Grafted Poly Methyl Methacrylate Research Articles

Structure and Electrical Properties of Polymer Electrolyte Based on Plasticized Chitosan Grafted Polymethyl Methacrylate (Ch-g-PMMA)- Magnesium Triflate for Electrochemical Double Layer Capacitor

Polymer electrolytes have received much attention as materials used in batteries, supercapacitors, sensors and solar cells. Most of the polymer electrolytes reported are based on synthetic polymer, therefore it is difficult to recycle as it has poor degradability and ends up being a waste. In recent years, biopolymers gained much interest in replacing environmentally unfriendly polymers. Various studies have been done to accomplish polymer electrolytes with high conductivity and long-term safety. This study’s objective is to prepare plasticized Ch-g-PMMA-based polymer electrolyte by introducing the magnesium triflate salt and glycerol plasticizer. The grafted polymer of Ch-g-PMMA was prepared using gamma (γ) radiation. The grafted polymer of Ch-g-PMMA with 0.4 g of Mg(Tf)2 and different concentrations of glycerol has been prepared by using the solution casting technique. To achieve this study, the prepared plasticized Ch-g-PMMA-Mg(Tf)2 polymer electrolytes are characterized by XRD, FTIR, EIS and LSV techniques. XRD was carried out to determine the change in crystallinity and the amorphous structure of the plasticized Ch-g-PMMA-Mg(Tf)2 polymer. FTIR reveals the occurrence of complexation between Ch-g-PMMA polymer, Mg(Tf)2 salt and glycerol plasticizer. The grafted Ch-g-PMMA-Mg(Tf)2 was added with different concentrations of glycerol from 0 to 50 wt%. The Ch-g-PMMA-Mg(Tf)2 polymer electrolyte with 50 wt% of glycerol shows the highest ionic conductivity of 1.50×10−4 S·cm−1 compared with other samples. The increase in mobility of ions and the number of charge carriers has enhanced ionic conductivity. Based on the LSV analysis, the highest conducting Ch-g-PMMA-Mg(Tf)2 polymer with 50 wt% of glycerol was found electrochemically stable up to 3.2 V. The goal of this study is to determine the structure and electrical properties as well as the window stability of plasticized Ch-g-PMMA-Mg(Tf)2. The best outcome was produced by adding the 50 wt% of glycerol into the Ch-g-PMMA-Mg(Tf)2 which increased further by 1 order of magnitude. HIGHLIGHTS The ionic conductivity of the Ch-g-PMMA increases by introducing magnesium triflate salt and glycerol plasticizer which enhance the amorphous state and decrease the crystallinity The prepared plasticized Ch-g-PMMA-Mg(Tf)2 polymer electrolytes are characterized by XRD, FTIR, EIS and LSV techniques The highest ionic conductivity are obtained by added 50 wt% glycerol to the grafted polymer CH-g-PMMA-Mg(Tf)2 which is 1.50×10−4 S·cm−1 GRAPHICAL ABSTRACT

Novel crystalline reduced graphene oxide/adhesive nanocomposites for enhanced electrical, thermal, dielectric properties and electromagnetic energy absorption application

At present times electromagnetic (EM) pollution is increasing due to a lot of progress and achievements in the electronics field. There is a dire need to develop materials that have greater EM energy absorption/emission properties. We report here the synthesis of a nanocomposite of carbonaceous material, reduced graphene oxide (rGO) with Chloroprene (CP) grafted polymethyl methacrylate (CP-g-pMMA), i.e. rGO/CP-g-pMMA. FTIR confirms the grafting of Chloroprene rubber and the presence of rGO. XRD shows the crystallinity of rGO alone and in the composites as well. SEM images showed smooth texture for neat polymer while nanocomposite showed a leafy appearance of the reduced graphene oxide (rGO). The viscosity of pure CP was 3740 cps while CP-g-pMMA was 1644 cps. A slight decrease was observed after the addition of rGO. Enhancement in thermal properties from 264 °C to 269 °C showed that the composites were thermally more stable than the virgin CP and CP-g-pMMA. The permittivity and alternating current conductivity were checked by Radio Frequency (RF) impedance and material analyzer in the range of (1–1000 MHz) X-band and (1–3 GHz) S-band. The nanocomposites showed the lowest percolation (0.32 vol. %) yet reported. The nanocomposites showed low real and absolute permittivity. The electrical and permittivity analysis of the rGO/CP-g-pMMA nanocomposites revealed that they can be potential candidates for their applications in electronic devices as an absorber.

PMMA-Grafted Calcium Sulfate Whiskers for Applications as Fillers in PVC.

Calcium sulfate whiskers (CSWs) were hydroxylated with a sodium hydroxide (NaOH) solution and isolated for subsequent treatment with an ethanolic 3-(methacryloxy)propyltrimethoxysilane (KH570) solution to introduce C=C double bonds on the CSWs’ surfaces. Then, CSW-g-PMMA was prepared by grafting polymethyl methacrylate (PMMA) onto the surface of modified CSW using in situ dispersion polymerization. The CSW-g-PMMA was used as a filler and melt-blended with polyvinyl chloride (PVC) to prepare PVC-based composites. The surface chemical structure, PMMA grafting rate, and hydrophobic properties of CSW-g-PMMA were analyzed using X-ray diffraction, diffuse reflectance Fourier-transform infrared spectroscopy, thermogravimetric analysis, and water contact angle measurements, respectively. The effects of the CSW-g-PMMA filler on the mechanical properties of the CSW-PMMA/PVC composites were also investigated. The results showed that NaOH treatment significantly increased the number of hydroxyl groups on the surface of the CSWs, which facilitated the introduction of KH570. PMMA was successfully grafted onto the KH570 with a grafting rate of 14.48% onto the surface of the CSWs. The CSW-g-PMMA had good interfacial compatibility and adhesion properties with the PVC matrix. The tensile, flexural, and impact strengths of the CSW-g-PMMA/PVC composite reached 39.28 MPa, 45.69 MPa, and 7.05 kJ/m2, respectively, which were 38.55%, 30.99%, and 20.10% higher than those of the CSW/PVC composite and 54.52%, 40.80%, and 32.52% higher than those of pure PVC, respectively. This work provides a new method for surface modification of inorganic fillers, resource utilization, and high value-added application of CSWs from phosphogypsum.

Customized polymethylmethacrylate cranioplasty using a low-cost 3-dimensional printed mold

Introduction. Significant cranial defects result from a decompressive craniectomy following head trauma, malignant brain edema, intracranial hemorrhage, or resection of tumor affected bone. Unrepaired cranial defects are not just a tremendous esthetic problem. The underlying brain is unprotected, prone to injury, and this state can lead to the so-called ?syndrome of the trephined? with mood instability, headaches, and even a neurological deficit. Currently, there is no widely accepted uniform technique of cranial vault shape restoration. Combining 3D technology with the use of polymethylmethacrylate is a challenging field that can bring good functional and aesthetic results and, in the case of smart design, become efficient, low-cost technology. We offer a possible solution to a problem that would be acceptable in neurosurgical practice. Case outline. We present a 37-year-old male patient with a massive hemicranial defect as a consequence of previous decompressive craniectomy following severe craniocerebral injury the previous year. Together with engineers from the appropriate 3D modeling studio, we have designed a two-part mold by laser printing technology using biocompatible advanced polyamide. We made a customized polymethylmethacrylate graft intraoperatively using this mold and achieved good aesthetic results. Conclusion. Reports of 3D printing assisted cranioplasties are growing, describing different techniques and cost- estimation. We hope to introduce a low-cost and simple method for repairing a skull defect.

Transparent radiative cooling films containing poly(methylmethacrylate), silica, and silver

Window is the least energy-efficient part of buildings or cars; however radiative cooling, as an efficient energy-zero technology, is rarely used in window films of buildings or cars. Therefore, we in this work fabricated a transparent dual-layer film for daytime radiative cooling, which contained a layer of polymethyl methacrylate (PMMA) uniformly mixed with modified silica nanoparticles (SiO2 NPs) and a layer of silver. The dispersion of the modified SiO2 NPs in PMMA was notably improved through in-site grafting PMMA, which resulted in a high transparency of the radiative cooling film even at a high filling fraction of SiO2 (20 wt%). Owing to the strong broadband IR absorbance/emittance (εAW = 94.3%) and high sunlight reflectance (ρ ≈ 50%), the dual-layer film possessed a high cooling capacity and could achieve an average temperature drop of 1.4 °C than pure PMMA film in the daytime outdoor cooling measurement. In the simulated automotive cooling test, the dual-layer film cooled the interior space up to 6 °C below ambient temperature during peak solar hours. The excellent optical property and cooling capability exhibit a promising application of building and car windows for cooling their interior spaces.

Comparative Study between Fusion and Non-Fusion Techniques in Anterior Cervical Discectomy: Bone Cement Versus Cervical Cage

Abstract Background: A prospective comparative study between fusion and non-fusion techniques in anterior cervical discec-tomy (ACD) evaluating the results achieved using polymeth-ylmethacrylate (PMMA) as a non-fusion and cervical cage (PEEK) as a fusion following single level ACD. Patients and Methods: A total of 40 patients, divided in to two groups of 20 patients each, group (A); having PMMA used for disc replacement and group (B) cervical (PEEK) cage placement after ACD. Results: Of both groups are evaluated regarding: (1) Clinical outcome according to Odom's criteria (2) Radiological outcome and inter body fusion, (3) Simplicity and postoperative morbidity of each procedure and (4) Complications related to each technique. Patients were followed up for a mean period of 10 months. Group (A) presented excellent and good clinical outcome in 85% at 6 months and 90% at 12 months. Radio-logical none fusion was noticed in 80% of patients and partial fusion occurred in 20% of cases at 12 months postoperative interval cage migration in 5% (one patient) into adjacent vertebral bodies which needed surgical removal and replaced by cage after causing partial collapse of the disc space height. No other graft related complications, progressive deformity or instability were reported. Group (B) achieved 90% excellent and good clinical outcome at 6 and 12 months respectively. Fusion rate of 85% at 6 months and increased to 95% at 12 months. No other cage related complications were reported. Conclusion: Clinical outcome in both group is related to the surgical decompression technique and preoperative neu-rological status of the patients e.g. cervical spondylotic myelopathy (CSM), cervical spondylotic radiculopathy (CSR) or both than to the use of either disc replacement by fusion (PEEK) cage or non fusion by bone cement (PMMA). The use of interbody fusion cage is preferred owing to their ability to function as load-sharing devices and to adequately fix the spine and increase segmental stiffness thus achieve acceptable fusion rate and low complication when compared with PMMA graft.

Synthesis of chitosan grafted polymethyl methacrylate nanopolymers and its effect on polyvinyl chloride membrane for acetone recovery by pervaporation

In comparison to conventional nanoparticles biopolymer like chitosan based nanoparticles will be of much lower cost, non-toxic and more compatible with polymer membranes. As a cationic polymer surfactant chitosan is able to generate polymer nanoparticles during emulsion polymerization of methyl methacrylate. Accordingly, the organophilicity of polyvinyl chloride (PVC) membrane was significantly improved by incorporating chitosan grafted polymethyl methacrylate (PMMA) nanopolymers(NPs) prepared by emulsion polymerization. The NPs and the PVC-NP blend membranes were characterized. The chitosan: MMA wt. ratio and the wt.% of NP in PVC were optimized by a 5-level factorial design. The membranes prepared from i) PVC, PVC blended with 6.5 wt.% each of ii) chitosan, iii) PMMA and iv) NP showed a pervaporative flux (kg/m2h)/acetone selectivity of 0.439/24.31, 0.477/21.56, 0.461/23.41 and 0.502/27.96, respectively for 5.6 wt.% acetone in feed. The sorption and pervaporation data showed close fitting to ENSIC and six-parameter solution-diffusion model, respectively.

Biomechanical Comparison of Polymethylmethacrylate Augmentation Methods in Failed Pedicle Screw Revision.

To compare biomechanical results between different polymethylmethacrylate (PMMA) augmentation methods on failed lumbar pedicle screw models of animal vertebrae. Thirty lumbar vertebrae were harvested from six calves, and their bone mineral density was measured. 60 Polyaxial pedicle screws were inserted to all vertebrae. Pull-out tests were performed to all specimens on an Instron machine. The specimens were randomly divided into four groups. The same screws used in primary screwing process were labeled and used in revision. Screws in the first group were augmented by injecting PMMA into the failed screw hole with a syringe; screws in the second group by inserting bone graft and roll-shaped PMMA, screws in the third group by inserting bone graft and injecting PMMA with a syringe; and the fourth group by inserting bone graft and injecting PMMA through a fenestrated pedicle screw. The pull-out strength (POS) results of all specimens were recorded and compared with statistical analyses. The mean BMD of the vertebrae was 1.31 ± 0.225 g/cm < sup > 2 < /sup > and no significant difference was found between the groups (p > 0.05). The mean POS of the primary screws in the first, second, third, and fourth groups were 2166,5 N/m < sup > 2 < /sup > , 2183,5 N/m2, 2508,5 N/m < sup > 2 < /sup > , and 2005c N/m < sup > 2 < /sup > respectively. After the augmentation, the mean POS in the first, second, third and fourth groups were 3839 N/m < sup > 2 < /sup > , 2874 N/m < sup > 2 < /sup > , 2929 N/m < sup > 2 < /sup > and 3826 N/m < sup > 2 < /sup > respectively. No statistical difference was found between the groups in post-revision POS values (p > 0.05). There was no significant statistical difference found in POS between the augmentation methods.

In situ synthesis of polymer-modified boron nitride nanosheets via anionic polymerization

Owing to their inherent inertness, covalent functionalization of hexagonal boron nitride nanosheets (BNNSs) proves very difficult, greatly limiting their potential applications. Herein, we report an one-pot in-situ synthesis of polymer-modified boron nitride nanosheets via reductive functionalization. Negatively charged boron nitride nanosheets, generated by a smooth reductive treatment in an electron-rich environment, are directly employed as an initiator to trigger in situ anionic polymerization of methyl methacrylate (MMA) monomers, avoiding the use of complex initiators. The successful grafting of polymethyl methacrylate (PMMA) chains onto BNNS surfaces is evidenced by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The functionalized boron nitride nanosheets formed via B-C bonding through this facile “grafting from” method exhibit excellent dispersibility in acetone. When used as a filler, the material shows remarkable mechanical reinforcement for polymeric composites. The reductive charge provides a simple and scalable route for versatile chemical modifications of BNNSs to tailor surface properties of BNNSs, which will find important applications in sensors, catalysis, composite coating, bioimaging and drug delivery etc.

Dual‐phase polyphenylene oxide membranes with copolyimide branched modifiers

AbstractPoly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) membranes are attractive due to high permeability for gases; however, the selectivity of these membranes is insufficient. In this work, the gas selectivity was improved without significant loss of the permeability. For this purpose, PPO was modified via incorporation of the branched copolyimide filler–grafted copolyimide (PI‐g‐PMMA) with polymethyl methacrylate (PMMA) side chains. Two series of mixed self‐supporting PPO/PI‐g‐PMMA films (with variation of the filler content) were prepared and studied as gas separation membranes. The length of the polymide (PI) chain and the density of PMMA grafting were the same in both series, however, in one series the grafted chains contained 50 MMA units, and in the other 150 units. The intermolecular interactions between the PPO matrix and the PI‐g‐PMMA fillers were investigated using viscometry, infrared (IR) spectroscopy, and scanning electron microscopy. The compatibility of the polymer components is limited; however, for both series, the contents of the respective filler are found, which ensures phase segregation only in a microscale. Therefore, the mechanical properties of the films allow their use as gas separation membranes. It is shown that the degree of the segregation as well as the mechanical and gas transport properties of the membranes depend on the length of the PMMA chains, and the membranes with filler‐containing shorter branches (50 MMA units) show better selectivity.

Stability of PMMA-grafted/Ti hybrid biomaterial interface in corrosive media

Abstract The stability of interfaces between polymethyl methacrylate (PMMA) and titanium (Ti) are tested in a Ringer solution that is an aggressive medium usually used for biomaterial evaluation. The devices are PMMA-grafted/Ti elaborated via a “grafting-from” method involving three steps, the alkali activation of Ti sheets, their functionalization with an initiator of polymerization through a phosphonate anchoring group and the growth of PMMA brushes. Electrochemical characterizations demonstrate that the stability of the PMMA-grafted/Ti interface in biological medium is satisfactory and that the grafting of PMMA is even acting as a protective barrier for titanium. Indeed, PMMA-grafted/Ti remains passive in Ringer solution until at least +3 V/SCE (saturated calomel electrode), even under inflammatory conditions, while localized corrosion was measured on as-received titanium in similar conditions. This protecting role is attributed to the grafted interface, since spin-coated PMMA does not decrease the corrosion sensitivity of titanium.

Fronto-nasal cranioplasty using polymethylmethracylate - case report

Patients who present a background of bone defects seek for harmonic facial contours through surgical rehabilitation. To facilitate the maxillofacial reconstruction, there are two groups of grafts that can be used: the bone and alloplastic materials, such as the polymethyl methacrylate (PMMA), which is one of the alloplastic materials usually used by surgeons in facial rehabilitation. The aim of this study is to present a clinical report about a frontal cranioplasty using PMMA and compare its use with other materials in the literature. A male patient, 35 years old, ASA I, had a motorcycle accident, and a physical examination showed a sinking in the frontal region, deviation of right nasal dorsum and restriction of air passage through the left nostril. At the imaging examination, it was found suggestive signs of naso-orbit-ethmoid fracture and external table fracture in the middle region of the frontal bone. The patient was submitted to a surgical procedure for reconstruction of bone defect and a PMMA graft was used in the frontal bone region. PMMA is usually used because of its ease of adaptation to the bone, reduction of time of the surgery and decrease of blood loss and possibility of infection. PMMA is an attractive alternative for maxillofacial reconstructions.

Two-Stage Cranioplasty: Tissue Expansion Directly over the Craniectomy Defect Prior to Cranioplasty.

Performing a skull reconstruction for a long-term existing large cranium defect usually needs either skin enhancement or skin flaps and cranioplasty. This procedure can be accompanied with aesthetic and functional complications. The presented case describes a 27-year-old man in need of a cranial reconstruction following decompressive craniectomy as treatment for severe traumatic brain injury. Autologous cranioplasty after decompressive craniectomy failed due to bone flap infection. Because of cognitive behavioral problems, a protective helmet needed to be worn in awaiting cranioplasty. The final titanium cranioplasty was placed subsequent to scalp expansion. The expansion was realized by placing a temporary and custom-made polymethylmethacrylate (PMMA) plate over the defect with a tissue expander on top of it, using the existing scar and skull defect. Our reported technique avoids additional skin flap creation and accompanied complications such as additional scalp and bone damage. In cognitive damaged patients who need to wear a helmet constantly, this simple method provides, concurrently, protection of the brain and tissue expansion. We demonstrate a successful novel technical manner to provide scalp enhancement by positioning a temporary PMMA graft over the skull defect and placing the tissue expander on top of it.

Synthetic bone graft versus autograft or allograft for spinal fusion: a systematic review.

The purpose of this review was to compare the efficacy and safety of synthetic bone graft substitutes versus autograft or allograft for the treatment of lumbar and cervical spinal degenerative diseases. Multiple major medical reference databases were searched for studies that evaluated spinal fusion using synthetic bone graft substitutes (either alone or with an autograft or allograft) compared with autograft and allograft. Randomized controlled trials (RCT) and cohort studies with more than 10 patients were included. Radiographic fusion, patient-reported outcomes, and functional outcomes were the primary outcomes of interest. The search yielded 214 citations with 27 studies that met the inclusion criteria. For the patients with lumbar spinal degenerative disease, data from 19 comparative studies were included: 3 RCTs, 12 prospective, and 4 retrospective studies. Hydroxyapatite (HA), HA+collagen, β-tricalcium phosphate (β-TCP), calcium sulfate, or polymethylmethacrylate (PMMA) were used. Overall, there were no differences between the treatment groups in terms of fusion, functional outcomes, or complications, except in 1 study that found higher rates of HA graft absorption. For the patients with cervical degenerative conditions, data from 8 comparative studies were included: 4 RCTs and 4 cohort studies (1 prospective and 3 retrospective studies). Synthetic grafts included HA, β-TCP/HA, PMMA, and biocompatible osteoconductive polymer (BOP). The PMMA and BOP grafts led to lower fusion rates, and PMMA, HA, and BOP had greater risks of graft fragmentation, settling, and instrumentation problems compared with iliac crest bone graft. The overall quality of evidence evaluating the potential use and superiority of the synthetic biological materials for lumbar and cervical fusion in this systematic review was low or insufficient, largely due to the high potential for bias and small sample sizes. Thus, definitive conclusions or recommendations regarding the use of these synthetic materials should be made cautiously and within the context of the limitations of the evidence.

Synthesis, characterization and application of polymethyl methacrylate grafted oatmeal: a potential flocculant for wastewater treatment.

The studies report the synthesis of novel graft copolymer of oatmeal. Polymethyl methacrylate grafting was carried out on oatmeal backbone via ‘microwave assisted’ approach. The graft copolymers were optimized by varying monomer and CAN concentration. The synthesized graft copolymers were characterized by intrinsic viscosity, FTIR, TGA, SEM, Elemental Analysis, number average molecular weight and solubility. All the grades of graft copolymers were assessed for its potential application as a flocculant in 1 wt% coal-fine suspension, 0.25 wt% kaolin suspension and municipal wastewater using standard ‘jar test’ protocol. The flocculation efficacy of synthesized graft copolymers was compared with commercially available coagulant (alum) in 1 wt% coal-fine and 0.25 wt% kaolin suspensions and was found to exhibit better potential as a flocculant than alum and oatmeal. Among diverse grades of graft copolymers, OAT-g-PMMA-5 exhibits higher percentage grafting, intrinsic viscosity and flocculation efficacy for removal of heavy metal ions, suspended particles and organic loads from wastewater.

A benzimidazole-based conducting polymer and a PMMA–clay nanocomposite containing biosensor platform for glucose sensing

Development of materials composed of polymer–clay nanocomposites (PCN) and conducting polymers attracts great interest and preferred in various applications. Hereby, polymethylmethacrylate (PMMA) layered silicate nanocomposites were prepared by in-situ suspension polymerization by grafting PMMA with laponite using a suitable grafting agent. The properties of the as-synthesized PCN materials are characterized by differential scanning calorimetry (DSC), thermal gravimetry analysis (TGA) and gel permeation chromatography (GPC). A conducting polymer; poly(4-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-7-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7-yl)-2-benzyl-1H-benzo[d]imidazole) (poly(BIPE)) and a PMMA–clay nanocomposite with 2-(methacryloyloxy) ethyltrimethylammonium chloride (MTMA) modifier were examined as a platform for biomolecule deposition. Glucose oxidase (GOx, β-d-glucose: oxygen-1-oxidoreductase, EC 1.1.3.4) was chosen as the model enzyme to prepare a scaffold for glucose sensing. Three different sensing strategies; PCN/GOx, poly(BIPE)/GOx and PCN/poly(BIPE)/GOx were analyzed and their biosensor performances were discussed. Surface morphology of the modified electrodes was characterized by scanning electron microscopy (SEM) technique. Electrochemical responses of the enzyme electrodes were monitored at −0.7V vs. Ag reference electrode by monitoring oxygen consumption in the presence of glucose. After optimum conditions were determined, kinetic and analytical parameters; KMapp, Imax, LOD and sensitivity were investigated for each sensing platform.

A corrosion-protective coating based on a solution-processable polymer-grafted graphene oxide nanocomposite

A new type of solution-processable graphene coating has been synthesized by grafting polymethylmethacrylate (PMMA) brushes on graphene oxide (GO) via surface-initiated atom transfer radical polymerization (ATRP). One major finding is that the PMMA-grafted GO nanocomposite exhibits synergistic properties of both building blocks, i.e., permeation inhibition of GO and solubility of PMMA in a variety of solvents, which makes it compatible with commonly used coating methods to form uniform coatings with controlled thickness. Our results demonstrate that PMMA-grafted GO coating can effectively block charge transfer at the metal–electrolyte interface and prevent corrosion of the copper substrate under aggressive saline conditions.

Effect of the molecular chains grafted on graphene nanosheets on the properties of poly(l‐lactic acid) nanocomposites

We prepared thermally reduced graphene oxide (TRG) grafted with polymethyl methacrylate (PMMA) and polyvinyl acetate (PVAc) (TRG‐g‐PMMA and TRG‐g‐PVAc) by γ‐ray irradiation‐induced graft polymerization and studied their effects on poly(l‐lactic acid) (PLLA) nanocomposites. PMMA and PVAc chains were proved to be grafted on the TRG surface successfully. TRG‐g‐PMMA and TRG‐g‐PVAc was found to restrict the crystallization behavior of PLLA compared with TRG. Moreover, tensile‐test results showed that TRG‐g‐PMMA and TRG‐g‐PVAc could enhance the elongation at break of PLLA nanocomposites without reducing the tensile strength and modulus compared with TRG, which indicated that the grafting of PMMA and PVAc chains on TRG could improve the toughness of PLLA nanocomposites. POLYM. COMPOS., 38:5–12, 2017. © 2015 Society of Plastics Engineers

Gas separation performance of thin film nanocomposite membranes incorporated with polymethyl methacrylate grafted multi-walled carbon nanotubes

Recently, membrane technology has gained much momentum in the field of carbon capture and storage due to its practicality and energy efficiency. In this work, thin film nanocomposite (TFN) membranes embedded with polymethyl methacrylate (PMMA) grafted multi-walled carbon nanotubes (MWNTs) were successfully fabricated. The effects of nanofillers modification on the resultant membranes morphology and gas separation performance have been highlighted. TFN incorporated with milled PMMA grafted MWNTs showed 29% increment in CO2 permeance at 70.5 GPU with 47% and 9% enhancement in CO2/N2 and CO2/CH4 selectivity, respectively compared to the thin film composite counterpart. While the improvement was mainly attributed to the presence of highly diffusive channels upon the addition of MWNTs, PMMA grafting also played an important role in ensuring well nanofillers dispersion and good compatibility with the polyamide thin film. Uncovering the construct of membrane fabrication could pave facile yet versatile way for the development of effective membranes for greenhouse gas removal.

Synthesis and Properties of Electroactive Polyaniline-Graft Polymethyl Methacrylate Copolymer by Atom Transfer Radical Polymerization

In this research, N-substituted polyaniline was synthesized by chlorine-terminated chloroacetyl chloride incorporation and methylmethacrylate polymerization done onto the leucoemeraldine. The authors prepared polyaniline-graft-polymethylmethacrylate copolymer by methylmethacrylate ATRP using polyaniline macroinitiator. First, polyaniline was prepared by chemical oxidation. The macroinitiator was synthesized via reaction of leucoemeraldine's nitrogen with chloroacetyl chloride. Macroinitiator and graft copolymer were characterized by FT-IR and 1H-NMR. SEM and AFM images showed the growing of poly methylmethacrylate chains on polyaniline backbone. Solubility test revealed that polyaniline-graft-poly(methylmethacrylate) was in some organic solvents. CV study confirmed this copolymer was electroactive. Elemental analysis determined the amount of grafting polymethylmethacrylate on leucoemeraldine.