Amount Of Maleic Anhydride Research Articles

Физико-механические свойства многокомпонентных нанокомпозитов на основе полиолефинов

The results of a study of the effect of the various types of fillers concentration at the nanoscale level, zinc stearate, aluminum, technical carbon — on the physical and mechanical properties of nanocomposites based on polyolefins are presented. High density polyethylene, low density polyethylene and polypropylene were used as polyolefins. In order to improve the compatibility of polyolefins with fillers, a copolymer of high density polyethylene with maleic anhydride was used as a compatibilizer. The amount of maleic anhydride in the high density polyethylene was 5.7 wt %. Investigated such properties of nanocomposites as ultimate tensile stress, tensile yield strength, elongation at break, static bending strength and Vicat heat resistance. It was found that the use of a compatibilizer contributes to a significant improvement in the main physico-mechanical characteristics of nanocomposites, which indicates the technological compatibility of the mixed components of the mixture with the polymer matrix. It was found that in the presence of fillers, the elongation at break of the nanocomposites slightly decreases. It is shown that an increase in the content of technical carbon in the polymer matrix in the presence of 5.0 wt % concentration of aluminum is accompanied by an increase in the ultimate tensile stress and yield stress during stretching of nanocomposites with a maximum at a certain ratio of the mixture components. It was found that in polyolefins characterized by a relatively high degree of crystallinity, the maximum value of the ultimate tensile stress is achieved at a lower concentration of technical carbon.

Synthesis and characterization of compatibilizers for blends of polypropylene carbonate and polybutylene succinate via free‐radical grafting of maleic anhydride

ABSTRACTThis study focuses on creating an optimal grafting compatibilizer for blends of polypropylene carbonate (PPC) and polybutylene succinate (PBS). PPC and PBS were blended separately with different amounts of maleic anhydride (MAH) and with and without dicumyl peroxide (DCP) to aid the free‐radical grafting. Titration analysis evidenced that MAH reacted with the polymers terminal groups and backbones using free‐radical functionalization. Thermogravimetric analysis (TGA) and gas permeation chromatography (GPC) results demonstrated how the thermal stability of PPC improves with the addition of MAH. Proton NMR proved that, in both PPC and PBS formulations, ring‐opening reactions and grafting of the intact MAH ring occur, as well as interchain grafting producing network structures. The rheological analysis showed that small quantities of MAH and DCP increase the viscosity of the resins. The compatibilizer that was determined to be most reactive and stable of all the formulations analyzed was PPC with 2% MAH and DCP and its effect in the morphology of PPC‐PBS blends was proven successful by a reduction of the PPC droplet size. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47553.

Isosorbide as Core Component for Tailoring Biobased Unsaturated Polyester Thermosets for a Wide Structure-Property Window.

Biobased unsaturated polyester thermosets as potential replacements for petroleum-based thermosets were designed. The target of incorporating rigid units, to yield thermosets with high thermal and mechanical performance, both in the biobased unsaturated polyester (UP) and reactive diluent (RD) while retaining miscibility was successfully achieved. The biobased unsaturated polyester thermosets were prepared by varying the content of isosorbide, 1,4-butanediol, maleic anhydride, and succinic anhydride in combination with the reactive diluent isosorbide-methacrylate (IM). Isosorbide was chosen as the main component in both the UP and the RD to enhance the rigidity of the formed thermosets, to overcome solubility issues commonly associated with biobased UPs and RDs and volatility and toxicity associated with styrene as RD. All UPs had good solubility in the RD and the viscosity of the mixtures was primarily tuned by the feed ratio of isosorbide but also by the amount of maleic anhydride. The flexural modulus and storage modulus were tailorable by altering the monomer composition The fabricated thermosets had superior thermal and mechanical properties compared to most biobased UP thermosets with thermal stability up to about 250 °C and a storage modulus at 25 °C varying between 0.5 and 3.0 GPa. These values are close to commercial petroleum-based UP thermosets. The designed tailorable biobased thermosets are, thus, promising candidates to replace their petroleum analogs.

Understanding the Miscibility and Morphology of Poly(methyl methacrylate) and Styrenic Copolymer Blends of Tunable Domain Sizes

In the present study, we have investigated the miscibility, morphology and mechanical behavior of poly(methyl methacrylate) (PMMA) blends with a series of poly(styrene-co-maleic anhydride) (SMA) copolymers containing varying amounts of maleic anhydride (MA) content (from 8 to 26%). The experimental findings have been substantiated by the modeling studies to gain fundamental understanding of the observed phenomena with respect to the miscibility of the PMMA and SMA blends of a given MA content. The morphological differences, molecular weights, domain sizes and mechanical behavior of the blends at a given ratio of PMMA and copolymers have been investigated and a correlation has been made between the morphological understanding to the molecular weights and mechanical properties. The results indicate that the PMMA/SMA blends are miscible only at a certain MA content providing transparent PMMA/SMA blends without affecting any of the enabling properties of PMMA that are of commercial interest through a facile melt mixing process. The surface hardness and % recovery (nano-indentation) of these blends were evaluated as well to gain fundamental understanding of the surface characteristics and mechanicals of the blends.

Natural Rubber Based Compatibilizer Prepared in Twin Screw Extruder: Optimization Percentage of Grafted Maleic Anhydride Using Experimental Design

Maleic anhydride grafted natural rubber compatibilizer was prepared in molten state using twin screw extruder. Amount of maleic anhydride and initiator, as well as screw rotation were varied according to Box-Behnken experimental design. Titration of acid group from the anhydride function and FTIR spectra analysis were carried out as quantitative and qualitative analysis of grafted MA, respectively. The results showed that the percentages of grafted MA for all samples were ranged from 1.31 to 5.36%. The optimum conditions are predicted at 14.4 phr of MA level, 0.41 phr of BPO level, and 71 rpm screw rotation giving 5.39 ± 0.16% of grafted MA. FTIR spectra showed that the MA and carbonyl functional group were found in the compatibilizer suggested the presence of grafted MA and ring opening reaction.

Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR FT-IR) Mapping Coupled with Multivariate Curve Resolution (MCR) for Studying the Miscibility of Chlorobutyl Rubber/Polyamide-12 Blends.

A series of chlorobutyl rubber/polyamide-12 (CIIR/PA-12) blends compatibilized by different amounts of maleic anhydride (MAH) grafted polypropylene (PP-g-MAH) were investigated by attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) mapping. Multivariate curve resolution (MCR) was used to process the FT-IR images. Both the spectra of pure components in the blends and their concentration distributions in a micro-region were acquired. Our results demonstrated that the blend with 15 parts per hundred rubber PP-g-MAH showed the best miscibility. An amide interphase and an imide interphase were inferred by analyzing the spectra of MCR component 3 of the blends with and without PP-g-MAH, respectively. Correspondingly, two different compatibilizing mechanisms were proposed for these blends.

Wavelength Sensitivity in Polypropylene/Clay Composite Photo-Oxidation

The photo-oxidation behaviour of polypropylene/maleic anhydride-grafted polypropylene/organic modified montmorillonite (PP/PPgMA/OMMT) composites with short wavelength (UVC) and long wavelength (UVA) ultraviolet radiation was examined. The samples were prepared in a co-rotating twin-screw extruder and compatibilizers with different degrees of maleation were used. The photo-oxidative stability was studied using FTIR spectroscopy and microscopy. During UVA exposure, the rate of photo-oxidation of PP/PPgMA/OMMT increased with the amount of maleic anhydride from 0.1 to 0.5 wt.% in PPgMA. However, even after 2500 h of exposure to the radiation, the FTIR spectrum of pristine PP did not show significant changes. For UVC radiation, the rate of photo-oxidation of PP/PPgMA/OMMT composites was the same as that of pristine PP. On the other hand, there was a difference between PP and PP/PPgMA/OMMT composites in the formation of a crack on the back surfaces of the sheets facing the UVC sources. The difference was due to the presence of Fe3+ in clay layers that had the effect of UV-protection and blocking in the UVC region.

Properties of the Treated Kenaf/Polypropylene (PP) Composites

Untreated and treated kenaf fibers were used in the fabrication of kenaf/polypropylene (PP) composites. The ratio of the fibers as fillers and PP as matrix was 40:60 in wt%. Small amounts of maleic anhydride grafted polypropylene (MAPP) were added as a coupling agent. Fourier transform infrared (FTIR) spectroscopy was used to estimate the cellulose contained in the treated kenaf fibers. A flexural test of the composites was conducted by referring to JIS (A 5905, 1994, Fiberboards). A composite with alkali-treated fiber had better properties (modulus of rupture (MOR) and elasticity (MOE), absorbed water and thickness in swelling) than that with a combination of steam-alkali and alkali-bleaching treated fibers, and untreated fibers. The dispersion characteristic of the fibers within the polymer matrix has been suggested as one of the significant factors affecting the composite properties. These composites are classified as medium density fiberboard (MDF, JIS, type 30 and 25).

Influence of residual lignin content on physical and mechanical properties of kraft pulp/pp composites

The effect of residual lignin content on the mechanical strength and water absorption of kraft pulp/ polypropylene composites was studied. To meet this objective, hornbeam wood chips were converted to kraft pulp at three different alkalinities (15, 20, and 25%) and three different cooking times (60, 90, and 120 min). The residual lignin contents of these pulps were determined according to the TAPPI standard. Kraft pulp was mixed with polypropylene (PP) at 50% weight ratios. The amount of maleic anhydride (MAPP) coupling agent was fixed at 4 per hundred compounds (phc) for all formulations. The results indicated that the lignin residual content decreased with increasing cooking time and alkalinity in kraft pulp. Also, it was found that tensile strength, tensile modulus, flexural strength, and flexural modulus were increased by increasing the alkalinity and cooking time; however, the notched impact strength and water absorption decreased. Overall, decreasing the lignin content had a positive impact on the flexural and tensile properties and had a negative effect on the notched impact strength.

Synthesis of wheat straw composite superabsorbent

ABSTRACTA novel wheat straw composite superabsorbent was prepared by graft polymerization with acrylic acid (AA), acrylamide (AM), and maleic anhydride‐modified wheat straw in aqueous solution, using N,N‐methylene‐bis‐acrylamide (MBA) as a cross‐linker and ammonium persulfate (APS) and sodium bisulfite (SBS) as redox initiators. Factors influencing the degree of carboxylation, such as reaction time, reaction temperature, and the amount of maleic anhydride, were investigated. Morphologies and structure of the wheat straw composite superabsorbent were characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and X‐ray diffraction (XRD). Water absorption of wheat straw composite superabsorbent was rapid, requiring 13.1 min to reach 63% of equilibrium absorbency (781 g/g). FTIR spectra indicate that maleic anhydride has been reacted onto the wheat straw backbone and the structure of wheat straw graft copolymer is formed. SEM data show that the fibrous morphology of wheat straw disappears and gel aggregates with many large microporous holes are formed after wheat straw graft modification. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3404–3410, 2013

Thermoplasticization of High Amylose Starch by Chemical Modification Using Reactive Extrusion

Modified thermoplastic high amylose starch (MTPS) was synthesized by reactive extrusion in the presence of maleic anhydride (MA) as an esterification agent in a twin-screw extruder. The objective of this work was the preparation of reactive thermoplastic starch in the presence of glycerol and with different amounts of maleic anhydride (MA) and free-radical initiator, in order to improve processability and reactivity. The concentration of MA added varied from 2 to 6 wt% (of starch + glycerol), and the free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, also called Luperox 101, varied from 0.1 to 0.5 wt% (of starch + glycerol). Characterization of maleated thermoplastic starch was performed using dynamic light scattering and thermal analysis. Further, proof of chemically modified extrudate was determined by Fourier transform infrared spectroscopy and by soxhlet extraction with acetone. The modified high amylose corn starch (20 or 30% glycerol) could be pelletized and gave pellets that were more transparent than thermoplastic starches not modified with maleic anhydride. There was negligible change in hydrodynamic radius as the percentage of maleic anhydride increased. However, as the percentage of Luperox 101 increased, the hydrodynamic radius decreased. It could be inferred that the molecular weight decreased as the percentage of free-radical initiator increased. Using the maximum temperature in the extrusion process of 165 °C instead of 135 °C caused a decrease in the hydrodynamic radius, due to the high influence of the temperature profile on the molecular weight of the thermoplastic starch. The MTPS samples presented higher melting temperatures compared to TPS samples. The soxhlet studies indicated that the plasticizer, glycerol, was chemically linked to the starch. Using the maximum temperature of 165 °C versus 135 °C in the extrusion temperature profile resulted in more interaction between glycerol and starch.

Viscoelasticity of Asphalts Modified with SEBS Copolymers Functionalized with Various Amounts of Maleic Anhydride

Abstract It is known that the microstructure of polymer-modified asphalts (PMA) depends strongly of the characteristics of the polymer. The modifier polymer improves the mechanical properties of pure asphalt when used in paved roads. In this work, asphalt is modified using reactive polymers obtained via functionalization of styrene-ethylene/butylene-styrene (SEBS) copolymers in solution using various amounts of benzoil peroxide (BPO) as initiator and maleic anhydride (MAH). The resulting functionalized copolymer (SEBS-g-MAH) with variable amounts of grafting (variable reactivity) is blended with the asphalt at small contents (2–4 wt. %). The amount of MAH grafting was determined by FTIR, 1HNMR, GPC, DSC and by titration with KOH, and this amount is readily correlated with the improvement of the mechanical properties and thermal stability of the asphalt. In addition, the limit of the polymer-asphalt compatibility is determined for these systems.

Intercalated polypropylene/clay nanocomposite and its physical characteristics

Polypropylene (PP)/organo-clay nanocomposites were prepared via a melt-mixing method through two-step melt compounding in a co-rotating intermeshing twin-screw extruder. Different amounts of maleic anhydride (MA)-grafted PP (PP-g-MA) were adopted during compounding as a compatibilizer, and then not only the influence of MA contents of PP-g-MA compatibilizer on the clay dispersion but also thermal and rheological properties of nanocomposites were investigated. The use of PP-g-MA led to not only good dispersion of the clay but also its heterogeneous intercalation. Dispersibility of silicate layers of the clays in the hybrids was investigated by using X-ray diffraction (XRD), and thermal stability was examined by thermal gravimetric analysis (TGA). Characteristic rheological behaviors of the PP/clay nanocomposites with various PP-g-MA (MA 0.2, 0.5, and 1.0 wt%) were also tested.

Synthesis and characterization of poly(methyl methacrylate‐co‐maleic anhydride) copolymers and its potential as a compatibilizer for amorphous polyamide blends

AbstractPoly(methyl methacrylate‐co‐maleic anhydride) copolymers (MMA‐MA) have been synthesized by solution method, using toluene as solvent and benzoyl peroxide as initiator. The MMA‐MA copolymers were characterized by size exclusion chromatography, Fourier transforms infrared spectroscopy (FTIR), and titration. It was found that the modified polymerization procedure used in this work was more effective in controlling the molecular weight when adding different amounts of maleic anhydride (MA) than procedures previously used. In spite of the significant difference in reactivity ratios between MMA and MA, up to 50% of the MA added to the reactor was incorporated into the copolymer. The evidences for reactions of the MA groups of the MMA‐MA copolymer with the amine end groups of the amorphous polyamide (aPA) during melt blending was obtained by rheological measurements. In this work, the molecular weight and the content of MA reactive functional groups in the MMA‐MA copolymer were varied independently and its effects on the interaction with aPA were studied. It was observed that a compromise between molecular weight and the level of reactive functional group of the compatibilizer should be sought to improve the compatibilization of the polymer systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

Study of the Impact Resistance of Physically and Dynamically Vulcanized Mixtures of PP/EPDM

AbstractPhysically and dynamically vulcanized (TPV) mixtures of polypropylene (PP) and ethylene propylene diene terpolymer (EPDM) are prepared by extrusion in order to improve the impact resistance of PP. To enhance the chemical compatibility and provide better interaction between the PP and EPDM in the physical mixtures, both polymers are modified with maleic anhydride (MAH) in solution using xylene as solvent and dicumyl peroxide (DCP) as initiator. The qualitative and quantitative determination of the degree of grafting is study by Fourier Transform Infrared Spectroscopy (FTIR) and varying the amount of DCP and/or amount of MAH in order to determine the optimum amounts to obtain the highest degree of grafting. The effect of the relation of PP/EPDM, the amount of reinforcement filler and mix rate are studied for modified polymer mixtures (PP‐g‐MAH/EPDM‐g‐MAH). For the TPV of PP/EPDM the effects of amount and triallylisocyanurate (TAC) as coupling agent in presence of different amounts of DCP are studied. The physical mixtures of modified polymers prepared with a PP/EPDM ratio of 80/20 and the TPVs blends prepared with a PP/EPDM ratio of 70/30 and containing 15% filler at 60 rpm show the highest impact resistance. The impact resistance, melt flow index and hardness of the different mixtures are measured to determine their possible applications to prepare front panels and bumpers for automobiles by injection molding.

Grafting copolymerization of maleic anhydride onto styrene‐butadiene‐styrene block copolymer through solvothermal process

AbstractThe grafting copolymerization of maleic anhydride (MAH) onto styrene‐butadiene‐styrene terpolymer (SBS) was carried out through a new synthesis method––solvothermal synthesis. Infrared (IR) spectra and solid state 13C‐NMR confirmed that maleic anhydride was successfully grafted onto the SBS backbone. The effects of different solvents, different initiators and their concentration, the amount of MAH, SBS concentration, and reaction time on the graft degree were evaluated, and the optimal conditions were obtained. Results indicated that the grafting reaction of MAH onto SBS through solvothermal method can be carried out in both good solvents and poor solvents, which are much different from the traditional solution grafting method, and high grafting degree can be obtained in good solvents. Finally, we also compared the grafting degree (GD) prepared by the solvothermal method with that by the melt grafting method and solution grafting method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5274–5279, 2006

Polyesters from renewable resources: Preparation and characterization

AbstractPolyesters were synthesized with monoglycerides prepared from rubber seed oil, a renewable resource. Monoglycerides were obtained by an alcoholysis method from the oil, which was neat or modified by treatments with different amounts of maleic anhydride at 230°C. The polyester resins were subsequently prepared by the condensation polymerization of the monoglycerides with phthalic anhydride. The monoglycerides and resins were characterized by spectroscopic analysis and measurements of the physicochemical properties. The chemical resistance of the polyesters was also studied. The results revealed that the polyesters prepared from the modified monoglycerides possessed better properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3748–3755, 2006

Rubber seed oil modified with maleic anhydride and fumaric acid and their alkyd resins as binders in water‐reducible coatings

AbstractRubber seed oil (RSO) was modified with different amounts of maleic anhydride, and RSO alkyds (50% oil length) were modified to various extents by the incorporation of different amounts of maleic anhydride and fumaric acid. All the resins were evaluated as water‐reducible binders. Modification with maleic anhydride increased the acid and saponification values of RSO but reduced the iodine value. RSO modified with maleic anhydride exhibited lower amounts of volatile organic compounds (<20 g/L) than the corresponding RSO alkyds (34–87 g/L). The alkyd samples were superior to the modified RSO in chemical resistance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3256–3259, 2003

Quiescent crystallization kinetics and morphology of isotactic polypropylene resins for injection molding. I. Isothermal crystallization

The quiescent isothermal crystallization kinetics of polypropylene was studied as a function of molecular weight (Mw), amount of ethene, and amount of maleic anhydride and acrylic acid grafting. Differential scanning calorimetry and polarized light optical microscopy were used to follow this kinetics. It was observed that the linear growth rate, G, decreased with the increase of Mw, but increased with the amount of ethene. In the grafted polymers, as the amount of grafting increased, G decreased. The fold surface free energy, σe, was found to increase with the increase in Mw. The heterophasic and grafted polymers had σe values higher than the homopolymers. All samples showed spherulitic morphology, except the acrylic acid-grafted polypropylene that showed axialitic morphology. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1159–1176, 1998

The role of matrix molecular weight in rubber toughened nylon 6 blends: 1. Morphology

The effects of polyamide molecular weight on morphology generation in nylon 6 blends with maleated elastomers are described. The elastomers used include styrene—butadiene—styrene block copolymers with a hydrogenated mid-block, SEBS, and versions with X % grafted maleic anhydride, SEBS-g-MA- X%, and an ethylene/propylene copolymer, EPR, and a maleated version EPR-g-MA. The molecular weight of the nylon 6 phase governs the melt viscosity of the blend matrix and the number of amine end groups available for reaction with the maleic anhydride groups in the rubber phase; both of which influence the size, shape, and size distribution of the rubber phase formed during blending. In general, rubber particle size, distribution, and the amount of occluded material in the rubber phase decreases as the nylon 6 molecular weight increases. Measurement of the extent of reaction between the amine end groups and the grafted maleic anhydride revealed that a higher fraction of nylon 6 chains are grafted to the rubber matrix as the nylon 6 molecular weight increases. The weight average rubber particle size and size distribution for blends based on SEBS-g-MA- X% are smaller than corresponding blends based on SEBS/SEBS-g-MA-2% mixtures containing the same amount of maleic anhydride. EPR/EPR-g-MA mixtures produce non-spherical morphologies that are typically larger and more polydisperse than SEBS type elastomers. One reason for this difference is the fact that SEBS elastomers react more readily with nylon 6 than do EPR/EPR-g-MA mixtures as determined by extent of amine reaction and torque rheometry. The weight average rubber particle size for blends of the various rubbers and nylon 6 materials were correlated using a modified Taylor theory analysis. A master curve was generated by determining shift factors needed to superimpose the maleated rubber/nylon 6 curves onto a reference curve for the non-maleated rubber, SEBS. The overall shift factors correlate linearly with the maleic anhydride content of the rubber phase.