Preparation Of Graft Copolymers Research Articles

Oil absorbent based on lauryl methacrylate grafting onto cellulose of water hyacinth (Eichhornia crassipes)

AbstractIn this article, a novel oil‐absorbent polymer was synthesized by graft polymerization of lauryl methacrylate (LMA) onto water hyacinth (WH) using 2,2′‐azobisisobutyronitrile (AIBN) as initiator and divinyl benzene (DVB) as a crosslinking agent. The effects of initiator content, LMA content, reaction temperature, reaction time, and crosslinker content on the superabsorbent polymer were investigated. The prepared graft copolymer WH‐g‐LMA was analyzed using FTIR, SEM, XRD, and TGA. In the presence of the better cross‐linker DVB (1.5%) and contact time of about 25 min, the maximal Q (oil sorption capacity) of co‐polymer towards crude and Soybean oils is 23.68 and 25.72 g g−1, respectively. The Q is reduced when sorbent dosage increased, but it increases with increasing the temperature and reaches a maximum of 40 °C. The reusability of co‐polymer is characteristic of 7 sorption/desorption cycles.

A new method for synthesis of modified cellulose‐graft‐poly(acrylic acid) copolymer using 4‐cyano‐4‐[(phenylcarbothioyl)solfanyl]pentanoic acid to serve as RAFT agent

AbstractIn this study, cellulose was first treated with 4‐cyano‐4‐((phenyl carbonothioyl)solfanyl) pentanoic acid to serve as the reversible addition‐fragmentation chain transfer polymerization (RAFT) agent, then the controlled grafting polymerization of acrylic acid was successfully performed. A well‐defined, cellulose‐graft‐acrylic acid copolymer (Cell‐g‐PAA), has been prepared by RAFT polymerization technique using three different approaches: RAFT agent was prepared by substitution of dithiobenzoate magnesium bromide with 4,4'‐azobis(4‐cyanopentanoic acid) in ethyl acetate as a solvent, mediated cellulose (Cell) block as the macromolecular Cell‐RAFT agent and (cellulose‐co‐acrylic acid) copolymer with alternating sequence. The resulting (Cell‐RAFT) for “living” free radical polymerization was then heated in the adjacent acrylic acid monomer for the development of the controlled graft copolymer onto cellulose. The structures of the intermediate, graft copolymer were investigated by FT‐IR, DSC, 1H NMR, scanning electron microscopy, and thermo gravimetric. The results demonstrate that the preparation of graft copolymers was successfully confirmed. This approach would provide an extensive classification of molecular designs to obtain modern types of tailored hybrid materials derived from natural polysaccharides and synthetic polymers. Also, using a macro‐initiator is an excellent method for synthesizing new materials.

High-performance and functional fully bio-based polylactic acid/polypropylene carbonate blends by in situ multistep reaction-induced interfacial control

Using a solvent-free radical grafting technique, glycidyl methacrylate (GMA) and maleic anhydride (MAH) were used as functionalized graft monomers, styrene (St) as a copolymer monomer, and grafted onto polylactic acid (PLA). A series of PLA-g-(GMA/MAH-co-St) graft copolymers were prepared by adjusting the GMA/MAH ratio. Subsequently, the prepared graft copolymers were used as a compatibilizer with PLA and polypropylene carbonate (PPC) for melt blending to prepare PLA/PPC/PLA-g-(GMA/MAH-co-St) blends. The effects of changes in the GMA/MAH ratio in the graft copolymer on the thermodynamics, rheology, optics, degradation performance, mechanical properties, and microstructure of the blend were studied. The results found that GMA, MAH, and St were successfully grafted onto PLA, and the PLA-g-(GMA/MAH-co-St) graft copolymer obtained from the reaction had a good toughening effect on the PLA/PPC blend system, which significantly improved the mechanical properties of the PLA/PPC/PLA-g-(GMA/MAH-co-St) blend without reducing its degradation performance, resulting in a biodegradable blend material with excellent comprehensive performance. In the PLA-g-(GMA/MAH-co-St) grafting reaction system, when GMA/MAH = 1.5/1.5 (w/w), the grafting degree of the graft copolymer increased most significantly, from 0.83 phr to 1.51 phr. This composition of graft copolymer can effectively improve the compatibility between PLA and PPC. The resulting PLA/PPC blend can maintain good melt flow properties (MFR of 14.51 g/10 min), high transparency, and low haze (light transmittance of 91.56 %, haze of 20.5 %), while significantly improving its thermal stability (T95%, Tmax, and Et increased by 12.87 °C, 20.33 °C, and 32.00 kJ/mol, respectively). Moreover, when introducing PLA-g-(GMA/MAH-co-St) (GMA/MAH = 1.5/1.5 (wt/wt)) graft copolymer into the system, the toughness of the PLA/PPC/PLA-g-(GMA/MAH-co-St) blend system is optimal, with the notch impact strength and fracture elongation increasing to 184.6 % and 535.4 % of the PLA/PPC blend, respectively, at which point the fracture surface of the impact sample shows a wrinkled fracture feature indicative of toughness.

Copper oxide nanocomposite particles supported on sodium alginate-g-polyallylamine based reduced graphene oxide: An efficient electrochemical sensor for sensitive detection of cadmium ions in water

A highly sensitive and selective electrochemical sensor, sodium alginate-g-polyallylamine/reducedgrapheneoxide/CuO nanocomposite particles (SAGPMRGO@CuO NPs) has been synthesized for the detection of Cd2+ ions in the aqueous environment. The graft copolymer/reduced graphene oxide supported CuO nanocomposite particles are prepared through bioreduction of graphene oxide by a novel synthesized graft copolymer sodium alginate-g-PAAM (SAG-g-PAAM) to reduced graphene oxide (SAGPMRGO) followed by using it as both a reductant and a stabilizing agent to obtain SAGPMRGO@CuO hybrid nanocomposite particles. The graft copolymer is prepared via free radical solution phase graft copolymerization technique. The graphene oxide (GO) is prepared by the oxidation of graphite using modified Hummer's method. The prepared nanocomposite particles are characterized by UV-VIS, FTIR and Raman spectroscopy, powder X-ray diffraction (PXRD), HRTEM-EDS, FESEM, XPS and DLS analysis with zeta potential measurement in colloidal suspension. The prepared graft copolymer is characterized by 1H and 13C NMR spectroscopy, PXRD and FESEM analysis and the SAMPGRGO is characterized by UV-VIS and Raman spectroscopy, PXRD and FESEM analysis. The CuO nanocomposite particles are spindle shaped with an average particle size ranges from 15.6 nm to 32.1 nm and are well polydispersed. Metal ion (Cd2+) sensing is carried out by cyclic voltammetry (CV) and chronoamperometry (CA) analysis under optimum conditions. The limit of detection (LOD) and limit of quantitation (LOQ) is found to be 1.27 nM and 4.24 nM respectively which is lower than some other reported works. The reproducibility and stability properties of the developed sensor are examined where the results are found to be satisfactory. The selective detection of Cd2+ ions in a river water sample is also evaluated with an excellent performance.

Sodium Salt of Partially Carboxymethylated Sodium Alginate-g-Poly(acrylonitrile): I. Photo-Induced Synthesis, Characterization, and Alkaline Hydrolysis.

An efficient redox initiating system, ceric ammonium nitrate/nitric acid, has been employed for the first time to carry out photo-induced graft copolymerization of acrylonitrile (AN) onto sodium salt of partially carboxymethylated sodium alginate, having an average degree of substitution value to be 1.10. The photo-grafting reaction conditions for maximum grafting have been systematically optimized by varying the reaction variables such as reaction time, temperature, the concentration of acrylonitrile monomer, ceric ammonium nitrate, and nitric acid, as well as the amount of the backbone. The optimum reaction conditions are obtained with a reaction time of 4 h, reaction temperature of 30 °C, acrylonitrile monomer concentration of 0.152 mol/L, initiator concentration of 5 × 10-3 mol/L, nitric acid concentration of 0.20 mol/L, amount of backbone of 0.20 (dry basis) and the total volume of the reaction system of 150 mL. The highest percentage of grafting (%G) and grafting efficiency (%GE) achieved are 316.53% and 99.31%, respectively. The optimally prepared graft copolymer, sodium salt of partially carboxymethylated sodium alginate-g-polyacrylonitrile (%G = 316.53), has been hydrolyzed in an alkaline medium (0.7N NaOH, 90-95 °C for ~2.5 h) to obtain the superabsorbent hydrogel, H-Na-PCMSA-g-PAN. The chemical structure, thermal characteristics, and morphology of the products have also been studied.

Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization: A Metal Free Methodology to Prepare Graft Copolymer

Reversible Addition Fragmentation Chain Transfer (RAFT) Polymerization: A Metal Free Methodology to Prepare Graft Copolymer

Effect of Different Comonomers Added to Graft Copolymers on the Properties of PLA/PPC/PLA-g-GMA Blends

The melt-free radical grafting of glycidyl methacrylate (GMA) onto poly (lactic acid) (PLA) with styrene (St), α-methylstyrene (AMS), and epoxy resin (EP) as comonomers in a twin-screw extruder was used to prepare PLA-g-GMA graft copolymers. The prepared graft copolymers were then used as compatibilizers to prepare PLA/PPC/PLA-g-GMA blends by melt blending with PLA and polypropylene carbonate (PPC), respectively. The effects of different comonomers in the PLA-g-GMA graft copolymers on the thermal, rheological, optical, and mechanical properties and microstructure of the blends were studied. It was found that the grafting degree of PLA-g-GMA graft copolymers was increased to varying degrees after the introduction of comonomers in the PLA-g-GMA grafting reaction system. When St was used as the comonomer, the grafting degree of the PLA-g-GMA graft copolymer increased most significantly, from 0.8 to 1.6 phr. St as a comonomer also most improved the compatibility between PLA and PPC, and the haze of the blends was reduced while maintaining high transmittance. In addition, the PLA-g-GMA graft copolymer with the introduction of St as a comonomer significantly improved the impact toughness of the blends, while the thermal stability and tensile strength of the blends remained largely unchanged.

All-Polycarbonate Graft Copolymers with Tunable Morphologies by Metal-Free Copolymerization of CO2 with Epoxides

Brush-type macromolecules (BMs) have attracted much attention over the past decades because of their unique properties and potential applications in nanoscience, drug-delivery systems, and photonics. A two-step strategy of synthesis of polycarbonate-grafted copolymers with either star-shaped or brush-typed morphologies using a “grafting from” approach is reported; the backbone in these all-polycarbonate graft copolymers is made of poly(cyclohexene carbonate) (PCHC), and the side grafts are made of poly(propylene carbonate) (PPC). In the first step, poly (vinyl-cyclohexene carbonate) (PVCHC) backbones of two different sizes (PVCHC35, PVCHC283) were prepared by copolymerization of vinyl-cyclohexene oxide (VCHO) with CO2 in the presence of triethylborane (TEB), using tetrabutyl ammonium succinate (TBAS) as the initiator. In the second step, the dangling vinyl double bonds of PVCHC were transformed into carboxylic acid groups. After partial neutralization of the latter using tetrabutyl ammonium hydroxide, the PPC grafts could be grown from the backbone carboxylic sites by copolymerization of propylene oxide (PO) with CO2 in the presence of TEB. Before attempting the synthesis of the above all-polycarbonate grafted copolymers, we check the viability of the above synthetic strategy by preparing graft copolymers made of a polymethacrylate backbone and PPC side grafts. In the latter case, the backbone was generated by reversible addition–fragmentation chain-transfer (RAFT) polymerization of methacrylic acid (MAA), followed by the growth of PPC side grafts using the backbone carboxylates as initiating sites. In both cases (PVCHC-g-PPC and PMAA-g-PPC), two types of architectures corresponding to two different morphologies were synthesized: star-shaped morphologies were obtained from rather short backbones, and relatively long grafts, on the one hand, and semiflexible cylinders were grown from rather long backbones and short grafts. These various structures were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography/light scattering (GPC/LS), and their morphologies were further investigated by atomic force microscopy (AFM). The reported synthetic method provides a robust way to synthesize well-defined polycarbonates with either star-type or brush-type morphologies and graft copolymers made of polyacrylate backbones and polycarbonate grafts. Thermal and mechanical properties of these graft copolymers were also investigated.

Impact of γ-rays on constructional, optical and thermal behavior of alkaline and non alkaline low density polyethylene

ABSTRACT In this study, we investigated the graft copolymerization of methyl methacrylate (MMA) onto low-density polyethylene (LDPE) in the presence of aniline as an inhibitor by gamma radiation. An alkaline treatment was carried out for the prepared graft copolymer. The structural properties of the prepared samples were examined via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD peaks were slightly shifted, indicating an interaction between MMA and the polyethylene matrix. The morphology of the samples confirmed the homogenous grafted phase scattered onto the LDPE surface. Analysis of the absorption spectra indicated an allowed indirect transition mechanism. The Urbach energy (EU) results showed that the value of the EU for grafted LDPE was found to be higher than that of pure LDPE—up to 15 kGy irradiation dose, although this value decreases upon grafting. However, the value of the EU for alkaline-treated grafted films decreases systematically by increasing the degree of grafting. The thermogravimetric analysis (TGA) of the sample indicated that the thermal stability of LDPE samples is significantly changed by grafting MMA onto it. Horowitz and Metzger's models were utilized to measure the activation energy of the thermal decomposition of all samples.

The graft copolymerization of N-vinyl-2-pyrrolidone onto carboxymethyl cellulose and its application for controlled release of water-soluble levofloxacin

The N-vinyl-2-pyrrolidone-grafted-carboxymethylcellulose was synthesised by employing a free radical polymerization method in an N2 atmosphere. It was found that 0.661 g concentration of monomer was sufficient to afford the maximum grafting parameters viz. % grafting (%G), % efficiency (%E) % Add on (%A) % and conversion (%C), but these grafting indicators showed a decreasing trend with increasing the concentration of monomer from 0.661 g to 0.993 g. The prepared graft copolymer was characterized by FT-IR, 1H NMR, TGA/DTG, SEM, GPC and X-ray diffraction (XRD) analysis. The hybrid of the grafted CMC with the sodium alginate was prepared and used to study the loading and release of levofloxacin drug, about 70% loading of levofloxacin was observed and its 80% release was observed in phosphate buffer solution (PBS) at pH 7.4 & 37 °C in 30 h.

In-situ syntheses of graft copolymers by metal-free strategies: combination of photoATRP and ROP

ABSTRACT A completely metal-free and environmentally friendly strategy is demonstrated for the preparation of graft copolymers by combining photoinduced Atom Transfer Radical Polymerization (ATRP) and Ring Opening Polymerization (ROP). Polymerizations are simultaneously realized in a one-pot manner. For this purpose, bare vinyl monomers, vinyl monomers with hydroxyl functional groups, and lactone monomers were simultaneously polymerized under visible light using specific catalysts. While vinyl monomers construct the main chain, the lactone monomers were polymerized from the hydroxyl functions present at the side chain. Spectral and chromatographic analyses prove that the utilized strategy is successful in the preparation of graft copolymers controlled molecular weights and narrow distributions.

Green Preparation of Hyphaene thebaica Fiber Grafted Acrylic Acid for Adsorption of Pb (II) ions from Aqueous Solution

In this study, a green chemistry approached was employed in the preparation of Hyphaene thebaica fiber grafted polyacrylic acid via microwave assisted method using potassium persulfate as chemical initiator. The optimum percentage grafting 92% was achieved under 5g concentration of acrylic acid, 0.2g concentration of potassium persulfate (KPS) and 2 minutes reaction time. The grafted sample was characterized using the following techniques, FTIR, SEM and XRD. The prepared graft copolymer was examined for adsorption of Pb (II) ions from aqueous solution in batch mode systems. The adsorption parameters such as pH, initial metal ion concentration and contact time were also studied. The Langmuir and Freundlich isotherm models were applied to simulate the equilibrium adsorption experimental data. The Langmuir model fitted well with experimental data with maximum adsorption capacity (qmax) of 20.37 mg/g at 45 minutes. Higher regression coefficient obtained confirmed the suitability of the Langmuir isotherm model which assumed monolayer coverage on the adsorbent surface. The adsorption studies revealed the efficacy of the grafted fiber for removal of Pb (II) ions from dilute aqueous solutions.

End-reactive poly(tetrahydrofuran) for functionalization and graft copolymer synthesis via a conjugate substitution reaction

α-(Chloromethyl)acryloyl cation, prepared from the corresponding acyl chloride and silver triflate, was used as an initiator for the living, cationic ring-opening polymerization of tetrahydrofuran. The α-end of the resulting poly(tetrahydrofuran) has an α-(chloromethyl)acrylate skeleton, which is an excellent substrate for nucleophilic conjugate substitution. In fact, treatment with a phenol resulted in a functionalized α-end. Moreover, 2-aminoethylanol and 2-mercaptoethanol afforded doubly functionalized polymers with two hydroxy groups at the α-ends via conjugate substitution and subsequent addition reactions. Since α-(chloromethyl)acrylate can be attacked by two equivalents of a nucleophile, it can function as a monomer in polycondensations with dithiols. Therefore, the α-(chloromethyl)acrylate chain end was subjected to polycondensation with 1,10-decandithiol in the presence of Bu3P, resulting in a graft copolymer. The above results suggest that the α-(chloromethyl)acryloyl cation is a functional initiator for incorporating a chain end reactive to a variety of nucleophiles for single and double end-functionalizations and the preparation of graft copolymers. Conjugate subst. allows single/double end-functionalization and graft copolymer synthesis.

Functionalization of cellulose as imprinted adsorbent for selective adsorption of matrine

ABSTRACTA novel molecular imprinted polymer (MIP) based on cellulose is fabricated for separation of matrine. Cellulose graft copolymer was first synthesized from cotton linter by atom transfer radical polymerization in ionic liquid with the acrylamide as monomer. Then, the prepared graft copolymer underwent sulfomethylation and subsequent crosslinking in the matrine solution. Effects of the parameters on the reaction degree were discussed, and the structural, component, and morphological characterization of the products were also conducted. The ability of the obtained cellulose‐based MIP (MIP‐SPAM) to adsorb matrine was evaluated by batch adsorption. Results showed that the sorption process was pH dependent, spontaneous, endothermic, and followed the Langmuir adsorption isotherm. Kinetics study revealed that pseudo‐second‐order was closed to the experimental data and both of the membrane diffusion and intraparticle diffusion controlled the matrine adsorption. Moreover, MIP‐SPAM possessed higher selective sorption property for matrine compared to the corresponding nonimprinted polymer. Finally, the MIP‐SPAM could be repeatedly used for five times without any significant loss in the initial binding affinity. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48392.

Synthesis a novel nano graft co-polymer and studying the swelling behaviors using different molar ratios of acrylic acid monomer

In this work, the nanoparticle graft co-polymer was prepared, by using glycerol as material containing the three alcoholic groups, and that reacted with terphthalic acid which have two carboxylic group as a first step, and then added 0.5 mole of fumaric acid to prepared graft co-polymer, as a second step by solubilization process. The acrylic acid monomer was added to the nano graft co-polymer in different number of moles (1.5, 2.0 & 2.5 mole). The swelling ratio measurements of the graft co-polymer, in three different buffer solution (2.2, 7.0 and 8.0), in the constant temperature at 310 K. The results showed that the increases of number of the moles of the acrylic acid monomer, Leads to increase of swelling ratio.

Banana fiber Cellulose Nano Crystals grafted with butyl acrylate for heavy metal lead (II) removal.

The present work deals with extraction of Cellulose Nano Crystals (CNCs) from Banana fiber using the steam explosion method. Extracted CNCs was grafted with butyl acrylate (BA) monomer with ceric ammonium nitrate (CAN) as an initiator. The prepared graft copolymer was analyzed using FTIR, XRD, SEM and EDAX. FTIR results indicate that the CH2 type of linkages was observed in the grafted copolymer showing effective formation of grafted copolymer. XRD results elucidate the changes in the crystalline behaviour of the prepared CNCs grafted butyl acrylate copolymer. SEM images of a prepared adsorbent was appeared to be heterogeneous and covered with clusters which will be suitable for adsorption. Batch adsorption studies was carried out for the removal of Pb(II) ions from the aqueous solution using the prepared copolymer. The parameters such as effect of pH, contact time, initial metal ion concentration and adsorbent dosage was investigated. From the observed results it was concluded that, the optimum pH: 5, contact time: 360 min, adsorbent dosage: 4 g/100 mL and initial metal ion concentration: 125 mg/L. The adsorption isotherm models of Pb(II) ions could be described very well by Freundlich model and the kinetic results revealed that pseudo-second-order kinetics showed a better fit.

Chitosan‑g‑maleic acid for effective removal of copper and nickel ions from their solutions

Pollution of the environment associated with discharging the toxic heavy metals in water makes us focus the light to solve this problem. In continuation of our efforts, we aim in this work to utilize the graft copolymer (chitosan‑g‑maleic acid) to purify water from copper and nickel ions. The graft copolymer has been synthesized using gamma radiation and the grafting conditions have been optimized by studying the influence of acetic acid concentration (0.5–10% V/V), monomer concentration (5–17.5% w/v), chitosan concentration (0.25–2.5% w/v) and absorbed dose (0.5–5 kGy). FT-IR and TGA have been employed to characterize the graft copolymer. The metal ions uptake by the prepared graft copolymer was investigated and the influence of contact time, solution pH, polymer concentration, and metal ion concentration was studied. Adsorption kinetic models (pseudo-first-order, pseudo-second-order, and intra-particle diffusion equations) and adsorption isotherms (Langmuir, Freundlich, and Temkin equations) were also studied. It was found that the adsorption kinetics and isotherm agreed well with pseudo-second-order and Langmuir equations, respectively, indicating that the adsorption was chemisorption. The adsorption capacities of CTS‑g‑MA were 312.4 mg g−1 and 70.1 mg g−1 for Cu2+ and Ni2+, respectively. Effect of co-existence of other cationic ions on the adsorption capacity was also investigated.

Amphiphilic graft copolymeric micelle using dextrin and poly (N-vinyl caprolactam) via RAFT polymerization: Development and application

Dextrin and poly (N-vinyl caprolactam) based amphiphilic graft copolymer has recently been developed using RAFT polymerization. The prepared graft copolymer has been characterized in details using FTIR and 1H NMR spectral analyses, GPC, TGA, FESEM, TEM and DLS analyses. GPC analysis results indicate that the polymerization is controlled, while the LCST value of the copolymer suggests that the synthesized copolymer demonstrates sol-gel behaviour on applying temperature. FESEM and TEM analyses envisage that the graft copolymer has spherical morphology with nanoscale dimension. DLS study reveals that the micellar size vary with change of pH and temperature, demonstrating the dual-responsive behaviour of the graft copolymer. Finally, the developed graft copolymer shows worthy efficacy towards the pH and thermo-responsive release of encapsulated pyrene in sustained manner.

Adsorptive removal of copper (II) and lead (II) using chitosan-g-maleic anhydride-g-methacrylic acid copolymer

In the present work, the maleic anhydride and methacrylic acid monomers were grafted one after another onto chitosan by using ceric ammonium nitrate as the initiator. The optimum conditions for grafting were studied by varying the initiator concentration, monomer concentration and reaction temperature. The synthesized grafted samples were subjected to various analytical techniques such as FTIR, XRD, TGA and DSC methods The proof of formation of graft copolymer was ascertained from the results of FTIR analysis and XRD studies. The TGA and DSC results conclude the highly thermally stable behavior of the prepared graft copolymer sample. The prepared graft copolymer was utilized for removing copper and lead from aqueous solutions and optimum adsorption parameters were evaluated under various pH, adsorbent dose, contact time and initial metal ion concentration. The adsorption and kinetic studies have been explained by Langmuir, Freundlich and pseudo − first order, second order and intra particle diffusion models. From the results, it was seen that Freundlich isotherm was best fit in the case of adsorption studies which followed pseudo second order kinetics. The obtained results showed that the chitosan-g-maleic anhydride-g-methacrylic acid copolymer was very efficient in removing the heavy metals copper and lead from aqueous solution.

Synthesis, characterization and antimicrobial activity of biguanidinylated chitosan-g-poly[(R)-3-hydroxybutyrate

Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water. The prepared graft copolymers were characterized by FTIR, 1H NMR, X-ray diffraction (XRD) and thermal analyses (TGA and DSC). TGA and DSC results revealed that the thermal stability and crystallinity of the graft copolymers were found to increase as the content of PHB increased. The antimicrobial activity of both ChG and ChG-grafted PHB, against Streptococcus pneumoniae, Bacillus subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi), were tested. Among them, ChG and ChG-grafted PHB with the highest grafting percent investigated showed to possess relatively higher antimicrobial activity with low MIC values in the range of 0.49–3.90μgmL−1.