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

The 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     

Melt grafting of maleic anhydride onto polypropylene with 1‐decene as a second monomer

The influence of 1‐decene as the second monomer on the melt‐grafting behavior of maleic anhydride (MAH) onto polypropylene (PP) was studied with differential scanning calorimetry and Fourier transform infrared spectroscopy. We found that the value of the grafting degree increased from 0.68% for pure MAH‐g‐PP to 1.43% for the system with a 1‐decene/MAH molar ratio of 0.3, whereas the maximum value with styrene (St) as the second monomer was 0.98% under an St/MAH molar ratio of 1.0. Compared with the contribution of St/MAH‐g‐PP to the peeling strength between the PP and polyamide (PA) layer for a PP/PA laminated film, the introduction of 1‐decene/MAH‐g‐PP increased the peeling strength from 180 g/15 mm to 250 g/15 mm. 1‐Decene inhibited the chain scission behavior of PP. 1‐Decene reacted with MAH to form a 1‐decene/MAH copolymer or the Alder‐ene reaction product before the two monomers grafted onto PP. The grafting of the reactive product onto PP greatly improved the grafting degree of MAH. What is more, because of the similar chemical structures of 1‐decene and PP, the affinity of 1‐decene with PP was higher than that of St. Compared with St, the introduction of less 1‐decene led to a higher grafting degree and higher peeling strength. Therefore, we concluded that 1‐decene was more effective for improving the grafting degree of MAH onto PP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Maleic anhydride/styrene melt grafting and crosslinking onto ethylene‐octene copolymer

Melt grafting of the multimonomer system of maleic anhydride (MAH)/styrene (St) onto ethylene‐octene copolymer (POE) was performed by a twin‐screw extruder. The effects of St and initiator contents as well as MAH/St on the grafting reaction were investigated. The structure and properties of the grafted POE were characterized by the Fourier transform infrared spectroscopy, melt flow index, dynamic rheological behaviors, and thermogravimetric analysis. It is shown that the addition of St can significantly enhance MAH grafting degree onto POE. MFI values of grafted POE are affected not only by MAH/St copolymer concentration, but also by initiator concentration. These data indicate that the interaction and reaction between MAH and St monomers plays an important role in the grafting reaction. St improves the grafting reactivity of MAH and reacts with MAH before the two monomers graft onto POE. And high grafting degree can be obtained while the gel content is still low. Compared with neat POE, grafted POE shows different dynamic rheological behaviors and high thermal stability. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Styrene‐butadiene‐styrene copolymer compatibilized interfacial modified multiwalled carbon nanotubes with mechanical and piezoresistive properties

In this study, styrene‐butadiene‐styrene tri‐block copolymer/multiwalled carbon nanotubes (SBS/MWNTs) were prepared by means of a solution blending method. To enhance the compatibility between SBS and MWNTs, the SBS grafted MWNTs (SBS‐g‐MWNTs) were used to replace MWNTs. The MWNTs were chemically hydroxylated by the dissolved KOH solution with ethanol as solvent and then reacted with 3‐Aminopropyltriethoxysilane (APTES) to functionalize them with amino groups (MWNT‐NH₂). The SBS‐g‐MWNTs were finally obtained by the reaction of MWNT‐NH₂ and maleic anhydride grafted SBS (MAH‐g‐SBS). The SBS‐g‐MWNTs were characterized by X‐ray photoelectron spectroscopy (XPS), Fourier transform‐infrared spectroscopy (FT‐IR), transmission electron microscopy (TEM), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The results showed that the SBS molecules were homogeneously bonded onto the surface of the MWNTs, leading to an improvement of the mechanical and electrical properties of SBS/SBS‐g‐MWNTs composites due to the excellent interfacial adhesion and dispersion of SBS‐g‐MWNTs in SBS. A series of continuous tests were carried out to explore the electrical‐mechanical properties of the SBS/SBS‐g‐MWNTs composites. We found out that, near the percolation threshold, the well‐dispersed SBS/SBS‐g‐MWNTs composites showed good piezoresistive characteristics and small mechanical destructions for the development of little deformation under vertical pressure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42945.     

Modification of acrylonitrile‐butadiene‐styrene terpolymer by graft copolymerization with maleic anhydride in the melt. II. Properties and phase behavior

The graft copolymerization of maleic anhydride (MAH) onto acrylonitrile‐butadiene‐styrene terpolymer (ABS) using dicumyl peroxide and benzoyl peroxide as the binary initiator and styrene as the comonomer in the molten state was described. The properties and phase morphologies of the modified products (ABS‐g‐MAH) were studied. The results indicate that the melt flow index (MFI) of ABS‐g‐MAH increases with the increase of MAH content, the initiator concentration, and the screw speed, whereas the MFI decreases with the increase of temperature. The impact strength and the percentage elongation of ABS‐g‐MAH both decreased and the tensile strength of ABS‐g‐MAH increased slightly as the grafting degree increased. The phase inversion behavior of the modified product was observed by transmission electron microscopy. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2834–2839, 2004     

Plasticization of nano‐CaCO3 in polystyrene/nano‐CaCO3 composites

The shear rheological properties of polystyrene (PS)/nano‐CaCO₃ composites were studied to determine the plasticization of nano‐CaCO₃ to PS. The composites were prepared by melt extrusion. A poly(styrene–butadiene–styrene) triblock copolymer (SBS), a poly(styrene–isoprene–styrene) triblock copolymer (SIS), SBS‐grafted maleic anhydride (SBS–MAH), and SIS‐grafted maleic anhydride were used as modifiers or compatibilizers. Because of the weak interaction between CaCO₃ and the PS matrix, the composites with 1 and 3 phr CaCO₃ loadings exhibited apparently higher melt shear rates under the same shear stress with respect to the matrix polymer. The storage moduli for the composites increased with low CaCO₃ concentrations. The results showed that CaCO₃ had some effects on the compatibility of PS/SBS (or SBS–MAH)/CaCO₃ composites, in which SBS could effectively retard the movement of PS chain segments. The improvement of compatibility, due to the chemical interaction between CaCO₃ and the grafted maleic anhydride, had obvious effects on the rheological behavior of the composites, the melt shear rate of the composites decreased greatly, and the results showed that nano‐CaCO₃ could plasticize the PS matrix to some extent. Rheological methods provided an indirect but useful characterization of the composite structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Mechanical and piezo‐resistive properties of styrene–butadiene–styrene copolymer covalently modified with graphene/styrene–butadiene–styrene composites

As novel piezoelectric materials, carbon‐reinforced polymer composites exhibit excellent piezoelectric properties and flexibility. In this study, we used a styrene–butadiene–styrene triblock copolymer covalently grafted with graphene (SBS‐g‐RGO) to prepare SBS‐g‐RGO/styrene–butadiene–styrene (SBS) composites to enhance the organic solubility of graphene sheets and its dispersion in composites. Once exfoliated from natural graphite, graphene oxide was chemically modified with 1,6‐hexanediamine to functionalize with amino groups (GO–NH₂), and this was followed by reduction with hydrazine [amine‐functionalized graphene oxide (RGO–NH₂)]. SBS‐g‐RGO was finally obtained by the reaction of RGO–NH₂ and maleic anhydride grafted SBS. After that, X‐ray diffraction, X‐ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, and other methods were applied to characterize SBS‐g‐RGO. The results indicate that the SBS molecules were grafted onto the graphene sheets by covalent bonds, and SBS‐g‐RGO was dispersed well. In addition, the mechanical and electrical conductivity properties of the SBS‐g‐RGO/SBS composites showed significant improvements because of the excellent interfacial interactions and homogeneous dispersion of SBS‐g‐RGO in SBS. Moreover, the composites exhibited remarkable piezo resistivity under vertical compression and great repeatability after 10 compression cycles; thus, the composites have the potential to be applied in sensor production. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46568.     

Peroxide‐catalyzed swell grafting of maleic anhydride onto polypropylene

A new grafting method was developed to incorporate maleic anhydride directly onto solid‐state polypropylene powders. Maleic anhydride grafts altered the nonpolar characteristics of polypropylene so that much better mixing was achieved in blends and composites of polypropylene with many other polymers and fillers. Maleic anhydride was grafted onto polypropylene by the peroxide‐catalyzed swell grafting method, with a maximum extent of grafting of 4.60%. Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, tensile testing, and impact testing were used to characterize the isotactic polypropylene (iPP), maleic anhydride grafted polypropylene (MAH‐g‐iPP), and (isotactic polypropylene)/(calcium carbonate) composites (iPP/CaCO₃). The crystallinity and heat of fusion of the MAH‐g‐iPP decreased as the extent of grafting increased. The mechanical properties of the CaCO₃ filled polypropylene were improved by adding MAH‐g‐iPP as a compatibilizing agent. The dispersion of the fillers in the polymer matrix and the adhesion between the CaCO₃ particles and the polymer matrix were improved by adding the compatibilizer.     

MAH溶液法接枝SBS的研究

采用马来酸酐（MAH）作为接枝单体,对苯乙烯—丁二烯—苯乙烯三嵌段共聚物（SBS）进行溶液接枝。研究了反应温度、反应时间、马来酸酐用量、引发剂种类及用量对接枝率的影响。得到最佳反应条件为：m（SBS）/m（MAH）/m（BPO）/m（溶剂）=100：10：0.8：400,反应温度75℃。反应时间3 h;红外光谱图证实了接枝物的生成。     

Styrene‐assisted grafting of maleic anhydride onto isotactic poly butene‐1

Grafting of maleic anhydride (MAH) onto isotactic poly butene‐1 (iPB‐1) was carried out by thermal decomposition of dicumyl peroxide (DCP) using electron‐donating monomer styrene (St), and were carried out in the molten state in a twin‐screw extruder according to an experimental design in which the content of MAH and St were varied. The calibration curve was constructed from FTIR measurements and titration which can obtain the absolute amounts of grafted MAH according to FTIR data. The proposed mechanism was that when St is added to the iPB‐1/MAH/peroxide grafting system, St reacted first with MAH to form a charge‐transfer complex (CTC). Then CTC react (or copolymerize) with macroradicals. The grafting of MAH onto iPB‐1 (iPB‐1‐MAH) accelerated crystalline transformation rate of form II to I. The contact angle decreased with the increase of grafting degree, which indicated that surface polarity increased. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Compatibility effect of radiation‐grafting‐functionalized styrene–butadiene–styrene on polyamide 6/styrene–butadiene–styrene blends

Styrene–butadiene–styrene (SBS) was grafted with dibutyl maleate (DBM), methacrylic acid (MAA), or maleic anhydride (MAH) by ⁶⁰Co γ‐rays. The grafted SBS was blended with polyamide 6 (PA6). The compatibility of the PA6/SBS blends was studied with scanning electron microscopy and rheological measurements. The results showed significant improvement in the compatibility of PA6 blended with MAH‐ or MAA‐grafted SBS, with the former being more effective, whereas grafting DBM was ineffective in this respect. Mechanisms of the compatibility enhancement and ineffectiveness are discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Blends of poly(ethylene terephthalate) bottle waste with modified styrene butadiene rubber through reactive mixing

Styrene butadiene rubber (SBR) was modified by the grafting reaction of maleic anhydride (MAH) in the presence of the initiator benzoyl peroxide (BPO). This modified elastomer was then blended with poly(ethylene terephthalate) (PET) bottle waste, and the mechanical and morphological properties of the resulting blends were studied. The amount of grafted MAH was determined by chemical titration. The results revealed that the concentrations of MAH and BPO strongly affected the grafting process. The morphology of the dispersed phase for blends of PET waste and SBR‐g‐MAH was quite different from that of a simple blend of PET waste and SBR. Dynamic mechanical thermal analysis revealed suitable compatibility between PET waste and styrene butadiene rubber‐graft‐maleic anhydride (SBR‐g‐MAH). The enhanced compatibility resulted in better impact properties. The better compatibility was concluded to result from bond formation between the carbonyl group of SBR‐g‐MAH and the hydroxyl or carboxyl end groups of PET. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1615–1623, 2006     

Compatibilizer in waste tire powder and low‐density polyethylene blends and the blends modified asphalt

With the increasing ratio of waste tire powder (WTP) to low‐density polyethylene (LDPE), the hardness and tensile strength of the WTP/LDPE blends decreased while the elongation at break increased. Five kinds of compatibilizers, such as maleic anhydride‐grafted polyethylene (PE‐g‐MA), maleic anhydride‐grafted ethylene‐octene copolymer (POE‐g‐MA), maleic anhydride‐grafted linear LDPE, maleic anhydride‐grafted ethylene vinyl‐acetate copolymer, and maleic anhydride‐grafted styrene‐ethylene‐butylene‐styrene, were incorporated to prepare WTP/LDPE blends, respectively. PE‐g‐MA and POE‐g‐MA reinforced the tensile stress and toughness of the blends. The toughness value of POE‐g‐MA incorporating blends was the highest, reached to 2032.3 MJ/m³, while that of the control was only 1402.9 MJ/m³. Therefore, POE‐g‐MA was selected as asphalt modifier. The toughness value reached to the highest level when the content of POE‐g‐MA was about 8%. Besides that the softening point of the modified asphalt would be higher than 60°C, whereas the content of WTP/LDPE blend was more than 5%, and the blends were mixed by stirring under the shearing speed of 3000 rpm for 20 min. Especially, when the blend content was 8.5%, the softening point arrived at 82°C, contributing to asphalt strength and elastic properties in a wide range of temperature. In addition, the swelling property of POE‐g‐MA/WTP/LDPE blend was better than that of the other compalibitizers, which indicated that POE‐g‐MA /WTP/LDPE blend was much compatible with asphalt. Also, the excellent compatibility would result in the good mechanical and processing properties of the modified asphalt. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Ultrasound initiated maleic anhydride grafted onto a novel polypropylene copolymer

The reaction of maleic anhydride (MAH) grafted onto propylene‐based copolymer (DP) without adding any initiator was conducted through ultrasound assisted extrusion in this article. The effects of ultrasound power, die temperature, and MAH content on the grafting degree and efficiency were studied. With increasing ultrasound power, the grafting degree and efficiency of DP‐g‐MAH increase. The presence of ultrasound with higher power and lower die temperature is beneficial to increase the grafting degree and efficiency. The increase of MAH content can increase the grafting degree but reduce the grafting efficiency. Based on the results of melt flow index, dynamical rheological, gel permeation chromatograph (GPC), and Fourier transform infrared spectroscopy (FTIR) tests, the mechanisms of the grafting reaction were proposed. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Properties of poly(ethylene 1‐octene)‐g‐maleic anhydride copolymers prepared via solvothermal process

The poly(ethylene 1‐octene)‐g‐maleic anhydride copolymers (POE‐g‐MAH) with high grafting degree (GD) (>9%) have previously been obtained by a solvothermal method in our laboratory. It is found that the low GD (less than 2.5%) did not change the bulk properties of polyolefine elastomers (POE). Thereforefore, it is worth further understanding whether a high GD POE‐g‐MAH copolymer differs from the pure POE in its comprehensive properties and performance. In this article, POE‐g‐MAH with different GDs were synthesized and characterized by thermogravimetric analyze (TGA), differential scanning calorimetry (DSC), wide angle X‐ray diffraction spectroscopy (WAXD), and dynamic rheological testing. The results show that the thermal decomposition temperature, melting points, the crystallization temperatures, and the crystallinities were decreased by the increasing GD. By WAXD, three peaks respectively, attributed to the amorphous phase, the (110) and (200) interferences of the orthorhombic unit cell were detected, and they also decreased by the increasing GD. And the POE‐g‐MAH copolymers had higher storage modulus (G′), loss modulus (G″), and complex viscosity (η*) than those of pure POE. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

接枝改性SBS对PS/SBS/CaCO_3复合材料形态和力学性能的影响

采用马来酸酐(MAH)和苯乙烯(St)作为接枝单体,通过溶液聚合法合成接枝极性基团的苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS),然后与聚苯乙烯(PS)基体、碳酸钙(CaCO_3)粒子复合,用傅立叶红外光谱仪表征接枝处理前后SBS表面化学结构的变化;并研究了SBS改性对复合材料微观结构和力学性能的影响.结果表明:双单体溶液聚合法成功地将极性基团接枝在SBS链上;填充SBS-g-MAH后,促进CaCO_3在PS基体中的分散、改善PS-CaCO_3粒子间界面粘接,起到良好的增容作用;SBS-g-MAH和CaCO_3粒子对PS基体具有协同增强增韧作用,同时能提高复合材料的拉伸强度和冲击强度.     

Effects of ABS‐g‐MAH on mechanical properties and compatibility of ABS/PC alloy

The effects of a compatibilizer, namely, an acrylonitrile–butadiene–styrene copolymer (ABS) grafted with maleic anhydrade (MAH) (ABS‐g‐MAH), on the mechanical properties and morphology of an ABS/polycarbonate (PC) alloy were studied The results showed that a small quantity of ABS‐g‐MAH has a very good influence on the notched Izod impact strength of the ABS/PC alloy without compromising other properties such as the tensile strength, flexural strength, and Vicat softening temperature (VST). The impact strength of the ABS/PC alloy, to a great extent, depends on the loading of ABS‐g‐MAH and the degree of grafting (DG) of MAH in the ABS‐g‐MAH. DSC analysis and SEM observation confirmed that ABS‐g‐MAH could significantly improve the compatibility of the ABS/PC alloy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 831–836, 2001     

Synthesis and characterization of high‐density polypropylene‐grafted polyethylene via a macromolecular reaction and its rheological behavior

High‐density polyethylene grafted isotactic polypropylene (PP‐g‐HDPE) was prepared by the imidization reaction between maleic anhydride grafted polyethylene and amine‐grafted polypropylene in a xylene solution. The branch density was adjusted by changes in the molar ratio between maleic anhydride and primary amine groups. Dynamic rheology tests were conducted to compare the rheological properties of linear polyolefins and long‐chain‐branched polyolefins. The effects of the density of long‐chain branches on the rheological properties were also investigated. It was found that long‐chain‐branched hybrid polyolefins had a higher storage modulus at a low frequency, a higher zero shear viscosity, a reduced phase angle, enhanced shear sensitivities, and a longer relaxation time. As the branch density was increased, the characteristics of the long‐chain‐branched structure became profounder. The flow activation energy of PP‐g‐HDPE was lower than that of neat maleic anhydride grafted polypropylene (PP‐g‐MAH) because of the lower flow activation energy of maleic anhydride grafted high‐density polyethylene (HDPE‐g‐MAH). However, the flow activation energy of PP‐g‐HDPE was higher than that of PP‐g‐MAH/HDPE‐g‐MAH blends because of the presence of long‐chain branches. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of maleic anhydride grafted polybutadiene on the compatibility of polyamide 66/acrylonitrile‐butadiene‐styrene copolymer blend

The addition of maleic anhydride grafted polybutadiene (PB‐g‐MAH) can greatly improve the compatibility of polyamide 66 (PA66)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blends. Unlike the commonly used compatibilizers in polyamide/ABS blends, PB‐g‐MAH is compatible with the ABS particles' core phase polybutadiene (PB), rather than the shell styrene‐acrylonitrile (SAN). The compatibility and interaction of the components in the blends were characterized by Fourier transform‐infrared spectra (FTIR), Molau tests, melt flow index (MFI), dynamic mechanical analyses (DMA), and scanning electron microscopic (SEM) observations. The results show that PB‐g‐MAH can react with the amino end groups in PA66 while entangle with the PB phase in ABS. In this way, the compatibilizer anchors at the interface of PA66/ABS blend. The morphology study of the fracture sections before and after tensile test reveals that the ABS particles were dispersed uniformly in the PA66 matrix and the interfacial adhesion between PA66 and ABS was increased significantly. The mechanical properties of the blends thus were enhanced with the improving of the compatibility. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Modification of low‐density polyethylene by graft copolymerization with maleic anhydride and blends with polyamide 6

Modification of low‐density polyethylene (LDPE) hyperbranched grafting with a maleic anhydride (MAH) was carried out using corotating twin screw extruder in the presence of benzoyl peroxide. The LDPE/polyamide 6 (PA6) and LDPE‐g‐MAH/PA6 blends were obtained with a corotating twin screw extruder. The melt viscosity of the grafted LDPE was measured by a capillary rheometer. The grafted copolymer was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy The effects of variations in temperature, PA6 loading, and benzoyl peroxide and MAH concentration were investigated. The results show that most MAH monomers were grafted onto the LDPE at a lower MAH concentration. With the proper selection of the reaction parameters, we obtained a grafting degree higher than 4.9%. Mechanical test results indicate that the blends had good interfacial adhesion and good stability of the phase structure during heating, which was reflected in the mechanical properties. Furthermore, the results reveal that the tensile strength of the blends increased continuously with increasing PA6 content. Moreover, the home‐synthesized maleated LDPE could be used for the compatibilization of LDPE/PA 6 blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010