Effective dispersion of fullerene with methacrylate copolymer in organic solvent and poly(methyl methacrylate)

Dispersion of fullerene, C₆₀, by addition of polymethacrylate dispersant in methyl methacrylate (MMA) and incorporation of C₆₀ into poly(methyl methacrylate) (PMMA) were investigated. Copolymers synthesized by radical copolymerization of MMA and 2-naphthyl methacrylate (NMA), poly(MMA-co-NMA), effectively dispersed C₆₀ in MMA to form clusters of 20?nm. In these cases, addition of minimal 110 naphthyl groups per unit C₆₀ molecule afforded to give clusters with minimum of 20?nm sizes. Furthermore, block copolymers, poly(MMA-b-NMA) with MMA/NMA mole ratio from 12:1 to 20:1, also efficiently dispersed C₆₀ to give formation of clusters of 20?nm size by addition of minimal 40 naphthyl groups per unit C₆₀ molecule, which was corresponding to approximate nine layers of naphthyl group in block copolymer adsorbed on the surface of the cluster. Hybrid films of C₆₀/PMMA, prepared by casting of C₆₀-dispersed solution containing PMMA, exhibited absorbance at 400?nm linearly increased with C₆₀ content.     

Atomic force microscopy investigation of asymmetric diblock copolymer morphologies in thin films

Microphase separation and the resulting morphology of asymmetric diblock copolymers of poly(ε-caprolactone) (PCL) in thin films have been investigated by atomic force microscopy. Copolymers consisted of a short block of PCL (M_n∼2500-4500 g/mole) and a longer second block of poly(methyl methacrylate) (PMMA), poly(styrene) (PS) or poly(cyclohexene oxide) (PCHO). Tendency for microphase separation above the glass transition temperature of the second block (PMMA, PS or PCHO) resulted in a pitted morphology on the surface of the thin films. This tendency was strongest for PMMA and weakest for PCHO. The presence of up to 54% PMMA homopolymer in PCL-PMMA block copolymer did not prevent the formation of such pitted morphology on the surface. The effect of the chemical structure of the second block and the possible orientations of the block copolymer molecules in thin films are discussed.     

In-situ synthesis of stable perovskite quantum dots in core-shell nanofibers via microfluidic electrospinning

Perovskite quantum dots (PQDs) possess remarkable optical properties, such as tunable photoluminescence (PL) emission spectra, narrow full width at half maximum (FWHM) and high PL quantum yield (QY), endowing the PQDs great application prospects. However, the inherent structural instability of PQDs has seriously hindered the application of PQDs in various photoelectric devices. In this work, a microfluidic electrospinning method was used to fabricate color-tunable fluorescent formamidinium lead halogen (FAPbX₃, X = Cl, Br, I) PQDs/polymer core-shell nanofiber films. The core-shell spinning nanofiber not only supplies the interspace for the in-situ formation of PQDs, but also significantly reduces the permeability of moisture and oxygen in the air, which greatly improves the stability of PQDs. After adjusting the composition of precursors, the blue-emissive polystyrene (core) and polymethyl methacrylate (shell) coated FAPbCl₃ QDs (abbreviated as PS/FAPbCl₃/PMMA, hereinafter), green-emissive PS/FAPbBr₃/PMMA and red-emissive PS/FAPbI₃/PMMA nanofiber films were fabricated with the highest PL QY of 82.3%. Moreover, the PS/FAPbBr₃/PMMA nanofiber film exhibits great PL stability under blue light irradiation, long-term storage in the air and water resistance test. Finally, the green- and red-emissive nanofiber films were directly applied as light conversion films to fabricate wide-color-gamut display with the color gamut of 125%, indicating their tremendous potentials in optoelectronic applications.     

Crystallization of titania ultra-fine particles from peroxotitanic acid in aqueous solution in the present of polymer and incorporation into poly(methyl methacylate) via dispersion in organic solvent

We report a novel strategy for incorporation of titanium dioxide (TiO₂) particles, which were crystallized from peroxotitanic acid in the presence of hydrophilic polymer by hydrothermal treatment in aqueous solution, into poly(methyl methacrylate) (PMMA) via dispersion into chloroform. Dispersion of TiO₂ particles into chloroform was achieved by solvent change from water to chloroform in aid of amphiphilic polymer dispersant, poly(N-vinyl pyrrolidone) (PVP), poly(N-vinyl pyrrolidone-co-methyl methacrylate) (PVP-co-PMMA), poly(N-vinyl pyrrolidone-block-methyl methacrylate) (PVP-b-PMMA) through azeotropical removal of water. Incorporation of TiO₂ particles into PMMA was carried out by a casting process of a mixture of TiO₂ particles dispersed with PVP₁₅₄-b-PMMA₁₅₆ in chloroform and PMMA on a glass substrate. Resultant hybrid film containing TiO₂ less than 10 wt.% showed high transparency in visible region attributable to homogeneous dispersion into PMMA matrix. The refractive index of the hybrid films increased with TiO₂ content and agreed with the calculated values.     

Non-bioaccumulative, environmentally preferable stabilizer architectures for the dispersion polymerization of MMA in supercritical CO2

To overcome the environmental concerns associated with long-chain perfluorinated compounds, in this report, non-bioaccumulative, environmentally friendly stabilizer architectures based on short-chain fluorinated polymers have been designed for the dispersion polymerization of methyl methacrylate (MMA) in supercritical CO₂. Random copolymers composed of 2-(diisopropylamino)ethyl methacrylate (DPAEMA) and 2,2,3,3,4,4,4-heptafluorobutyl methacrylate (FBMA) or 2,2,3,3,4,4,5,5-octafluoropentyl methacrylate were prepared with various comonomer ratios and utilized as stabilizers. It was found that the copolymers effectively stabilized PMMA latexes in CO₂, leading to the formation of free-flowing, spherical PMMA particles. With increase in the concentration of the stabilizer poly(FBMA-co-DPAEMA) from 2% to 6% (w/w with respected to MMA), the particles diameter decreased from 3.02 to 1.0 μm.     

PMMA: A key macromolecular component for dielectric low-κ hybrid inorganic-organic polymer films

Inorganic-organic composite and hybrid films find widespread applications for the development of functional materials. Polymer matrices with embedded inorganic fillers, nanoparticles or clusters are particularly appealing for optical, electronic, dielectric and magnetic applications. In particular, the development of hybrid layers with tailored dielectric properties represents a key issue in many technological fields.In this framework, poly(methyl methacrylate) (PMMA), due to its outstanding chemico-physical properties, represents a particularly suitable polymer component for the embedding of both microscopic and nanoscopic functional inorganic fillers. The wide use of such a matrix has to be traced back to the favourable combination of chemical and physical properties and easy processing. In this review, the main features and properties of PMMA, with a particular focus on dielectric ones, are firstly briefly described. Selected examples to illustrate the state-of-the art of its corresponding use as dielectric matrix are given and several examples are provided and surveyed.Finally, three case studies concerning PMMA-based hybrid films, produced for very different application fields, are described and discussed. The first example deals with the entrapment of micrometric zinc sulphide powders in PMMA, which acts as a host matrix for the electroluminescent particles in thick film-based Alternate Current Powder Electroluminescent Lamps (ACPELs). The second example describes the preparation of low-κ inorganic-organic hybrid dielectric films based on a PMMA-polyvinylchloride(PVC) blend and a hydrophobic silica powder functionalised on the surface with trimethylsiloxane groups (m-SiO₂). The composition of the investigated materials is [(PMMA)_x(PVC)_y]/(m-SiO₂)_z with z ranging from 0 to 38.3 wt% and x = y = (100 − z)/2. The third case concerns the use of PMMA as a matrix to embed zirconium oxoclusters through the formation of covalent bonds. The obtained material, characterised by a dielectric constant value remarkably lower (1.93 at 1 kHz and 25 °C) than in pristine PMMA (3.0 at 1 kHz and 25 °C), appears as very appealing for the development of microelectronic devices based on low dielectric constant polymer films such as, for instance, field-effect transistor (FET).These three cases are paradigms of three different approaches to composite and hybrid materials based on the embedding of particles in PMMA polymer matrix.     

Modification of TiO<Subscript>2</Subscript> electrode films in dye-sensitized solar cells with PMMA

Nanocrystalline porous TiO₂ electrodes for dye-sensitized solar cells (DSC) are modified by adding polymethyl methacrylate (PMMA). The result shows that large holes are formed in the TiO₂ films, and the short circuit photocurrent density and photoelectric conversion efficiency of DSCs are obviously enhanced compared with those without adding the PMMA. The relationship between the photoelectric conversion efficiency and the amount of PMMA is presented. In particular, the highest conversion efficiency was obtained with TiO₂ electrode films of adding 7.5 wt% PMMA, increasing the conversion efficiency by 27.5%.     

Incorporation of titanium dioxide particles into polymer matrix using block copolymer micelles for fabrication of high refractive and transparent organic–inorganic hybrid materials

We report a novel strategy for incorporation of titanium dioxide (TiO₂) particles into poly(methyl methacrylate) (PMMA) to exploit high refractive and transparent organic–inorganic hybrid materials. Formation of TiO₂ particles of around 20 nm was conducted within hydrophilic core of block copolymer micelles of poly(methyl methacrylate‐block‐acrylic acid) (PMMA‐b‐PAA) in toluene via sol–gel process from titanium isopropoxide and hydrochloric acid. Subsequently, incorporation of TiO₂ particles into PMMA matrix was carried out by casting toluene solution of TiO₂ precursor‐loaded copolymer micelles, prepared from PMMA₃₅₀‐b‐PAA₉₃ and the precursor of mole ratio Ti⁴⁺/carboxyl 4.0, and PMMA. Hybrid films of TiO₂/PMMA exhibited high transparency to achieve transmission over 87% at 500 nm at 30 wt % of TiO₂ content. The refractive index of resulting hybrid films at 633 nm linearly increased with TiO₂ content to attain 1.579 at 30 wt % TiO₂, which was 0.1 higher than that of PMMA. Cross‐sectional transmission electron microscope images of TiO₂/PMMA hybrid films showed existence of TiO₂ clusters less than 100 nm, which were probably formed by aggregation or agglutination of TiO₂ particles during a drying process. It was also observed that decomposition temperature of the hybrid films elevated with increasing TiO₂ content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Corrosion protection of iron surface modified by poly(methyl methacrylate) using surface-initiated atom transfer radical polymerization (SI-ATRP)

A new N-heterocyclic initiator N-[2-(8-heptadecenyl)-4,5-dihydro-1H-imidazole-1-ethyl]-2-bromoisobutyramide was synthesized and immobilized on the surface of iron. Methyl methacrylate was grafted from iron substrates via surface-initiated atom transfer radical polymerization (ATRP). The first-order kinetics of poly(methyl methacrylate) (PMMA) grafting from iron revealed the control of ATRP throughout the reaction, and the polymerization reached a high conversion producing polymers with good control of molecular weights (M _n?=?68,800) and low polydispersity indexes (M _w/M _n?<?1.32). The thickness of the polymer brush films was greater than 47 nm after 7 h of reaction time. The grafting density was estimated to be 0.48 chains?nm^?2. The iron surfaces at various stages of modification were characterized by scanning electron microscopy and energy dispersive spectrometer. The analytical results were consistent with a thin compact polymer coating on the surface of iron. Iron surface with grafted PMMA coating showed significant corrosion resistance. This work demonstrated that the surface-initiated ATRP is a versatile means of the surface modification of active metals with well-defined and functionalized polymer brushes.     

The effect of zinc bromide on the thermal degradation of poly(methyl methacrylate): Part 1—Thermal analysis studies and general nature of the interaction

The degradation behaviour of several different blends of poly(methyl methacrylate) (PMMA) and zinc bromide, under programmed heating to 500°C, has been studied using thermal volatilisation analysis and spectroscopic investigation of the volatile degradation products. The samples were in the form of films cast from a common solution of the components in acetone; these films are found to be transparent, indicating compatibility of PMMA and ZnBr₂. From studies of the visible spectra of cobalt bromide, PMMA and blends of PMMA with CoBr₂, it has been argued that complex formation occurs between the polymer and the transition metal halides: structures are suggested.When degraded alone, PMMA gives only monomer as the degradation product. In the blends with ZnBr₂ (or with CoBr₂), the polymer becomes considerably less stable and the pattern of degradation becomes very complex, with a range of volatile products, of which methyl bromide, carbon dioxide and methanol are the major constituents; carbon monoxide and methane are also formed. It is proposed that complex formation facilitates the release of methyl bromide as the first stage of breakdown, with the formation of zinc methacrylate units in the polymer chain; depolymerisation is prevented or severely inhibited, depending on the amount of ZnBr₂ present.     

Permeability to oxygen of poly(methyl methacrylate) films containing silane-treated glass flakes

Permeability to oxygen of poly(methyl methacrylate) (PMMA) films containing glass flakes (GF) was investigated. The glass flakes were treated with five kinds of silanes and K₂Cr₂O₇-H₂SO₄ solution to improve the affinity with PMMA. The permeability curves were classified into five representative types, which depend on the pretreatment of the glass flakes and the type of silane used as a coupling agent. The factors which influence permeability were studied from the point of view of permeative retardation with the aid of several methods, such as determination of the apparent density of the glass flakes treated with the silanes, the shearing and tensile strength of the PMMA films containing the glass flakes, ESR spectra of films irradiated by γ-rays, and x-ray diffraction patterns of the films. It was found that the three very effective methods to retard the permeability are (a) pretreatment of the glass flakes with NaOH, (b) treatment with γ-methacryloxypropyltrimethoxysilane or ditrimethylsiloxymethylsilane, and (c) heat pressing of the films. The lowest permeability constant which was attained in this study was about one-eighth that with PMMA alone.     

The disorderly exfoliated LDHs/PMMA nanocomposites synthesized by in situ bulk polymerization: The effects of LDH-U on thermal and mechanical properties

The disorderly exfoliated layered double hydroxides/poly(methyl methacrylate) (LDHs/PMMA) nanocomposites were obtained in a two-stage process by the in situ bulk polymerization of methyl methacrylate (MMA) in the presence of 10-undecenoate intercalated LDH (LDH-U). The dispersed behavior of the LDH-U in the PMMA matrix was identified by using X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV/visible transmission spectroscopy. All these nanocomposites showed significantly enhancement of glass transition temperature (T_g) and the decomposition temperatures compared to pristine PMMA, as identified in differential scanning calorimetry (DSC) and thermogravimetric (TGA) analysis. The tensile modulus of these nanocomposites was also enhanced by incorporating the LDH-U into the PMMA matrix and increased as the amount of LDH-U increased. According to the analytical method of Ozawa-Flynn, the degradation activation energies of these nanocomposites are higher than that of pristine PMMA.     

Structural,surface, optical,and antimicrobial characterization of I2/Polymethyl methacrylate and CuS/I2/polymethyl methacrylate thin films

In this study, I₂/PMMA and CuS/I₂/PMMA thin films were produced by Chemical Bath Deposition (CBD) on polymethyl methacrylate (PMMA) substrates, and their physicochemical and antimicrobial properties were analyzed. The film's surface tensions were characterized by KSV instruments, and the surface tensions for plain PMMA, I₂/PMMA, and CuS/I₂/PMMA thin films were 30.27, 28.77, and 31.86 mN/m, respectively. The I₂ and CuS/I₂ structures in the XRD patterns are amorphous. After coating CuS, the long rod-like extension structures are formed; spherical shapes form some agglomeration in some regions to SEM images. Chemical analysis was performed with an EDX spectrometer attached to SEM. The thicknesses and surface roughnesses of I₂/PMMA and CuS/I₂/PMMA thin films were determined to be 50.34 nm, 1126 nm; 62.03 nm and 204.99 nm via AFM, respectively. The optical spectra of the films were recorded in the range of 300–1100 nm with a UV-VIS spectrophotometer. The antibacterial and antifungal properties of I₂ and CuS coating were evaluated against facultative gram-negative E. Coli and C. Albicans. The coated films exhibited excellent antimicrobial performance.     

The diverse effect of antiplasticizer in the molecular dynamics of an organic dye-doped polymer observed at different motional lengthscales

Complementary thermal analysis techniques were used to study blending-induced perturbations in polymer dynamics pertaining to different motional lengthscales. The antiplasticizing role of common neutral and apolar fluorescent perylimides on the cooperative relaxation dynamics of poly(methyl methacrylate) (PMMA) chain segments is evidenced by a clear rise of both the glass transition (T_g) and liquid-liquid transition (T_LL) temperatures. Simultaneously, the dielectric strength, Δε_β, of the signal ascribed to restricted rotational movements of lateral groups, shows a substantial reduction. Most aspects of the observed behavior bear analogies with recent experimental observations in nanoconfined PMMAs (e.g., PMMA with homogeneously dispersed SiO₂ nanospheres, in-situ polymerized in silica nanopores or in the form of supported ultrathin films), suggesting that a common mechanism is operational. In our mixtures, confinement effects, such as a modification in the macroconformation of the polymer, and changes in the orientation and packing of the polymer random coil, provide a plausible explanation of the observed changes regardless of the motional lengthscale concerned. Consonant with this scenario are reports of advanced optical properties for perylimide + PMMA blends, ascribed to the high rigidity of the matrix together with weak intercomponent interactions.     

Living radical graft polymerization of methyl methacrylate to polyethylene film with typical and reverse atom transfer radical polymerization

Nickel‐mediated atom transfer radical polymerization (ATRP) and iron‐mediated reverse ATRP were applied to the living radical graft polymerization of methyl methacrylate onto solid high‐density polyethylene (HDPE) films modified with 2,2,2‐tribromoethanol and benzophenone, respectively. The number‐average molecular weight (M_n) of the free poly(methyl methacrylate) (PMMA) produced simultaneously during grafting grew with the monomer conversion. The weight‐average molecular weight/number‐average molecular weight ratio (M_w/M_n) was small (<1.4), indicating a controlled polymerization. The grafting ratio showed a linear relation with M_n of the free PMMA for both reaction systems. With the same characteristics assumed for both free and graft PMMA, the grafting was controlled, and the increase in grafting ratio was ascribed to the growing chain length of the graft PMMA. In fact, M_n and M_w/M_n of the grafted PMMA chains cleaved from the polyethylene substrate were only slightly larger than those of the free PMMA chains, and this was confirmed in the system of nickel‐mediated ATRP. An appropriate period of UV preirradiation controlled the amount of initiation groups introduced to the HDPE film modified with benzophenone. The grafting ratio increased linearly with the preirradiation time. The graft polymerizations for both reaction systems proceeded in a controlled fashion. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3350–3359, 2002     

Dispersion polymerization of methyl methacrylate in supercritical CO2 in the presence of non-fluorous random copolymers

A series of non-fluorous random copolymers, composed of 3-[tris(trimethylsilyloxy)silyl] propyl methacrylate and 2-dimethylaminoethyl methacrylate, poly(SiMA-co-DMAEMA) with different comonomer ratios were prepared and utilized as stabilizers for the free radical dispersion polymerization of methyl methacrylate (MMA) in supercritical carbon dioxide (scCO₂). It was demonstrated that the composition and concentration of the stabilizer have a dramatic effect on the morphology of resulting poly methyl methacrylate (PMMA) latex. When the copolymeric stabilizer poly(SiMA-co-DMAEMA) (71:29) was employed, free-flowing spherical PMMA particles were produced in high yield. As the concentration of stabilizer increases, the resulting size of colloidal particles decreases. In addition, the monomer concentration and initial pressure affected the particle diameter of PMMA.     

Luminescent PMMA Films and PMMA@SiO2 Nanoparticles with Embedded Ln3+ Complexes for Highly Sensitive Optical Thermometers in the Physiological Temperature Range**

In recent years, luminescent materials doped with Ln³⁺ ions have attracted much attention for their application as optical thermometers based on both downshifting and upconversion processes. This study presents research done on the development of highly sensitive optical thermometers in the physiological temperature range based on poly(methyl methacrylate) (PMMA) films doped with two series of visible Ln³⁺ complexes (Ln³⁺=Tb³⁺, Eu³⁺, and Sm³⁺) and SiO₂ nanoparticles (NPs) coated with these PMMA films. The best performing PMMA film doped with Tb³⁺ and Eu³⁺ complexes was the PMMA[TbEuL₁tppo]1 film (L₁=4,4,4-trifluoro-1-phenyl-1,3-butadionate; tppo=triphenylphosphine oxide), which showed good temperature sensing of S_r=4.21 % K⁻¹ at 313 K, whereas for the PMMA films doped with Tb³⁺ and Sm³⁺ complexes the best performing was the PMMA[TbSmL₂tppo]3 film (L₂=4,4,4-trifluoro-1-(4-chlorophenyl)-1,3-butadionate), with S_r=3.64 % K⁻¹ at 313 K. Additionally, SiO₂ NPs coated with the best performing films from each of the series of PMMA films (Tb–Eu and Tb–Sm) and their temperature-sensing properties were studied in water, showing excellent performance in the physiological temperature range (PMMA[TbEuL₁tppo]1@SiO₂: S_r=3.84 % °C at 20 °C; PMMA[TbSmL₂tppo]3@SiO₂: S_r=3.27 % °C at 20 °C) and the toxicity of these nanoparticles on human cells was studied, showing that they were nontoxic.     

Synthesis and micelle formation of triblock copolymers of poly(methyl methacrylate)-b-poly(ethylene oxide)-b-poly(methyl methacrylate) in aqueous solution

Amphiphilic triblock copolymers of poly(methyl methacrylate)-b-poly(ethylene oxide)-b-poly(methyl methacrylate) (PMMA-b-PEO-b-PMMA) with well-defined structure were synthesized via atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) initiated by the PEO macroinitiator. The macroinitiator and triblock copolymer with different PMMA and/or PEO block lengths were characterized with ¹H and ¹³C NMR and gel permeation chromatography (GPC). The micelle formed by these triblock copolymers in aqueous solutions was detected by fluorescence excitation and emission spectra of pyrene probe. The critical micelle concentration (CMC) ranged from 0.0019 to 0.016 mg/mL and increased with increasing PMMA block length, while the PEO block length had less effect on the CMC. The partition constant K_v for pyrene in the micelle and in aqueous solution was about 10⁵. The triblock copolymer appeared to form the micelles with hydrophobic PMMA core and hydrophilic PEO loop chain corona. The hydrodynamic radius R_h,app of the micelle measured with dynamic light scattering (DLS) ranged from 17.3 to 24.0 nm and increased with increasing PEO block length to form thicker corona. The spherical shape of the micelle of the triblock copolymers was observed with an atomic force microscope (AFM). Increasing hydrophobic PMMA block length effectively promoted the micelle formation in aqueous solutions, but the micelles were stable even only with short PMMA blocks.     

Eu(III) complex-doped PMMA having fast radiation rate and high emission quantum efficiency

Three ternary luminescent complexes, Eu (deuterated 1,3-diphenyl-1,3-propanedione)₃(1,10-phenanthroline), Eu (deuterated 1,3-diphenyl-1,3-propanedione)₃(2,2′-bipyridine), and Eu (deuterated 1,3-diphenyl-1,3-propanedione)₃ (bathophenanthroline) were synthesized using bidental oxygen and nitrogen as ligands. Luminescent polymers were fabricated by incorporating deuterated Eu(III) complexes in a poly(methyl methacrylate) matrix. Luminescent poly(methyl methacrylate) containing Eu (deuterated 1,3-diphenyl-1,3-propanedione)₃ (bathophenanthroline) exhibited relatively higher quantum yield, faster radiation rate, sharper red emission and larger stimulated emission cross-section (quantum yield 36%, radiation rate 8.6 × 10² s^?1, full width at half maximum 3.4 nm, and stimulated emission cross-section σ _p = 1.4 × 10^?20 cm²) of the PMMA matrix. The value of σ _p was the same order as the values of Nd-glass laser for practical use. Additionally, the thermal behaviors of the Eu(III) ternary complexes were studied, and the results indicated that all of them can be long-term used in high temperature environment. Prepared luminescent polymer including Eu (deuterated 1,3-diphenyl-1,3-propanedione)₃ (bathophenanthroline) showed promising results for applications in novel organic Eu(III) devices, such as high-power laser materials and optical fibers.     

Study on the PMMA/GO nanocomposites with good thermal stability prepared by in situ Pickering emulsion polymerization

Graphene oxide (GO) is used as a stabilizer in the Pickering emulsion polymerization of methyl methacrylate (MMA) to prepare PMMA/GO nanocomposites. Transmission electron microscope studies of the emulsion polymerization products showed that the average diameter of nanocomposite particles was about 150 nm, the transparent GO flakes covered the surface of the particles, and were well dispersed in polymer matrix. The influence of GO on the thermal stability of PMMA was investigated by thermogravimetry analysis and differential scanning calorimetry. The results showed that the thermal stability and the glass transition temperature (T _g) of PMMA/GO nanocomposites were improved obviously compared with PMMA. The apparent activation energy (E _a) for the degradation process of PMMA/GO nanocomposites was evaluated by Kissinger method, which indicated that their E _a s were much higher than those of PMMA both in nitrogen and air atmosphere.