High Glass Transition Temperature Research Articles

Polymeric Fibers with High Strength and High Toughness at Extreme Temperatures.

Developing strong and simultaneously tough polymeric materials with excellent thermal stability and mechanical performance even under extreme temperatures is truly a challenge. In a disruptive progress, continuous polymeric yarns are developed with a combination of high tensile strength of (1145 ± 44) MPa and ultrahigh toughness of (350 ± 24) J g-1 and high thermomechanical properties from -196 to 200°C. The comprehensive thermomechanical performance of this yarn surpasses that of previously developed polymeric materials and dragline spider silks. The results demonstrate that the molecular structure of polyimide (PI) with the incorporation of flexible-rigid macromolecular, hierarchically spiral-oriented fibers, and high glass transition temperature (248°C) are keys for the yarn's notable comprehensive performance in thermomechanical properties. The materials are ideal for technical components exposed to high thermomechanical loadings, such as those encountered in spacecraft or automotive engineering for safety-critical applications.

6-Carboxycellulose Acetate Butyrate: Effectiveness as an Amorphous Solid Dispersion Polymer.

Amorphous solid dispersion (ASD) in a polymer matrix is a powerful method for enhancing the solubility and bioavailability of otherwise crystalline, poorly water-soluble drugs. 6-Carboxycellulose acetate butyrate (CCAB) is a relatively new commercial cellulose derivative that was introduced for use in waterborne coating applications. As CCAB is an amphiphilic, carboxyl-containing, high glass transition temperature (Tg) polymer, characteristics essential to excellent ASD polymer performance, we chose to explore its ASD potential. Structurally diverse drugs quercetin, ibuprofen, ritonavir, loratadine, and clarithromycin were dispersed in CCAB matrices. We evaluated the ability of CCAB to create ASDs with these drugs and its ability to provide solubility enhancement and effective drug release. CCAB/drug dispersions prepared by spray drying were amorphous up to 25 wt % drug, with loratadine remaining amorphous up to 50% drug. CCAB formulations with 10% drug proved effective at providing in vitro solubility enhancement for the crystalline flavonoid drug quercetin as well as ritonavir, but not for the more soluble APIs ibuprofen and clarithromycin and the more hydrophobic loratadine. CCAB did provide slow and controlled release of ibuprofen, offering a simple and promising Long-duration ibuprofen formulation. Formulation with clarithromycin showed the ability of the polymer to protect against degradation of the drug at stomach pH. Furthermore, CCAB ASDs with both loratadine and ibuprofen could be improved by the addition of the water-soluble polymer poly(vinylpyrrolidone) (PVP), with which CCAB shows good miscibility. CCAB provided solubility enhancement in some cases, and the slower drug release exhibited by CCAB, especially in the stomach, could be especially beneficial, for example, in formulations containing known stomach irritants like ibuprofen.

High Glass Transition Temperature Fluorinated Polymers Based on Transfer Learning with Small Experimental Data

High Glass Transition Temperature Fluorinated Polymers Based on Transfer Learning with Small Experimental Data

Thermally Stable and Transparent Polyimide Derived from Side-Group-Regulated Spirobifluorene Unit for Substrate Application.

Advancements in flexible electronic technology, especially the progress in foldable displays and under-display cameras (UDC), have created an urgent demand for high-performance colorless polyimide (CPI). However, current CPIs lack sufficient heat resistance for substrate applications. In this work, four kinds of rigid spirobifluorene diamines are designed, and the corresponding polyimides are prepared by their condensation with 5,5'-(perfluoropropane-2,2-diyl) bis(isobenzofuran-1,3-dione) (6FDA) or 9,9-bis(3,4-dicarboxyphenyl) fluorene dianhydride (BPAF). The rigid and conjugated spirobifluorene units endow the polyimides with higher glass transition temperature(Tg) ranging from 356 to 468 °C. Their optical properties are regulated by small side groups and spirobifluorene structure with a periodically twisted molecular conformation. Consequently, a series of CPIs with an average transmittance ranging from 75% to 88% and a yellowness index (YI) as low as 2.48 are obtained. Among these, 27SPFTFA-BPAF presents excellent comprehensive performance, with a Tg of 422 °C, a 5wt.% loss temperature (Td5) of 562 °C, a YI of 3.53, and a tensile strength (δmax) of 140MPa, respectively. The mechanism underlying the structure-property relationship is investigated by experimental comparison and theoretical calculation, and the proposed method provides a pathway for designing highly rigid conjugated CPIs with excellent thermal stability and transparency for photoelectric engineering.

Conjugation-Broken Dimer Acceptors Enable High-Efficiency, Stable, and Flexibility-Robust Organic Solar Cells.

Dimer acceptors in organic solar cells (OSCs) offer distinct advantages, including a well-defined molecular structure and excellent batch-to-batch reproducibility. Their high glass transition temperature (Tg) aids in achieving an optimal kinetic morphology, thereby enhancing device stability. Currently, most of dimer acceptor materials are linked with conjugated units in order to obtain high power conversion efficiencies (PCEs). In this study, different from previous works on conjugation-linked dimer acceptors, a novel series of dimer acceptors are synthesized (named T1, T4, T6, and T12), each linked with different flexible alkyl linkers, and investigated their PCEs, device stability, and flexibility robustness. When blended with PM6, the T6-based device achieves a PCE of 17.09%, comparable to the fully conjugated T0-based device's PCE of 17.12%. The molecular dynamics simulations anddensity functional theorycalculations suggested that flexible conjugation-broken linkers (FCBLs) promote intermolecular electronic couplings, thereby maintaining good electron mobilities of dimer acceptors. Notably, the T6-based device exhibits impressive long-term stability with a T80 lifetime of 1427h, while in the T0-based device, T80 is only 350h. The present work has thus established the relationship between the length of flexible alkyl linkers in such dimer acceptors and the performance and stability of OSCs, which is important to further designing new materials for the fabrication of efficient and stable OSCs.

Inorganic–organic polymer networks derived from a cyclic siloxane tetrafunctional glycidyl ether resin

AbstractA tetrafunctional glycidyl ether cyclic siloxane epoxy resin (TGTS) has been synthesized, characterized and cured with four aromatic amine hardeners: 1,3‐phenylenediamine (PDA), diethyltoluenediamine (DETDA), 4,4‐diaminodiphenylmethane (DDM) and 1,3‐bis(4‐aminophenoxy)benzene (APB). Each of the cured networks produces transparent and homogeneous networks, although when TGTS is cured with DETDA, reduced compatibility led to lower epoxide consumption, a more heterogenous microstructure and deleterious effects upon properties. Reduced miscibility of DETDA significantly impacts the chemical structure and microstructure of the network, resulting in significant reductions in thermal and mechanical properties but higher UV‐A transmission. The PDA‐, APB‐ and DDM‐cured networks conversely were more miscible and display properties typical of organic–inorganic hybrid networks, such as good mechanical properties at ambient and sub‐ambient temperatures, comparatively high glass transition temperatures, improved resistance to oxidation and lower UV‐A transmission. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Room temperature catalytic upgrading of unpurified lignin depolymerization oil into bisphenols and butene-2

Lignin is the largest source of renewable aromatics on earth. Despite numerous techniques for lignin depolymerization into mixtures of valuable monomers, methods for their upgrading into final products are scarce. The state of the art upgrading methods generally rely on catalytic funneling, requiring high temperatures, catalyst loadings and hydrogen pressure, and lead to the loss of functionality and bio-based carbon content. Here an alternative approach is presented, whereby the target monomers are selectively converted in unpurified mixtures into easily separable final products under mild conditions. We use reductive catalytic fractionation of wood to convert lignin into iso-eugenol and propenyl syringol enriched oil followed by an olefin metathesis to yield bisphenols and butene-2, thus, valorizing all bio-based carbons. To further demonstrate the synthetic utility of the obtained bisphenols we converted them into polyesters with a high glass transition temperature (Tg = 140.3 °C) and thermal stability (Td50% = 330 °C).

Facile construction of recyclable heat‐resistant polymers via alkaline‐induced cation‐π cross‐linking

AbstractThe cation‐π cross‐linked heat‐resistant K‐poly(N‐aryleneindole sulphone) PINSU film, which has a high glass transition temperature (Tg = 268°C) and a decomposition temperature (Td = 547°C), was prepared by soaking PINSU film in alkaline aqueous solutions. Compared with the linear polymer PINSU, the Tg and Td of the K‐PINSU were significantly enhanced. The dynamic cation‐π cross‐linking can be reversibly removed and reconstructed driven by external stimulations in the polymer network, which endows the cross‐linked K‐PINSU with cyclable behavior and excellent mechanical stability. In addition, we have successfully demonstrated that the Tg of the K‐PINSU can be nondestructively detected by monitoring the changes in fluorescence intensity.

Preparation and thermal insulation properties of lightweight high-strength polyimide aerogels containing benzoazole structures

Polyimide (PI) aerogels, serving as thermal insulation materials in extreme environments, stand out for their exceptional high temperature stability and superb thermal insulation properties, rendering them ideal for aerospace, transportation, and specialized equipment industries. However, conventionally synthesized PI aerogels suffer from significant drawbacks in mechanical properties and thermal stability, limiting their practical applications. To overcome this challenge, we successfully synthesized polyimide aerogels using biphenyl-3,3,4,4′-tetracarboxylic dianhydride (BPDA), 5-amino-2-(4-aminophenyl)benzimidazole (PABZ), and 5-amino-2-(4-aminophenyl)benzoxazole (APBO) followed by supercritical carbon dioxide drying. These synthesized PIs exhibit remarkable thermal stability, with high thermal weight loss temperatures (Td5 %=595–611℃) and high glass transition temperatures. Additionally, these novel PI aerogels demonstrate exceptional thermal insulation properties, high specific surface area, and extremely small pore size. Furthermore, boasting a low dielectric constant (ε=1.72), these newly developed PI aerogels offer along with excellent mechanical properties, holding substantial promise for applications in the forthcoming generation of advanced aerospace and specialized equipment materials.

Poly(ester imide)s with Low Linear Coefficients of Thermal Expansion and Low Water Uptake (VIII): Structure-Flame Retardancy Relationship.

A series of ester-linked tetracarboxylic dianhydrides containing multiple para-phenylene units (TA-pPhs) was synthesized to obtain novel modified polyimides, namely poly(ester imide)s (PEsIs). The flame retardancy and film toughness of PEsIs tended to deteriorate with the structural extension of the repeating units (or monomers) via ester groups. To identify the structural factors necessary for achieving the highest flame retardancy rank (UL-94, V-0), we systematically investigated the structure-property relationships of a series of TA-pPh-based PEsIs. Among them, a PEsI derived from para-quaterphenylene-containing TA-pPh (TA-DPQP) and p-phenylenediamine (p-PDA) exhibited the best property combination, featuring an extremely high glass transition temperature (Tg), very low linear coefficient of thermal expansion (CTE), low water uptake (WA), ultralow linear coefficient of humidity (hygroscopic) expansion (CHE), unexpectedly high film toughness, and excellent flame retardancy (V-0 rank). Moreover, we examined the effects of substituents of TA-pPh and discussed the mode of action for the increased film toughness. This study also investigated the structure-property relationship for a series of PEsIs derived from isomeric naphthalene-containing tetracarboxylic dianhydrides. Some of the PEsIs obtained in this study, such as the TA-DPQP/p-PDA system, hold promise as novel high-temperature dielectric substrates for use in flexible printed circuits.

Bio‐based semi‐aromatic waterborne PIEK‐C sizing agent to construct a robust interface for CF/PEEK composites

AbstractDespite the impressing advances on sizing agents for CF/PEEK composites, the aromatic backbone of the polymer precursors utilized in the vast majority of reports compromises the dispersity and ductility of the slurry, subsequently resulting in inferior overall performance of the composites. Meanwhile, most resins employed for sizing agents in existing reports are based on petroleum resources. Herein, a bio‐based waterborne sizing agent utilizing semi‐aromatic poly ether ketones (PIEK‐C) derived from isosorbide and phenolphthalein has been disclosed, featured by its salutary dispersity, exceptional thermal stability, higher glass transition temperatures, and broader applicability. Due to the structural similarity between the sizing and resin matrix, the protocol endowed CF/PEEK composites with ameliorated overall performance, addressing issues related to inadequate adhesion of CF with PEEK resin, as well as environmental pollution commonly associated with existing commercial epoxy and solvent‐based sizing agents. The Tg and T5% of PIEK‐C‐5050 were 205.08 and 427.16°C, respectively. The particle size range of the PIEK‐C sizing agents spanned from 66.32 to 84.63 nm. The flexural strength and interlaminar shear strength of the composites experienced a respective 993.92 MPa (30.73%) and 83.32 MPa (36.97%) increase compared to untreated CF/PEEK composites following sizing treatment with PIEK‐C‐5050, underscoring expedient intermolecular interactions based on comparable solubility and π‐π stacking effects between the PEEK and PIEK‐C components. This study introduced an efficient and eco‐friendly approach to enhance the interfacial properties of CF/PEEK composites.Highlights PIEK‐C resin is employed for the first time to prepare carbon fiber sizing agents. The PIEK‐C sizing agent significantly fortified the surface energy and wettability of carbon fibers. The CF/PEEK composites after treatment with PIEK‐C sizing agent showed excellent heat resistance. The ILSS and bending strength of the composites were significantly increased by 36.97% and 30.73%, respectively.

Crosslinking Vinyl-Addition Polynorbornenes via Difunctional Diazirines to Generate Low Dielectric-Constant and Low Dielectric-Loss Thermosets.

Thermosets having low dielectric constant (Dk < 3) and low dielectric dissipation factor (Df < 0.003), high glass transition temperature (Tg > 150 °C), and good adhesion to copper are desirable for the low loss layers of the copper clad laminates (CCL) in next generation printed circuit boards. Three different difunctional diazirines are evaluated for both thermal and photochemical crosslinking of a high Tg vinyl-addition polynorbornene resin: poly(5-hexyl-1-norbornene) (poly(HNB)). The substrate polymer, crosslinked by the carbenes generated from the activated diazirines, forms thermosets with Dk < 2.3 and Df < 0.001 at 10GHz depending on the identity of the diazirine and the loading. The Dk and Df values for one composition are stable for 1600h at 125 °C in air and for 1400h at 85 °C and 85% relative humidity, suggesting good long-term reliability of this thermoset. Adhesion of poly(HNB) to copper can be enhanced by priming the copper surface with a diazirine prior to high temperature lamination; peel strength values of greater than 7.5 N cm-1 are achieved. Negative-tone photopatterning of poly(HNB) with diazirines upon exposure to 365nm light is demonstrated.

Vat photopolymerization 3D printing of biobased low viscosity photoactive benzoxazine thermosets

Preparing biobased benzoxazine resin through vat photopolymerization 3D printing is of great significance for its sustainable development and application in cutting-edge fields. In this work, biobased guaiacol and eugenol are used as phenol sources, while 2-(2-aminoethoxy) ethanol with flexible ether bonds is used as an amine source to create photoactive benzoxazine monomers, Eu-BzMA and Gu-BzMA. The viscosity of both monomers at room temperature is lower than 150 mPa·s, which can satisfy the requirements of digital light processing (DLP) 3D printing without adding diluents. The thermal and mechanical properties of the 3D printing benzoxazine resins are studied and the relationship between structure and properties is discussed by comparing the two molecules. Eu-BzMA resin has higher thermal decomposition temperature (T5 = 343 °C), higher hardness (0.70 GPa), higher flexural stress (43.5 MPa) and flexural moduli (2.71 GPa); while, Gu-BzMA resin has higher glass transition temperature (176 °C). This is because Eu-BzMA resin shows higher cross-linking density, but contains more flexible structures formed by allyl crosslinking. In this article, a preparation strategy of low viscosity biobased photoactive benzoxazine is proposed and successfully applied to vat photopolymerization 3D printing.

Development of 3D-printed dual-release fixed-dose combination through double-melt extrusion

This study aimed to develop a 3D-printed fixed-dose combination tablet featuring differential release of two drugs using double-melt extrusion (DME). The hot-melt extrusion (HME) process was divided into two steps to manufacture a single filament containing the two drugs. In Step I, a sustained-release matrix of acetaminophen (AAP) was obtained through HME at 190 °C using Eudragit® S100, a pH-dependent polymer with a high glass transition temperature. In Step II, a filament containing both sustained-release AAP from Step I and solubilized ibuprofen (IBF) was fabricated via HME at 110 °C using a mixture of hydroxy propyl cellulose (HPC-LF) and Eudragit® EPO, whose glass transition temperatures make them suitable for use in a 3D printer. A filament manufactured using DME was used to produce a cylindrical 3D-printed fixed-dose combination tablet with a diameter and height of 9 mm. To evaluate the release characteristics of the manufactured filament and 3D-printed tablet, dissolution tests were conducted for 10 h under simulated gastrointestinal tract conditions using the pH jump method with the United States Pharmacopeia apparatus II paddle method at 37 ± 0.5 °C and 50 rpm. Dissolution tests confirmed that both the sustained-release and solubilized forms of AAP and IBF within the filament and 3D-printed tablet exhibited distinct drug-release behaviors. The physicochemical properties of the filament and 3D-printed tablet were confirmed by thermogravimetric analysis, differential scanning calorimetry, powder X-ray diffraction, and Fourier-transform infrared spectroscopy. HME transforms crystalline drugs into amorphous forms, demonstrating their physicochemical stability. Scanning electron microscopy and confocal laser scanning microscopy indicated the presence of sustained AAP granules within the filament, confirming that the drugs were independently separated within the filament and 3D-printed tablets. Finally, sustained-release AAP and solubilized IBF were independently incorporated into the filaments using DME technology. Therefore, a dual-release 3D-printed fixed-dose combination was prepared using the proposed filament.

Development of single-component epoxy resin with superb thermal stability, flame retardancy, smoke suppression, and latency via Cu-based phosphorus/imidazole-containing complex

To address the growing need for fire-safe single-component epoxy resin (EP) systems, this study introduced a phosphorus-containing copper complex (Cu-DA) as a multifunctional latent curing agent. The Cu-DA complex, synthesized by coordinating copper (II) chloride and a phosphorus-based imidazole, significantly improved the latency, thermal stability, and fire resistance of single-component EP. The obtained EP/Cu-DA-2 mixture with 15.3 wt% Cu-DA showed a 43-day shelf life and a rapid gel time of 22 min at 150 °C, highlighting its superb latency and fast curing. After curing, the resultant thermoset had a high glass transition temperature of 160.9 °C and increased crosslinking density, indicating superior thermal stability. The EP/Cu-DA-3 system with 17.4 wt% Cu-DA achieved a high limiting oxygen index (LOI) of 37.8 % and a UL-94 V-0 rating, reflecting its satisfactory flame retardancy. Furthermore, compared to the control EP system, the total smoke production (TSP) and maximum smoke density (MSD) of EP/Cu-DA-3 were reduced by approximately 28.4 % and 25.8 %, respectively, demonstrating significantly enhanced smoke suppression. The research offers a scalable strategy for developing single-component EP systems with rapid curing, high fire resistance, and great smoke suppression, meeting the demands of industrial applications.

New monomers or co-monomers based on the alkoxyfuranone Scaffold: Toward new alternatives to Petroleum-Based structures

Over the past decade, the circular economy has become a key component of sustainability due to environmental issues and more stringent environmental regulations. In this connection, the valuation of bio-based monomers possessing innovative structures remains an important challenge. Furthermore, several goals must be achieved: 1) the homopolymerization of such bio-based monomers by free radical photopolymerization which requires small energy inputs with limited emission of volatile organic compounds (COV) and 2) their copolymerization with Elium® thermoplastic resins to increase biogenic carbon in these novel low-viscosity methacrylic resins developed by Arkema. The challenge will be, in this context, to maximize the biomass carbon content while maintaining or even surpassing the properties exhibited by their petrochemical counterpart. In this work, a series of alkoxyfuranones derived from furfural have been synthesized. The four alkoxyfuranones (AF1, AF2, AF3 and AF4) varying by the functionality of the side chains (but-3-en-1-yl, acrylate, isopropyl and ethyl) attached via acetalization of the 5-hydroxy-2(5H)-furanone were studied as potential monomers or co-monomers for free radical polymerization. The synthesis of AF1 and AF2 has never been reported in the literature. The homopolymerization of two of them (AF1 and AF2) was successfully achieved, but only one led to a high-glass transition temperature (Tg) bio-based polymer. On the other hand, copolymerization with Elium® thermoplastic resins was obtained with different ratios of AF2 as a co-monomer. As a result, the expected gain value, such as faster photopolymerization was successfully obtained. Nevertheless, the copolymerization doesn’t lead to obtaining high-Tg polymers.

Damage and failure mechanisms of carbon fiber reinforced composite thin-walled bushings under hygrothermal-mechanical loadings

Numerous thin-walled bushings, injection-molded from AS4 short carbon fiber reinforced polyetherketone (AS4/PEK) composites, are employed in the chains of stenter heat-setting machines. These bushings rapidly deteriorate under the hygrothermal-mechanical loadings prevalent in their service conditions. This necessitates regular replacements, critically limiting machine efficiency. In this paper, considering hygrothermal-mechanical loadings, the macro–micro dual-scale damage model of composite bushings is established. The wet and thermal effects are introduced into constitutive models and damage criteria based on the macro–micro mechanics of composites and their constituents. The micro-damage and macro-destruction phenomena in the bushing are analyzed, and the related measures are proposed to delay its failure. Comparing the simulation results with the test, the macro–micro damage and failure behavior are discussed for the failed bushing. It reveals that stress concentrations near AS4 fibers initiate interfacial damage and microcracks in the PEK matrix, inciting interface debonding and matrix fragmentation, ultimately provoking composites failure. Increasing the interface thickness can delay the onset of damage. Fiber tension failure, matrix tensile, and compressive failure induce destruction at the component extremities. According to the influence of hygrothermal performance, within the glass transition temperature range of 160 °C to 240 °C, selecting composites with higher glass transition temperatures can enhance the failure strength of bushings by 19 %. Conversely, within a moisture absorption range of 0.5 % to 0.8 %, opting for materials with lower moisture absorption decreases the failure strength of bushings by 37 %. Optimal failure strength is achieved with composites having a 0.5 % moisture absorption rate and a 240 °C glass transition temperature.

Aromatic nitrile resins with improved processability and thermal properties prepared by collaborative design of structure and blending strategy

The contradiction between processability and thermal properties has been limiting the development of high-performance thermoset resins, especially aromatic nitrile resins (AN). A new AN resin blend of 2-(3-(3,4-dicyanophenoxy)phenyl)-1H-imidazole-4,5dicarbonitrile (PNDCI) and 4-(4-aminophenoxy) phthalonitrile (APN) named PAB based on Brønsted acid-base blending strategy and introduction of asymmetric structure was designed and prepared in this paper. A series of characterizations showed that the PAB has not only excellent processability with a diminished melting point (118°C), wider processing window (90°C), and high curing reactivity, but that the cured PAB resins (C-PAB) also possessed high glass transition temperature (477°C), excellent long-term thermo-oxidative stability, thermomechanical properties and dimensional stability. The present design strategy of blending resins provides PAB as a good reference material for achieving a good balance between processability and high-temperature resistance.

Is a Vitrimer with a High Glass Transition Temperature Available? A Case Study on Rigid Polyimides Cross-Linked with Dynamic Ester Bonds.

Vitrimers, possessing associative covalent adaptable networks, are cross-linked polymers exhibiting malleable (glass-like) feature and recyclable and reprocessable (thermoplastics-like) properties. The dynamic behaviors of vitrimer are dependent on both chain/molecular mobility (glass transition temperature, Tg) and dynamic bond-exchanging reaction rate (topology freezing transition temperature, Tv). This work aims on probing the effect of high Tg on the stress relaxation and physical recyclability of vitrimers, employing a polyimide cross-linked with dynamic ester bonds (Tg: 310°C) as the example. Due to its high Tg and chain rigidity, the cross-linked polyimide does not exhibit a high extent of stress relaxation behavior at 320°C (10°C above its Tg), even though the temperature is much higher than the hypothetical Tv. While raising the processing temperature to 345°C, the cross-linked polyimide exhibits a stress relaxation time of about 3300s and physical malleability. Nevertheless, side reactions may occur in the recycling and reprocessing process under the harsh condition (high temperature and high pressure) to alter the thermal properties of the recycled sample. The diffusion control plays a critical role on the topography transition of a vitrimer having a high Tg. The Tg ceiling is noticeable for developments of vitrimers.

High Glass Transition Temperature Fluorinated Polymers Based on Transfer Learning with Small Experimental Data.

Machine learning can be used to predict the properties of polymers and explore vast chemical spaces. However, the limited number of available experimental datasets hinders the enhancement of the predictive performance of a model. This study proposes a machine learning approach that leverages transfer learning and ensemble modeling to efficiently predict the glass transition temperature (Tg) of fluorinated polymers and guide the design of high Tg copolymers. Initially, the quantum machine 9 (QM9) dataset is employed for model pretraining, thus providing robust molecular representations for the subsequent fine-tuning of a specialized copolymer dataset. Ensemble modeling is used to further enhance prediction robustness and reliability, effectively addressing the problems owing to the limited and unevenly distributed nature of the copolymer dataset. Finally, a fine-tuned ensemble model is used to navigate a vast chemical space comprising 61 monomers and identify promising candidates for high Tg fluorinated polymers. The model predicts 247 entries capable of achieving a Tg over 390 K, of which 14 are experimentally validated. This study demonstrates the potential of machine learning in material design and discovery, highlighting the effectiveness of transfer learning and ensemble modeling strategies for overcoming the challenges posed by small datasets in complex copolymer systems.