Styrene-methyl Methacrylate Copolymers Research Articles

Determination of complex refractive index of plastics from ultraviolet to mid-infrared by ellipsometry

Plastic litter is a pervasive issue in the ocean, posing threats to both marine ecosystems and human health. In the field of marine remote sensing detection, one common method for detecting and identifying marine plastics is by analyzing their optical characteristics, specifically their spectral remote sensing reflectance. This reflectance is dependent on the complex refractive index of plastics. Therefore, understanding the complex refractive index, which is an intrinsic optical property of plastics, holds significant importance in marine plastics research. In this study, we utilized spectroscopic ellipsometry to measure the complex refractive index of 9 common ploymers including polymethyl methacrylate (PMMA), methyl methacrylate–styrene copolymer (MS), polyethylene (PE), poly (ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), polybutylene terephthalate (PBT), polyoxymethylene (POM), perfluoroalkoxy (PFA), acrylonitrile butadiene styrene (ABS), and styrene-acrylonitrile copolymer (SAN). In addition, we have expanded the complex range of refractive index measurements to include UV and MIR bands with wavelengths up to 32 μm. To ensure the reliability and accuracy of the measurements, experimental results for polycarbonate (PC) were compared with data from the existing literature. The variation of refractive index with wavelength is studied and the causes of absorption peaks in the infrared range are discussed. Furthermore, Considering the dispersion relationship and monomer composition of PMMA, MS, ABS and SAN plastics, a comparative analysis of plastics with commonly used monomers is conducted, and the influence of monomers on refractive index is discussed. Our study indicates that the presence of styrene monomers leads to an increase in the refractive index of plastics in the visible to near-infrared band, while the presence of butadiene monomers results in a decrease.The findings from this study provide fundamental data for future research on marine plastic remote sensing detection applications.

Synthesis of Bimetallic Silver and Copper Alloy Nanoparticles Embedded with Styrene-Methyl Methacrylate Copolymer Nanosphere (SMMA@Ag-Cu) as a Potential Surface Enhanced Raman Scattering (SERS) Substrate

Synthesis of Bimetallic Silver and Copper Alloy Nanoparticles Embedded with Styrene-Methyl Methacrylate Copolymer Nanosphere (SMMA@Ag-Cu) as a Potential Surface Enhanced Raman Scattering (SERS) Substrate

Methyl methacrylate-styrene copolymers prepared by utilizing the Trommsdorff effect in an inverted two-stage extruder

In this work, the influence of initial viscosity on the Trommsdorff effect was firstly investigated, and it was confirmed that 1000 ± 100 Pa · s of viscosity could be a criterion of the Trommsdorff effect. On this basis, a new inverted two-stage extruder was established, the designed ‘blocking unit’ was introduced to the screw configuration, and then the continuous bulk copolymerization of methyl methacrylate (MMA) and styrene (St) was carried out. The results showed that the blocking unit could effectively enhance the residence time of copolymerization, and make the molecular weight distribution of copolymer more uniform. The position of the Trommsdorff effect in the extruder was then determined by the thermal effect of copolymerization, and the mixed monomers were continuously added to effectively utilize the Trommsdorff effect. As a result, the MMA-St copolymers with high molecular weight and narrow distribution were prepared via reactive extrusion, which possessed higher melt flow rate and better thermal stability than pure-PMMA. The present work provides important reference and guidance for the industrialization of bulk free radical copolymerization via reactive extrusion.

Effect of silica nanoparticles on the impregnation process, foaming dynamics and cell microstructure of styrene-methyl methacrylate copolymer/n-pentane foams

In the present study, two-step foaming procedure with a designed in-situ foaming observation apparatus was used to study the foaming dynamics of styrene-methyl methacrylate (St-MMA) copolymer/nanosilica composites. For this purpose, the St-MMA copolymer was synthesized using suspension copolymerization and its nanocomposites were prepared using solution method. The foaming dynamics was studied through temperature-induced (two-step batch foaming) method. Furthermore, the effects of content, size and surface chemistry of silica nanoparticles on the impregnation process, the foaming dynamics and the final morphology of prepared foams were investigated. The impregnation data showed that the presence of silica nanoparticles in matrix prolonged the impregnation and decreased diffusion coefficient. This effect would be clearer where nanoparticle contents are high and the temperature is quite above Tg. The foaming dynamics results illustrated that the nucleation and foaming rate were enhanced with the nanoparticle addition and its size reduction. At the St-MMA copolymer foaming system, the silica nanoparticles with hydrophilic surface chemistry are more efficient in comparison to hydrophobic nanoparticles where all foaming dynamics and the final microstructure parameters were improved.

Polymer-inorganic hybrid coating with biomimetic superhydrophobic property: preparation, characterization, and enhanced stability

To improve the adhesion of superhydrophobic coating to glass substrate, a novel superhydrophobic coating with biomimetic micro-nano structure was prepared by a simple and efficient method of in-situ polymerization, using styrene and methyl methacrylate as mixed monomer, Azo diisobutyl cyanide as the initiator, 2-(2ˊ-hydroxyl-5ˊ-methyl phenyl) benzotriazole as the ultraviolet light absorber, styrene-methyl methacrylate copolymer, namely P(St-MMA), was introduced onto the surface of glass by covalent grafting, and finally obtained a self-cleaning glass with superhydrophobic property. The morphology and microstructure of the as-prepared superhydrophobic coating were characterized by SEM, FT-IR, XPS and contact angles. The adhesion strength between the superhydrophobic coating and glass substrate was evaluated by scratch test. At the same time, the thermostability and acid resistance of the as-prepared superhydrophobic coating were also assessed in our work. The results demonstrated that the as-prepared coating had a superhydrophobic surface, and the maximum contact angle, which was prepared at the 9:1 ratio of styrene to methyl methacrylate monomer, was 154.7° and the slighting angle was 5.6°. SEM images indicated that the grafted polymer showed a biomimetic micro-nano structure, and the adhesion between the coating and the glass substrate reached the 5B level, the maximum heat resistance temperature of the hydrophobic coating was 110 °C, and the pH value of the maximum acid resistance was 1. The good hydrophobicity was attributed to the synergistic effect of the hydrophobic coating with low surface energy and the rough surface controlled by the preparing procedure. The as-prepared superhydrophobic coating endowed ordinary glass with good self-cleaning function. And the method could also be extended to the other materials surface, such as metal, ceramics and other polymer materials. It has potential applications in glass curtain wall, bathroom glass, windshield, biological engineering and other fields alternative to traditional glass.

Pyrolysis characteristics and thermal kinetics of expanded polystyrene (EPS) and styrene-methyl methacrylate (St-MMA) copolymer in LFC process

The pyrolysis behaviors of foam patterns have critical influences on fluid morphology and defect formation in Lost Foam Casting (LFC). The pyrolysis behaviors of expanded polystyrene (EPS) and styrenemethyl methacrylate (St-MMA) foams were compared using synchronous thermal analysis (STA), which was performed under argon atmosphere at different heating rates (from 10 to 40 K•min-1). The degradation heat was calculated by integrating DSC curves. Results show that the calculated degradation heat of St-MMA (605.28 J•g-1) was significantly lower than that of EPS (706.71 J•g-1). Furthermore, the non-isothermal iso-conversional method was used to determine the pyrolysis apparent activation energies of EPS and St-MMA, and results show that the activation energy of St-MMA (200.36 kJ•mol-1) was apparently higher than that of EPS (167.92 kJ•mol-1). These calculated results indicate that the weight loss rate of EPS is greater than St-MMA in the pyrolysis process. In addition, the apparent activation energies at various pyrolysis stages demonstrate that the pyrolysis reactions of EPS and St-MMA may involve physical and chemical changes in the decomposition layer of the LFC process.

The effect of copolymer composition, gas content, and temperature on the bubbles nucleation and growth of styrene–methyl methacrylate copolymer/n-pentane foaming process

The foaming process involves three important steps: nucleation, bubble growth, and stability. In the present work, the foaming dynamics of styrene–methyl methacrylate (St-MMA) copolymer/ n-pentane batch foaming system was studied at nonpressurized condition using rapid temperature increasing method. Synthesized copolymers with different compositions were characterized by proton nuclear magnetic resonance analysis and rheological measurements. An in situ foaming observation apparatus was designed, and the foaming dynamics (nucleation and bubble growth behavior) was studied. Dissolved n-pentane contents in all synthesized copolymer compositions at saturation temperatures, near their glass transition temperatures, were determined. The effects of foaming temperature, copolymer composition, and n-pentane content on the foaming dynamics of St-MMA copolymer/ n-pentane system were investigated. The foaming results revealed that the nucleation rate was increased with the increasing foaming temperature, while two other aforementioned parameters were kept constant. The nucleation and bubble growth rate were decreased with increasing MMA units in copolymer composition and increased with dissolved n-pentane content increment in copolymer matrix.

New polymers containing BF2-benzoylacetonate groups. Synthesis, luminescence, excimer and exciplex formation

In the present study, a new synthetic method for the functionalization of polystyrene (PS) and (styrene-methyl methacrylate) copolymer has been developed. Using the new method, polymers containing BF2-benzoylacetonate groups have been obtained through double acylation by acetic anhydride with boron trifluoride. Luminescence of the produced polymers in solutions and films has been studied. Quantum yields of polymer solution luminescence are significantly higher than those of the low-molecular-weight analog – boron difluoride benzoylacetonate. For the polymer, in which styrene fragments are separated by methyl methacrylate groups, at low concentrations of the polymer in solution one observes the monomer luminescence of BF2-benzoylacetonate groups, while at high concentrations – the excimer luminescence. In case of PS-based polymers, in which BF2-benzoylacetonate groups and phenyl rings are not separated, in diluted solutions one observes the fluorescence of the intramolecular exciplexes, while at the concentration increase – the luminescence of intermolecular exciplexes. The ability of excimer formation is responsible for the increased photostability of the produced polymers.

Investigations of variations in surface state of polymer films under structural rearrangements in air and during contact with water

Films of methyl methacrylate–styrene copolymers with the different composition ratios were synthesized; the relaxation processes in a surface film layer were studied when it was in an air environment and during a long-term contact with an aqueous phase. It was shown by analyzing the contact angle and the surface tension of a droplet that the surface structural rearrangement in air after the film deposition was a timeconsuming process developing over tens of days. At the same time, the surface chains in contact with the aqueous phase reoriented in tens of hours. These structural variations observed owing to contact with the aqueous phase were reversible and could be remedied by a subsequent drying in air.

The determination of n-pentane solubility and diffusivity in styrene–methyl methacrylate copolymers via designed apparatus

In this work, styrene–methyl methacrylate copolymer particles were synthesized by suspension polymerization process with different copolymer compositions. A system was designed to measure the solubility and diffusivity of n-pentane in the synthesized copolymers. The designed system consisted of the self-sealing cell equipped to the pressure and temperature controllers. The synthesized copolymer particles were impregnated by n-pentane and their expansion were recorded visually. Furthermore, the solubility and diffusivity of n-pentane in copolymer particles were measured by the same apparatus. The effect of different foaming conditions on the solubility and diffusivity of n-pentane in the samples were examined. It was concluded that the sorption pressure and temperature have contradictory effects on the solubility and diffusivity of n-pentane in styrene–methyl methacrylate copolymers at different sorption pressures. It was concluded that with methyl methacrylate content increment in copolymer, the diffusivity and dissolved n-pentane content in copolymer were reduced.

Laboratory-Scale Studies on Smart Gypsum Composite Boards Incorporated with Nano-Encapsulated Organic Phase Change Material for Thermal Comfort Building Application

AbstractAn experimental study is presented examining the preparation and characterization of a smart gypsum composite board for thermal comfort building application. Composite boards were prepared by mixing 1–30% by weight nano-encapsulated n-octadecane phase change material (PCM) with gypsum to develop gypsum-based building materials with thermal energy storage (TES) capability. The nanocapsules were prepared by encapsulating n-octadecane in nano-sized styrene-methyl–methacrylate copolymer shells using one-step mini-emulsion in situ polymerization. A thermal performance testing device was designed to evaluate the heat storage effect of the resulting gypsum composite. The results indicated that composite boards containing n-octadecane nanocapsules effectively decreased the temperature peak of the experimental test room compared with gypsum board without n-octadecane nanocapsules. This suggested that the composite boards had good thermal energy storage properties. It was also demonstrated that the composit...

The Polarity of poly(methyl methacrylate) Copolymers

Poly (methyl methacrylate) (PMMA) is known as one of the common transparent polymer materials. In this work, pure poly (methyl methacrylate), methyl methacrylate-acrylonitrile copolymer, methyl methacrylate-styrene copolymer was synthesized by bulk polymerization based on the mechanism of free radical polymerization to observe the polarity change of the PMMA after introducing styrene and acrylonitrile monomers. Meanwhile the glass transition temperature, hardness, contact angle and color distribution of the copolymer were measured through polymer temperature deformation analysis experiment, hardness and contact angle measuring instrument.

Preparation of Ag‐Modified (B,P)‐Codoped TiO2 Hollow Spheres with Enhanced Photocatalytic Activity

AbstractA series of TiO2 hollow sphere catalysts with or without nonmetal (B,P) dopants and Ag‐modification were prepared through a sol–gel process with styrene–methyl methacrylate copolymer (PSMMA) microspheres as the template. The samples were characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), laser Raman spectroscopy (LRS), and UV/Vis diffuse reflectance spectroscopy (UV/Vis DRS), and their photocatalytic activities were evaluated by degradation of methylene blue (MB). Both B and P dopants could narrow the band gap of the TiO2 catalyst, and the loaded Ag only played the role of photoelectron transmitter. The two effects of the nonmetal dopants and the loaded Ag improved the photocatalytic activity of the TiO2 hollow spheres. Moreover, the hollow sphere structure and oxygen vacancies were beneficial to photocatalysis. Among all the catalysts prepared, Ag‐modified (B,P)‐codoped TiO2 hollow spheres exhibited the highest photocatalytic activity.

Characterization of Styrene-Methyl Methacrylate Copolymer by Eluent Gradient HPLC

逆相モードの溶媒グラジエント高速液体クロマトグラフィーを用いて，共重合組成の異なるスチレン─メタクリル酸メチル共重合体の溶出挙動を解析した．スチレン含有量が12～91 mol％ のランダム共重合体，及びブロック共重合体，さらにホモポリマーであるポリスチレン（PS）とポリメタクリル酸メチル（PMMA）について，移動相の組成を貧溶媒であるアセトニトリル100％ から良溶媒であるテトラヒドロフラン100％ に直線的に変化させると，PMMA，ついでスチレン含有量の低い共重合体から順次溶出し，最後にPSが溶出した．また，ランダム共重合体とブロック共重合体では溶出挙動が異なり，同じスチレン含有量のブロック共重合体はランダム共重合体よりも遅れて溶出した．組成分布の広い共重合体について，2次元高速液体クロマトグラフィー（HPLC）法を用いて，共重合組成の分子量依存性についても解析を行った．

Solubility and diffusivity of carbon dioxide in St-MMA copolymers

The present study focuses on synthesizing styrene-methylmethacrylate (St-MMA) copolymer particles in a batch reactor using suspension polymerization process at different copolymer compositions. Also for further comparisons, the neat polystyrene (PS) and polymethyl methacrylate (PMMA) were synthesized by the same method. The solubility and diffusivity of supercritical carbon dioxide (scCO2) into the synthesized copolymers at two temperatures (393 and 423)K and pressures in the range from (5 to 12)MPa were measured by a magnetic suspension balance. The Sanchez–Lacombe (SL) equation of state was used to estimate the swelling effect of CO2 on copolymers. The results showed that the solubility and diffusivity of CO2 increased with increasing of CO2 pressure and slightly improved with methyl methacrylate (MMA) content in copolymer. As well as the solubility of CO2 in samples decreased with temperature increment and contrary behavior was observed for diffusivity. Fujita, Maeda and Paul’s diffusion models were combined to estimate the diffusion coefficients for the copolymers and neat polymers.

The effect of expansion conditions on the batch foaming dynamics of St–MMA copolymer

In this study, we synthesized styrene–methyl methacrylate copolymer particles by suspension polymerization process to study the foaming dynamics via visual batch foaming apparatus. The weight ratio of styrene–methyl methacrylate was 53–47. The foaming system consisted of a self-sealing observation cell equipped with two glass windows and a stereo microscope attached with a high-speed digital camera as well as a pressure and temperature controller. The required pentane pressure was supplied by heating a small pentane flask. The synthesized copolymer particles impregnated by pentane and then the foaming dynamics were recorded after a rapid pressure release. The effect of different foaming conditions, such as temperature, impregnation time, and impregnation pressure on the expansion ratio of styrene–methyl methacrylate copolymer was investigated. It was concluded that impregnation pressure, time, and temperature have different effects on the foaming ratio at impregnation pressures lower and higher than 4 bar.

Effect of Composition on Chain Dimensions of Styrene-Methylmethacrylate Random Copolymers under Theta Condition

Rotational-isomeric-state (RIS)-Metropolis Monte Carlo simulations are performed on poly(styrene-ran-methylmethacrylate) random copolymers to study the intrinsic unperturbed (θ-condition) dimensions. Mean-squared end-to-end distance (⟨r2⟩o ), mean-squared radius of gyration (⟨s2⟩o ), and characteristic ratio (Cn) have been calculated for these copolymers constituted by different overall chemical compositions (styrene fractions 0.29, 0.56, and 0.70). Calculations were carried out with chains of 500 repeating units. With an increase in the styrene content there is an increase in ⟨r 2⟩ o, `, and Cn, in agreement with experimental observations. An increase in the fraction of trans conformational states in the backbone torsion angles is found to be responsible for the exhibited chain expansion behavior. The dimensions calculated by the Monte Carlo simulations agree well with experimental values reported in the literature.

Characterization of synthetic copolymers by interaction polymer chromatography: Separation by microstructure

Gradient elution of synthetic polymers has been studied both theoretically and experimentally using normal and reversed-phase HPLC systems. An accurate equation describing the gradient elution of polymer-homologous series in the context of continuous random-flight model of a flexible polymer chain interacting with attractive surface of the porous material has been derived and experimentally verified against a series of narrow polystyrene standards. Both the theory and the experiment predict the existence of molar mass-independent gradient elution at critical point of adsorption (CPA). The extension of the theory to synthetic copolymers predicts the existence of the CPA for statistical copolymers and describes its dependence on chemical composition and microstructure (blockiness) of the polymer chains. One of the important theoretical conclusions is that blockiness always increases the retention, so that blockier polymer chains elute later than their more random counterparts with the same chemical composition. This prediction has been confirmed experimentally using block and statistical styrene-methylmethacrylate copolymers. Block copolymers do not have CPA and always elute between critical points of the corresponding homopolymers. The retention depends on the polymer molar mass and increases with the length of the blocks from a stronger absorbing monomer. These findings provide theoretical and experimental bases for separation of statistical and block copolymers by chemical composition and microstructure of polymer chains.

Microencapsulation of PCMs with a styrene-methyl methacrylate copolymer shell by suspension-like polymerisation

The microencapsulation of phase change materials (PCMs) by a suspension copolymerisation of styrene (St) and methyl methacrylate (MMA) has been studied. The influence of the monomers/paraffin and the MMA/St mass ratio on the encapsulation process and the physical properties of the resulting microcapsules has been studied. The thermal properties, morphology, chemical composition and particle size distribution of the microcapsules were characterised by differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), environmental scanning electron microscopy (ESEM), optical microscopy (OM), Fourier transform infrared spectroscopy (FT-IR) and low angle laser light scattering (LALLS). It was found that the MMA/St mass ratio has a marked influence on the polymerisation rate, affecting the con

Recycling of poly(methyl methacrylate) scrap in the styrene–methyl methacrylate copolymer cast sheet process

Poly(methyl methacrylate), PMMA, scrap generated during the casting process for PMMA cast sheet is an industrial waste stream, which has a high impact on the PMMA production cost and environment. This paper presents an alternative way to reduce the processing cost of PMMA cast sheet and decrease industrial waste by using styrene (S) as a co-monomer with methyl methacrylate (MMA) monomer, in conjunction with recycling of PMMA scrap in the S–MMA copolymer cast sheet process. The influence of factors, such as the concentrations of S and PMMA scrap, on the preparation of S–MMA copolymer cast sheet mixed with PMMA scrap was investigated. The characterization of basic copolymer composition, the physical, and the mechanical properties of the final products were examined. The results show that it is possible to recycle PMMA scrap into the S–MMA copolymer cast sheet process, and it does not affect the desired properties of final copolymer products. Finally, the environmental impact of recycling the PMMA scrap was evaluated by using the life cycle inventory (LCI) data for material grouping according to environmental and material properties. The results show the decrease of natural resource consumption and pollutions (65 tons/year of coal, 147.5 tons/year of crude oil, 180 tons/year of natural gas, 825 tons/year of CO 2, 4 tons/year of NO x , 4.5 tons/year of SO x , 3.25 tons/year of CH 4, 0.8 tons/year of dust, 88 × 10 6 mg/year of BOD, 10,000 m 2 of land conversion) with respect to the recycling of 5% acrylic waste scrap in the S–PMMA cast sheet production process. Moreover, 5% of recyclable PMMA scrap can reduce the costs of raw material, waste disposal, processing, and transportation, which are approximately 6–7% saving of the total cost.