Maleated polyethylene

Specialty waxes include polar waxes for more polar adhesive systems. Examples would be castor wax (triglyceride of 12-hydroxy stearic acid) or Paracin wax N- 2 hydroxy ethyl)-12-hydroxy stearamide) which are used in polyester, polyamide, or with high VA EVA copolymer-based systems. Other common polar waxes are maleated polyethylenes, which are used to improve the specific adhesion of polyethylene-based adhesives, and low molecular weight ethylene copolymers with vinyl acetate or acrylic acid, which are used to improve low temperature adhesion. High melting point isotactic polypropylene wax (7 155°C) and highly refined paraffin wax (7,n 83°C) are used where maximum heat resistance is critical. Needless to say, these specialty waxes also command a premium price, ranging from 2 to 5 times that of conventional paraffin wax. 

Composite formulations were prepared as follows The straw samples as received from INEEL were ground to 0.69 mm in a hammer mill and oven dried to 1.1% moisture. The dried straw samples were then blended with various amounts of high-density polyethylene (HDPE), lubricants, and maleated polyethylene blends (MAPE) (see Table 2). The mixed formulations were then extruded with a 35-mm Cincinnati Milacron Model CMT 35 counterrotating conical twin screw extruder (Cincinnati Milacron, Batavia, OH), which produced a 9.525 x 38.1 mm2 solid cross-section. Flexural strength, density, and water sorption were measured for the extruded samples according to ASTM Standard Methods (13,14). 

Near infrared spectroscopy (NIRS) of WPC material with maleated polyethylene and polypropylene showed no obvions differences with conpling agent addition ... 

T.J. Keener. New maleated polyethylene (MaPE) couplers. In Seventh International Conference on Woodfiber-Plastic Composites, Madison, WI, May 19, 2003. 

Wood flour from maple, 120 mesh, vacuum dried. The coupling agent was maleated polyethylene containing 1% (w/w) grafted maleic anhydride (Epolene G-2608, Eastman Chemicals). The lubricant was alkene bis fatty amid (Glycolube WP-2002, Lonza Inc.) [4]. 

G.-M. Lin, G.-X. Sul, R. Yang, Mechanical and shape-memory properties of polyamide/maleated polyethylene/linear low-density polyethylene blend. J. Appl. Polym. Sci. 126, 350-357 (2012)... 

Li et al. reported that immiscible high-density polyethylene (HDPE)/ poly(ethylene terephthalate) (PET) blends, prepared by means of melt extrusion with ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) terpoly-mer as a reactive compatibilizer, can exhibit shape memory effects [32]. They observed that the compatibilized blends showed improved shape memory effects along with better mechanical properties as compared to the simple binary blends. In the blend, HDPE acts as a reversible phase, and the response temperature in the shape recovery process is determined by of HDPE. The shape-recovery ratio of the 90/10/5 HDPE/PET/EBAGMA blend reached nearly 100%. Similar behavior was observed for immiscible HDPE/ nylon 6 blends [33]. The addition of maleated polyethylene-octene copolymer (POE-g-MAH) increases compatibility and phase-interfacial adhesion between HDPE and nylon 6, and shape memory property was improved. The shape recovery rate of HDPE/nylon 6/POE-g-MAH (80/20/10) blend is 96.5% when the stretch ratio is 75%. 

Xie, Y., Yu, D., Kong, J., Fan, X., and Qiao, W. 2006. Study on morphology, crystallization behaviors of highly filled maleated polyethylene-layered silicate nanocomposites. Journal of Applied Polymer Science 100 4004-4011. 

HDPE/bamboo composites with different nanoclay and maleated polyethylene (MAPE) contents were fabricated by melt compounding. The compounding characteristics, clay dispersion, HOPE crystallization, and mechanical properties of the composites were studied. The X-ray diffraction (XRD) data showed that the clay was exfoliated only when 1% clay was added to pure HOPE wifliout MAPE. For HDPE/bamboo systems, MAPE was necessary to achieve clay exfoUatiOTi. For the HDPE/bamboo fiber composites, tensile strength, bending modulus, and strength were improved with the use of MAPE however, the use of the clay in the system led to reduced mechanical properties [27]. 

Table 16.3 Properties of injection molded maleated polyethylene containing different fillers [15].

Figure 16.2 SEM fracture surface of injection molded specimen showing improved adhesion between the maleated polyethylene matrix and the untreated calcium carbonate [15].

Maleated or acrylic acid grafted polypropylene can also be used as a coupling agent for these types of compounds. The use of maleated polyethylene and polypropylenes in this application is widely documented. Jancar (36) conducted a study of maleated polypropylene in Mg(OH)2 filled polypropylene. Their findings indicated a critical concentration of carboxylic acid groups. At low levels of addition, the composite yield stress increased sharply. However, at a certain concentration based on filler content, very little increase in yield stress was observed with increased addition of PPgMAH. The possible explanations give for this were... 

Further indication of the importance of a proper dispersion of layered silicates in PNCs is provided by Ranade et al [21] in a study reporting a com-pai ison between the creep behavior of maleated and non-maleated polyethylene-montmorillonite layered silicate blown films. The authom claimed that maleated polyethylene (PE-g-MA) facilitated the dispersion of montmorillonite layered silicate in the polyethylene (PE) matrix. The creep experiments were perfonned at 25% and 50% of the yield stress and the resulting creep compliance was modeled with the Burgers model. The fitting parameters of the Burgei-s model for the creep behavior (evaluated at 50% of the yield stress) of neat PE matrix and relative PNCs are summarized in Table 9.2. 

Ranade A, Nayak K, Fairbrother D and D Souza N A (2005) Maleated and non-maleated polyethylene-montmorillonite layered silicate blown films creep, dispersion and crystallinity. Polymer 46 7323-7333. 

As we have indicated above the presence of these block and graft copolymers at the interface between two polymer melts has a substantial influence on the interfacial tension between the two melt phases (see Section 5.7). This effect has been investigated by various researchers [26, 44 to 47]. Typical results are shown in Table 6.1 for the polyethylene-poly(ethylene terephthalate) system [47]. This indicates that block copolymers where the two segments dissolve in different melt phases cause substantial reductions in interfacial tension. This also is the case when the block/graft copolymer are added they are chemically react with the molecules of one of the phases as in the case of the maleated polyethylene and maleated ethylene copolymers with polyamides or polyesters in blends with polyolefins. 

A Ramezani Kakroodi, Y Kazemi, and D Rodrigue. Mechanical, rheological, morphological and water absorption properties of maleated polyethylene/ hemp composites Effect of ground tire rubber addition. Composites Part B. 51,337-344 (2013). 

Chem. Descrip. Maleat polyethylene wax (> 99%), modifiers/additives (< 1%) and maleic anhydride (< 0.1%)... 

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