Hard Segment Content Research Articles

Characterization of thermo-responsive shape memory bio-based thermoplastic polyurethane (SMTPU) for 3D/4D printing applications

In recent years, significant advancements have been made in smart and multifunctional materials through the integration of 4D printing and shape memory polymers (SMPs). This article highlights key SMP fabrication technologies for 4D printing, focusing on the functionality of stimuli-responsive polymers. Bio-based thermoplastic polyurethanes are produced through the prepolymer polymerization method, with 100% bio-based polyester polyols, polypropylene succinate, and 1,3-propanediol by corn sugar. The resulting SMTPU, which contains bio-polyol in the soft segment, along with a chain extender and isocyanate (4,4-methylene diphenyl diisocyanate, MDI), demonstrates excellent shape recoverability even after significant deformation. Atomic force microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were employed to analyze hydrogen bonding, microphase separation, and crystallinity, providing insights into the interactions between hard segments (HSs) and soft segments (SSs), an extent of phase separation, and a proportion of hydrogen-bonded urethane groups. The tensile strength of 15–21 MPa, elongation between 534 and 585%, and a hardness of 82–85 Shore A were shown. This study further explores the sustainability and unique properties of SMTPU, making it well-suited for shape memory applications at different temperatures with varying hard segment content. The findings are expected to contribute to future innovations and advancements in the field of 4D printing.Graphical

Effect of hard segment content on the phase separation and properties of hydroxyl-terminated polybutadiene thermoplastic polyurethane

Effect of hard segment content on the phase separation and properties of hydroxyl-terminated polybutadiene thermoplastic polyurethane

Preparation and properties of vanillin-based polyurethane materials for body temperature self-healing

It is difficult to obtain sustainable and fast self-healing polyurethane materials with excellent mechanical properties at low-temperature. In this work, we prepared a series of bio-based polyurethane materials were synthesized with HMDI, Polytetramethylene ether glycol and a vanillin-based chain extender containing dynamic imine bonds. By adjusting the ratio of soft and hard segments, As the content of hard segments increased, the storage modulus and tensile strength of the material increased, the elongation at break decreased, and the heat resistance improved. The results showed that this advanced polyurethane displayed excellent mechanical and self-healing properties due to the presence of a large number of hard segment structures with dynamic imine bonds. Moreover, the tight arrangement of hydrogen bonds can promote the exchange of dynamic imine bonds and endow the material with body-temperature self-healing ability. It can recover to 98% of its original stress in 20 min at 36°C.

Effect of Hard Segment Content and Molecular Weight of Liquid Polysulfide on the Microphase Separation Structure–Property of One‐Component Polysulfide Adhesives

ABSTRACTThe degree of microphase separation plays a vital role in one‐component polysulfide adhesives determining their mechanical properties and thermal stability. However, the degree of microphase separation was mainly determined by the hard segment content and molecular weight of liquid polysulfide. In this work, we successfully prepared a series of one‐component polysulfide adhesives with 30 wt%–50 wt% hard segment content by using 4,4‐diphenylmethane diisocyanate (MDI), different molecular weights (1000, 2500, and 4000 g/mol) of liquid polysulfides (JLY‐121/1225/124) and 1,4‐butanedithiol (BSO), and systematically investigated the relationship between microphase separation and material's properties. The results revealed that higher hard segment content and larger molecular weight of liquid polysulfide contributed to forming a higher degree of microphase separation, respectively. Among them, the optimal mechanical properties and thermal stability were obtained at 40 wt% hard segment content when JLY‐1225 (2500 g/mol) was used. After immersion in the oil and water for 21 days, the tensile strength of C40‐1225 could still reach 16.99 ± 0.80 and 14.87 ± 0.30 MPa, with a tensile strength retention rate of 75.75% (oil) and 66.30% (water), confirming that one‐component polysulfide adhesives had good solvent resistance.

Investigating the Impact of Systematic Hard Segment Modulation on Performance of Hydroxyl Terminated Polybutadiene (HTPB) Thermoset Polyurethane Elastomers

ABSTRACTDespite the versatility and extensive applications of hydroxyl‐terminated polybutadiene (HTPB)‐based thermoset polyurethanes (PUs), research on tailoring their performance through hard‐segment modulation is limited. In this study, the impact of hard segment (HS) content modulation (20%–50%) on the properties of two series of HTPB‐based thermoset PU elastomers at R (NCO/OH) 1.5 and 1.6 was investigated. The effect of increasing the HS content on processability, structural confirmation, physico‐mechanical properties, thermal properties, and crystallinity was evaluated through rheological analysis, Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and x‐ray diffraction (XRD). Both series showed 19% and 23% increases in the hydrogen bonding index (HBI) with HS modulation. The pot life at R = 1.5 decreased from 373 to 284 min and at R = 1.6, from 265 to 210 min. The crosslink density, glass transition temperature, and thermal stability increased for both series with higher HS content. At R = 1.5, the tensile strength increased by 105% and the maximum elongation increased to 40% HS before decreasing. At R = 1.6, the tensile strength increased by 81%, and the maximum elongation increased to 30% HS before decreasing. These findings clarify how hard‐segment modulation affects thermosetting PU structure, processing, and performance.

Preparation, structure, and properties of trimethylpentanediol modified polycaprolactone based dendritic shape memory polyurethane

Shape memory mandrel is more and more used in industrial production field. In order to obtain high strength and high precision polymer based products, shape memory mandrel has been widely concerned. Poly(ε-caprolactone) (PCL) is a semi-crystalline polymer. Because of its good degradability and shape memory effect, PCL is considered as an important raw material for the preparation of shape memory mandrel. In this paper, a shape memory polyurethane with a dendritic topological structure was synthesized by molecular cross-linking of poly(ε-caprolactone) diol and 2,2,4-trimethyl-1,3-pentanediol (TMPD). The shape memory polyurethane (SMPU) was characterized by Fourier-transform infrared spectroscopy, gel permeation chromatography, X-ray diffraction spectroscopy, thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, shore A durometer test, and shape memory analysis. The results showed that all the active groups were involved in the reaction, and the crystallinity of the prepared SMPU decreased with the decrease in PCL content. The shape memory effect of SMPU was influenced by PCL and TMPD contents. When the molar ratio of PCL and TMPD in SMPU is 1:3, SMPU has the best shape memory effect. Its shape fixation ratio and shape recovery ratio are 100%, shape memory recovery time is 153.3 s, and hard segment content is 44.85%. In conclusion, PCL based shape memory polyurethane has potential application in mandrels and needs further research.

Properties of thermoplastic polyurethane synthesized from bio‐based diisocyanate for FDM 3D printing

AbstractBio‐based polymeric materials have recently gained popularity due to their unique properties, including environmental friendliness, biodegradability, and sustainability. In this study, the bio‐based TPUs were successfully synthesized by one‐shot polymerization method, utilizing 100% bio‐based polytrimethylene ether glycol (PO3G) as polyols, 71% bio‐based 1,5‐pentamethylene diisocyanate (PDI) as isocyanates, and 100% bio‐based 1,4‐butanediol BDO as chain extenders. The as‐prepared TPUs, which contained up to 92% bio‐based material were investigated using a variety of analytical methods, including morphological investigations, mechanical testing, thermal analysis, rheological behavior, docking analysis, and cytotoxicity studies. For PPB 3 (1:3:2), PPB 4 (1:4:3), PPB 5 (1:5:4), and PPB 7 (1:7:6), the initial modulus values were 78, 151, 194, and 314 GPa, and the shore‐A hardness values were 92, 93, 93, and 94. Additionally, a notable variation in the degree of phase separation (DPS) of 0.575, 0.647, 0.716, and, 0.738 between hard segment (HS) and soft segment (SS) was noticed among synthesized bio‐based TPUs and an increase in DPS with higher molar ratios corresponded to a higher content of HS. Besides, the bio‐based TPU proved outstanding cell viability results, representing its potential appropriateness for various biomedical applications. Eventually, docking simulations were shown in silico to evaluate the interaction of bio‐based TPU with the DNA gyrase enzyme. Furthermore, the results of bio‐based TPUs demonstrated excellent applications in the production of 3D printing using FDM. We effectively prepared 3D printing to provide a viable answer to environmental concerns.

Quantitative Analysis of TPU Microstructure and Performance Optimization across Various Processing Conditions.

Thermoplastic polyurethane (TPU) is essential in resource exploration, healthcare, automotive, and high-end recreational sports. Despite extensive research on TPU's microstructures and their macroscopic properties, the impact of processing conditions like compression and injection molding remains underexplored. This study investigates the influence of processing conditions on TPU by preparing samples with varying hard segment contents using compression molding at 205 °C and injection molding at melt temperatures of 205, 210, 215, and 220 °C, followed by heat treatment at 120 °C for 12 h. Results indicate that injection-molded TPU at 205 °C exhibits lower hydrogen bonding, crystallinity, long period, interfacial thickness, and lamella thickness than compression-molded TPU, leading to higher Young's modulus but lower elongation at break. As melt temperatures increase, these microstructural parameters decrease, reducing Young's modulus and increasing elongation at break. Post heat treatment, microstructural parameters increase, aligning Young's modulus with that of compression-molded samples, while elongation at break surpasses them. This suggests that heat treatment enhances microphase separation by rearranging hard and soft segments. our research reveals a consistent pattern across TPUs with varying hard segment contents, indicating that adjusting processing parameters can effectively regulate microstructure and performance, offering valuable insights for developing high-performance polyurethanes.

CO2-based polyurethane elastomers with enhanced mechanical and tunable room-temperature damping performances

Elastomers provide excellent damping performance owing to their unique viscoelasticity, which are widely used as vibration and noise reduction materials. However, conventional rubber-based elastomers with a low glass transition temperature (Tg) and narrow damping range are difficult to adapt to room-temperature conditions. Additionally, most of petroleum-based elastomers hinder the sustainable development. In this work, a series of novel polyurethane elastomers was synthesized using carbon-fixed CO2-based polycarbonate propylene diol (PPCD). The impact of hard segment (HS) content on the thermal, mechanical, and damping properties of CO2-based polyurethane (PU) was comprehensively investigated. Increasing the HS content from 16 % to 44 % increased the Tg from −3.8 °C to 21.7 °C, covering the entire damping range at room temperature with an adjustable damping performance. Furthermore, the tensile strength increased from 7.2 MPa to 27.0 MPa. The synthesis of CO2-based PU can propel the utilization of PU in damping applications, enabling sustainable advancement of the PU industry.

Self-Healable, Transparent, Biodegradable, and Shape Memorable Polyurethanes Derived from Carbon Dioxide-Based Diols.

A series of CO2-based thermoplastic polyurethanes (TPUs) were prepared using CO2-based poly(polycarbonate) diol (PPCDL), 4,4'-methylenebis (cyclohexyl isocyanate) (HMDI), and polypropylene glycol (PPG and 1,4-butanediol (BDO) as the raw materials. The mechanical, thermal, optical, and barrier properties shape memory behaviors, while biocompatibility and degradation behaviors of the CO2-based TPUs are also systematically investigated. All the synthesized TPUs are highly transparent amorphous polymers, with one glass transition temperature at ~15-45 °C varying with hard segment content and soft segment composition. When PPG is incorporated into the soft segments, the resultant TPUs exhibit excellent self-healing and shape memory performances with the average shape fixity ratio and shape recovery ratio as high as 98.9% and 88.3%, respectively. Furthermore, the CO2-based TPUs also show superior water vapor permeability resistance, good biocompatibility, and good biodegradation properties, demonstrating their pretty competitive potential in the polyurethane industry applications.

Blends of polydimethylsiloxane-based polyurethane and poly (propylene glycol)-based polyurethane with co-continuous structures: Morphology evolution, synergistic effects and application in strain sensors

Blending is an effective way to improve properties of rubbers and develop new materials, so more than 75 % of the rubber consumption in the world is rubber blend. However, blending of thermoplastic elastomers has not yet been emphasized, and few successful examples have been reported. The main challenge for blend systems is compatibility of two components. Herein, a series of (polydimethylsiloxane-based PU)-g-(poly (propylene glycol)-based PU) ((PDMS-PU)-g-(PPG-PU)) graft copolymers with different graft chain lengths and hard segment contents (HSC) were synthesized and utilized as compatibilizers of PDMS-PU/PPG-PU blends. The influence of the structure of compatibilizers on the morphology of blends was investigated, and the compatibilization mechanism was proposed. With the solubilization, the phase structure of blends transforms from “droplet-in-matrix” morphologies to co-continuous ones, and the average size of PPG-PU dispersed phase decreases from 3.5 ± 0.45 μm to 230 ± 60 nm. This is the first time that thermoplastic PDMS-PU/PPG-PU blends with co-continuous structures have been successfully prepared. The properties of blends exhibit synergistic effects. For example, they show high tensile strength of PPG-PU in mechanical properties and unique properties of PDMS in dynamic mechanical properties, weather resistance, water resistance and biocompatibility. In addition, strain sensors were fabricated by introducing carbon nanotubes (CNTs) into the blends, which demonstrated remarkable sensing capability for diverse human body motions.

Effect of hardness on the foaming behavior, surface quality, and mechanical properties of thermoplastic polyurethane foams by chemical foaming injection molding

AbstractAlthough the influence of hard segment content on the foaming behavior of thermoplastic polyurethane (TPU) has been reported in the literature, most of the studies have been limited to batch foaming, and the relationship between hardness on the foaming quality and the surface quality of TPU is still unclear in injection molding foaming. In this study, three hardnesses of TPU foams were prepared by core‐back injection foaming technique to investigate the relationship between hardness and TPU foaming behavior. Firstly, the relationship between hardness and viscosity of TPU was investigated using rotational rheometer. The results showed that the complex viscosity increased with the increase of hardness, especially the viscosity of high hardness TPU responded more significantly at low frequencies. In addition, a scanning electron microscope was used to analyze the cell morphology of TPU foams with different hardness. It was revealed that the cell morphology of 1098A foam with low hardness was deteriorated and deformed severely, with a cell size and cell density of 172.02 μm and 0.59 × 105 cells/cm3, respectively. With the increase of hardness, the cell morphology of high hardness 1071D foam was regular and rounded, its cell size decreased to 95.98 μm and cell density increased 4.43 × 105 cells/cm3. Surface roughness and mechanical experiments showed that the medium hardness 1065D foam had better surface quality and tensile toughness. The elongation at break of the TPU foams decreased with increasing hardness, while the high hardness 1071D foam had better tensile and flexural strength. This study provides understanding for the selection of a suitable hardness to prepare TPU foams with favorable foaming quality and corresponding mechanical properties.Highlights TPU foams of different hardness were prepared using core‐back chemical foaming injection molding technology. High hardness TPU foam had excellent tensile strength and flexural strength.

A Novel Biomedical Polyurethane Material With Optimized Optical and Mechanical Properties Is Developed

Abstract This research aims to design and develop a novel polyurethane elastomer (PUE) material with potential for biomedical optical applications. The study investigates the influence of hard segment (HS) content on transparency and tensile strength to optimize optical and mechanical properties. A one-step polymerization method is employed to synthesize a series of PUEs based on polyester, poly (3-methyl-1,5-pentandioladipate) (PMPA), diisocyanate (4,4-methylene bis (phenyl isocyanate) (MDI)), and the chain extender 1,4 butanediol (BD). By varying the ratios of PMPA/BD/MDI, PUE samples with different HS concentrations are synthesized. Analytical techniques including infrared spectroscopy, refractometer, UV/visible spectrophotometer, and tensile tests confirm the chemical structure of the synthesized PMPAPUE materials and investigate refractive indices (n), transmission spectra, and Young's modulus (YM), respectively. Films (PUE-1, PUE-2, and PUE-3) prepared using solvent-casting techniques exhibit varying optical and mechanical properties. PUE-1, with low HS content, demonstrates excellent transparency, with n = 1.59 and 89.63% of total transmitted light, and possesses excellent elastic properties with a YM of 10.654 MPa and a high strain value of S = 303.7%, meeting lens material requirements, promising for biomedical optical applications. Conversely, PUE-2 and PUE-3, with high HS content, are translucent and stiffer materials exhibiting higher YM, suitable for polymer processing, and tissue engineering applications. The optimization of the material's properties was achieved by carefully tailoring the composition of HS and soft segments, raw material ratios, and optimizing reaction conditions.

Silicone-polyurea based clear viscoelastic films for flexible displays, impact of diisocyanate, chain extender, soft segment molecular weight, and hard segment contents

Clear viscoelastic film (CVF), an optically clear type of press sensitive adhesive (PSA), is crucial for bonding different functional layers together in a display module. With the rapid growth of consumer electronics, foldable display devices offer new challenges to CVF, such as optical clarity, low modulus, low glass transition temperature (Tg), good stress-relaxation, good recoverability, and decent adhesion strength. However, there are some contradictories in combining above properties (e.g., good stress-relaxation vs. good recoverability). Silicone polymers can impart softness and prompt elastic recovery over a wide range of temperatures, thereby making their advantageous features suitable for CVF candidates in flexible display devices. In our previous work, an optimum sample of CVF based on low-hard-segment silicone polyurea (LH-SPU) exhibited well-balanced viscoelasticity for flexible displays. In this work, the impact of diisocyanate, chain extender, soft segment molecular weight, and hard segment contents on SPU elastomeric CVFs (SPU CVFs) for flexible displays was further detailly and systematically evaluated. The different components of SPU can be readily adjusted to prepare CVFs with different properties, such as selectable range of modulus (104 ∼ 105 Pa), temperature plateau (−40 ∼ 120 °C), recoverability (78.15 ∼ 90.97 % under 500 % axial strain), creep-resistance (above 85.5 % creep-recoverability under shear stress of 20, 30, 40, 50 KPa), initial adhesive work (0.17 ∼ 2.23 mJ), and 180° peel strength (9.25 ∼ 14.6 N/25 mm after placing 24 h). Furthermore, the SPU CVFs had undergone 200,000 successive folding reliability tests without any cracking or delamination to verify their potentiality in flexible display devices.

Carbon dioxide‐based poly(hydroxyurethane‐urea) elastomers: Synthesis, microphase structure, and properties

AbstractCompared with isocyanate‐based polyurethanes (PUs), poly(hydroxyurethane)s (PHUs) are more likely to form phase mixing structure, inducing poor elastic properties. To avoid this, stronger interaction between hard segments is required. Herein, carbon dioxide‐based poly(hydroxyurethane‐urea)s (PHUUs) with different hard segment contents were prepared through polyaddition reaction using 5‐membered dicyclic carbonate (BADC) as hard segment, poly(propylene glycol) bis(2‐aminopropyl ether) (D2000) as soft segment, and amino‐terminal polyurea oligomer (HMDA*) chain extender, and several PHUs were prepared by using hexamethylenediamine (HMDA) chain extender or without using chain extender as controls. The interaction between hard segments were strengthened with the introduce of chain extender. Compared with PHUs, PHUUs with HMDA* chain extender were more inclined to form significant microphase separation. For PHUUs, the hard segment Tg appeared at around 60°C when hard segment content reached 40 wt%, and the interdomain spacings were in the range of around 14–23 nm with 40–50 wt% hard segment content. In addition, PHUUs exhibited better solvents resistance and mechanical properties than PHUs with the same hard segment content. PHUUs with certain hard segment content showed good elastic recovery, with a residual strain less than 2% after 10 cycles, which comparable with conventional isocyanate‐based PUs.

Laboratory investigations on influence of thermoplastic polyurethane and its hard segment content on pavement performance of asphalt mixture

ABSTRACT Thermoplastic polyurethane (TPU) is an excellent asphalt modifier, which is consisted of hard and soft segments in the TPU molecular chain. In this paper, The conventional road performances (high and low temperature performance, water stability, fatigue performance and aging resistance) of TPU modified asphalt mixture (TPU-AM) with different hard segment content were evaluated. The results proved that the hard segment of TPU can effectively improve the high temperature performance of asphalt. Compared with TPU-AM with high hard segment content, using TPU with low hard segment content as modifier, the low temperature flexibility and fatigue resistance of TPU-AM are significantly improved. TPU-AM with hard segment content of 40% has excellent high temperature performance, while the TPU-AM with hard segment content of 10% has the best fatigue ability and low temperature performance. The water stability of TPU-AM is obviously stronger than that of base asphalt mixture, although the content of TPU hard segment has little influence on the water stability of TPU-AM. The aging results show that TPU-AM has the best aging resistance when the hard segment content is 30%. Based on the above analysis, the high performance of TPU-AM can be designed by changing the hard segment content.

Novel bio-based polyurethane elastomers for adjustable room-temperature damping property

The distinctive viscoelastic behavior of elastomeres can be exploited for reducing vibrations and noise. However, the utility of conventional rubber-based elastomers is limited by low glass transition temperature (Tg) and narrow adjustable damping range, which constrain the room-temperature damping property. Moreover, the majority of rubber-based elastomers are sourced from unsustainable petroleum-based resources. Therefore, designing bio-based materials with room-temperature high-damping property to replace conventional rubber-based elastomers is crucial. Herein, a novel bio-based polyurethane (bio-PU) elastomer with an adjustable damping-temperature range and room-temperature high-damping property is successfully synthesized from bio-based poly (trimethylene ether) glycol. The effects of molecular chain structure on the thermal properties, mechanical properties, and adjustable damping-temperature range of the bio-PU elastomers, along with the mechanisms underlying these effects, are elucidated in detail. As the content of hard segment increasing, the Tg of bio-PU elastomers significantly increases from −13.0 to 29.9 °C, effectively encompassing the damping temperature range within the room-temperature working range. This promising strategy for formulating bio-based elastomers with adjustable damping-temperature range can advance the sustainable growth of PU industry and broaden the scope of PU damping applications.

One-step facile pathway synthesis of PAPXD/1214-PEA thermoplastic elastomer: Structure and properties

In this study, a novel and facile one-step synthesis route was conducted to prepare semi-aromatic polyamide elastomer (PAPXD/1214-PEA) with p-phenylenediamine, dodecane diamine, dodecanedioic acid and polyether amine (PEA) as monomers. A systematic investigation has been conducted into the effect of hard segment content on the thermal, mechanical and solvent resistance of polymers when semi-aromatic polyamides are used as hard segments. It was found that the melting point of the copolymers gradually increased from 191.2 °C to 231.5 °C with the hard segment content increased from 39 % to 76 %, while the Vicat softening temperature (VST) enhanced from 103.2 °C to 192.2 °C. Compared with the commercial polyamide elastomer Pebax@ (produced by Arkema Inc) with similar hard segment contents, the VST of PAPXD14/1214-PEA were 17.4–66.2 °C higher. The mechanical performance of these elastomers was also largely improved with tensile strength increasing from 15.1 to 40.6 MPa, Young's modulus from 28.2 to 168.7 MPa, toughness from 91.1 to 170.7 MJ/m3. In addition, the solvent resistance properties of PAPXD14/1214-PEA was compared with the commercial polyamide elastomer Pebax@. After soaking in hydrochloric acid for 24 h, the tensile strength of PAPXD/1214-PEA with the hard segment content increased from 50 % to 63 % decreased down to 9.4 and 14.4 MPa, respectively. While the commercial polyamide elastomer Pebax@ (with similar hard segment content) decreased down to 1.5 and 4.3 MPa, indicating the commercial polyamide elastomer products were deteriorated. This suggests the corrosion resistance of the synthesized PAPXD/1214-PEA is much better than that of commercial product, and these semi-aromatic polyamide elastomers can be potentially applied in some harsh service environment especially for high temperature and corrosion sealing.

Synthesis and properties of novel degradable polyglycolide-based polyurethanes

Graphical abstract Polyglycolide-based polyurethane was synthesized via chain extension reaction. As the hard segment content increases, its thermal stability and mechanical properties are improved; and the weight loss rate in PBS solution is reduced.

Research on the performance of three-dimensional-braided-glass fiber reinforced in-situ polymerized TPU

In this study, thermoplastic polyurethane (TPU) is prepared by using 4,4′-methylenediphenyl diisocyanate (4,4′-MDI), poly (1,4-butylene adipate) (PBA), and butane-1,4-diol (BDO). PBA as soft segment for TPU. 4,4′- MDI and BDO as hard segment for TPU. The effects of isocyanate index, hard segment content, and soft segment molecular weight on TPU micro-phase separation, molecular weight, and thermal performance are investigated. 3D-Braided-Glass Fiber (GF) reinforced TPU composites are prepared by in-situ polymerized TPU as the matrix resin. Investigation is conducted into how the mechanical properties and microstructure of the composites are affected by the matrix resin TPU’s structural parameters. As the isocyanate index increases, the mechanical properties of the composites first enhance and then weaken, and the interface bonding between TPU and GF gradually deteriorates. Increasing the molecular weight of soft segments has the same trend of change. With the increase of hard segment content, the mechanical properties of the composites are enhanced. The results demonstrate that the mechanical properties of the TPU/GF composites are at their best when the isocyanate index is 1.01, the hard segment content is 43%, and the PBA molecular weight is 2000, with the stretching strength being 289.6 MPa, the impact strength being 141.8 KJ/mm2, the bending strength being 183.2 MPa, and the flexural modulus being 10.7 GPa.