Surface modification of magnesium aluminum hydroxide nanoparticles with poly(methyl methacrylate) via one-pot in situ polymerization
Graphical abstract
Highlights
► DN-27 is applied to the surface modification of MAH nanoparticles by grinding method. ► Hydrophobic PMMA-MAH particles are obtained by a simple one-pot in situ polymerization reaction. ► The thermal stability of the PMMA-MAH composite particles had been improved. ► The sample obtained possesses a higher water contact angle of 108°.
Introduction
In recent years, there has been a trend towards the use of halogen-free flame retardant because of its advantages, such as low smoke, no toxicity, and no carcinogenic gas generation [1], [2], [3]. Many investigations have demonstrated that magnesium hydroxide (MH), aluminum hydroxide (AH) and magnesium aluminum hydroxide (MAH) are environmentally friendly additives and can be used in polymer materials for manufacturing halogen-free and low-smoke cables [4], [5], [6], [7], [8], [9]. However, the above hydroxides exist some disadvantages, such as high loadings and poor compatibility with the polymeric materials, which degraded the mechanical properties [10], [11]. Therefore, it is very necessary to modify the surface of particles to improve their dispersion in polymers. The surface treating method using by low-molecular weight coupling agents or surfactants has been found to be reasonably effective [12], [13], [14], [15], [16], [17], [18]. But low-molecular weight compounds have a tendency to migrate out from the interface to the surface of the composites, inevitably, there is decrease in the mechanical and physical properties of the composite materials. Nowadays, polymer modification on inorganic particles has become a more interesting method to improve their dispersibility and compatibility in organic phrase and polymer composite [19], [20], [21]. Because of their layered structure and high anion-exchange capacity, MAH nanoparticles have attracted much attention [22], [23], [24], [25], [26], [27]. The intercalation of guest species in crystalline layered host matrices is considered to be a versatile synthetic method for the synthesis of nanostructured hybrid materials [28], [29]. However, there have been few reports on the surface grafting of MAH. On account of it is easy to get and prone to react [13], [30], MMA monomer was used in this experiment.
In the present paper, a novel type of phosphate coupling agent, DN-27 is first applied to the surface modification of MAH nanoparticles by grinding method, then hydrophobic PMMA-MAH particles are obtained by a simple one-pot in situ polymerization reaction.
Section snippets
Materials
The reagents that used in this work were listed in Table 1. All the above chemicals were analytically pure and used as received without further purification except MMA, which was distilled at a reduced pressure at 50 °C. AIBN was dissolved in DMF and recrystallized in ethanol twice for purification. DN-27 is a novel type of phosphate coupling agent and its formula can be expressed as ((CH3)2CHO)2P(O)O(CH2CH2O)10C6H4OC(O)C(CH3)CH2, which can be named as
DN-27 modification
Generally speaking, MAH nanoparticles are hard to graft MMA on their surface directly. In order to easily polymerize MMA monomer, DN-27 was used to modify the surfaces of the nanoparticles to introduce double bond. DN-27 is a novel type of phosphate coupling agent with unsaturated double bond. That makes it facilitate the polymerization of MMA monomers on MAH nanoparticles. Firstly, DN-27 coated in MAH nanoparticles by grinding reaction to introduce unsaturated double bond onto the surface of
Conclusions
MAH nanoparticles were obtained with the mean size of 80 nm and high purity. PMMA was grafted on the magnesium aluminum hydroxide nanoparticles after DN-27 modification. MMA monomers polymerized on the nanoparticle surfaces via the double bond of DN-27. The compatibility and the thermal stability of the PMMA-MAH composite particles had been improved greatly. This is very helpful to the flame retardant performance of magnesium aluminum hydroxide composite particles when added in the polymer
Acknowledgements
The work was financially supported by National Natural Science Foundation of China (No. 20873101), Natural Science Foundation of Gansu Province (No. 2007GS03562), Scientific Research Fund of Gansu Provincial Education Department (No. 1001-08) and Key Laboratory of Polymer Materials of Gansu Province.
References (31)
- et al.
Preparation of lamellar magnesium hydroxide nanoparticles via precipitation method
Powder Technol.
(2009) - et al.
Synthesis of ordered arrays of magnesium hydroxide nanoparticles via a simple method
Colloids Surf. A: Physicochem. Eng. Aspects
(2010) - et al.
A review of flame retardant polypropylene fibres
Prog. Polym. Sci.
(2003) - et al.
Microwave-assisted synthesis of fibre-like Mg(OH)2 nanoparticles in aqueous solution at room temperature
Mater. Lett.
(2004) - et al.
Preparation of submicron-sized Mg(OH)2 particles through precipitation
Colloids Surf. A: Physicochem. Eng. Aspects
(2005) - et al.
Effect of dispersion of nano-magnesium hydroxide on the flammability of flame retardant ternary composites
Compos. Sci. Technol.
(2007) - et al.
Effect of compatibilizers on thermal stability and mechanical properties of magnesium hydroxide filled polypropylene composites
Thermochim. Acta
(2009) - et al.
Synergistic effects of novolac-based char former with magnesium hydroxide in flame retardant polyamide-6
Polym. Degrad. Stab.
(2008) - et al.
Synthesis and characterization of superfine magnesium hydroxide with monodispersity
J. Cryst. Growth
(2008) - et al.
In situ preparation and surface modification of magnesium hydroxide nanoparticles
Colloids Surf. A: Physicochem. Eng. Aspects
(2009)
Hydrophobic magnesium hydroxide nanoparticles via oleic acid and poly(methyl methacrylate)-grafting surface modification
Powder Technol.
In situ synthesis of nanolamellas of hydrophobic magnesium hydroxide
Colloids Surf. A: Physicochem. Eng. Aspects
Surface treatment of magnesium hydroxide to improve its dispersion in organic phase by the ultrasonic technique
Appl. Surf. Sci.
Core-shell magnesium hydroxide/polystyrene hybrid nanoparticles prepared by ultrasonic wave-assisted in-situ copolymerization
Mater. Lett.
The investigation of using magnesium hydroxide as a flame retardant in the cable insulation material by cross-linked polyethylene
Mater. Des.
Cited by (32)
Flame retardant treatments for polypropylene: Strategies and recent advances
2021, Composites Part A: Applied Science and ManufacturingCitation Excerpt :The former mainly improves the interfacial bonding between the inorganic filler and the organic polymer by changing the surface properties of the inorganic filler through surface treatment, via adding the compatibilizer and through copolymerization or grafting of monomer to improve the interaction between the matrix and the filler. The interaction is mainly based on the degree of adhesion between the additive and the polymer matrix, such as coupling agents, polypropylene grafted maleic substitution (PP-g-MAH), alkyl silicone oil, polyvinyl alcohol [180-184]. The latter makes greater use of the synergism of flame retardants, such as the presence of nanomaterials and the addition of transition metals.
Highly efficient and selective removal of low-concentration antibiotics from aqueous solution by regenerable Mg(OH)<inf>2</inf>
2020, Journal of Environmental Sciences (China)Citation Excerpt :Therefore, it has been widely used to remove aromatic organic pollutants in aqueous solution. Actually, various adsorbents including carbonaceous materials, metallic oxides, and layered hydroxide have been applied with Aww (Yu et al., 2016; Guo et al., 2012; Sui et al., 2012). For example, it was reported that microporous activated carbon (ACC) with its unique porous structure and rich surface-active functional groups could adsorb multiple fluoroquinolone antibiotics in aqueous solution (ciprofloxacin (CIP), norfloxacin (NOR), etc.) (Fu et al., 2016).
Surface modification of magnesium hydroxide by wet process and effect on the thermal stability of silicone rubber
2019, Applied Surface ScienceCitation Excerpt :In addition, a high loading of MH is usually required to guarantee the desired flame retardant effect, which leads to sharply decline in the mechanical properties and rheological properties of the polymers [12–15]. Surface modification has been demonstrated as a simple and effective approach to afford MH with hydrophobicity and improve the dispersion stability of MH in polymers [16–18]. Among various modifier, silane coupling agent has attracted much attention due to its amphiphilicity [19–21].
Preparation of β-cyclodextrin-ester network and new organo-modified LDH as dual additives of PVA: Thermal, dynamic-mechanical and migration study
2017, Progress in Organic CoatingsCitation Excerpt :However, low-molecular weight agents have a propensity to migrate out from the interface to the surface of the composite and this phenomenon inevitably causes a decrease in the mechanical and physical properties of the composite materials. Therefore, theirmigration control from the composite materials is very important [25–31]. β-Cyclodextrin (β-CD) is a non-toxic cyclic oligosaccharide which is made of seven glucose units, linked by 1,4-α-glucosidic bonds, containing a hydrophilic outer surface and a hollow hydrophobic interior.
Surface modification of magnesium hydroxide using vinyltriethoxysilane by dry process
2016, Applied Surface ScienceCitation Excerpt :The on-line modification could short the process line and obtain ultrafine MH, due to modification and preparation of MH can be acted on simultaneously [17,18]. In the case of dry process and wet process methods, there are versatile surface modifiers, such as fatty acids, titanate coupling agent, silane coupling agents, and so on [19–22], can be chosen for prepared MH. Silane coupling agent has gained more research attention due to its unique structure, which contains two different functional groups: one that is attracted to the resin, and the other that reacts with hydroxyl groups on the surface of the filler [23–25].
Surface modification of titanium hydride with epoxy resin via microwave-assisted ball milling
2014, Applied Surface Science