research, three fully biobased poly(hexamethylene 2,5-furandicarboxylate-co-sebacate) (PHFSe) copolyesters with low contents of hexamethylene sebacate (HSe) unit (10 mol%, 20 mol%, and 30 mol%) were successfully synthesized through a two-step transesterification/esterification and polycondensation method. The chemical structure and actual composition of PHFSe copolyesters were confirmed by hydrogen nuclear magnetic resonance. The thermal behavior and mechanical property of PHFSe copolyesters were investigated and compared with those of the poly(hexamethylene 2,5-furandicarboxylate) (PHF) homopolymer. Both PHFSe copolyesters and PHF showed the high thermal stability. The basic thermal parameters, including glass transition temperature, melting temperature, and equilibrium melting temperature, gradually decreased with increasing the HSe unit content. PHFSe copolyesters crystallized more slowly than PHF under both the nonisothermal and isothermal melt crystallization conditions; however, they crystallized through the same crystallization mechanism and crystal structure. In addition, the mechanical property, especially the elongation at break of PHFSe copolyesters, was obviously improved when the HSe unit content was greater than 10 mol%. In brief, the thermal and mechanical properties of PHF may be easily tuned by changing the HSe unit content to meet various practical end-use requirements.