High density polyethylene, HDPE composites

Sipiao et al. [37] studied the mechanical properties of high-density polyethylene (HDPE) composites reinforced with palm fiber-treated alkali solution. 

Y. Li, C. Hu and Y. Yu, Interfacial studies of sisal fiber reinforced high density polyethylene (HDPE) composites. Compos. A 39, 570-579 (2008). 

Panthapulakkal and Sain [10] reported that the water absorption of wheat straw-filled high-density polyethylene (HDPE) composite to be lower than corncob-filled HDPE and greater than corn straw-filled composite. The greater amount of water absorption recorded by corncob-filled composites was attributed to the greater amount of hemicellulose present in corncob. When used in composites, incorporation of com-patibilizer may decrease water uptake this may consequently enhance the mechanical properties of the composites upon being subjected to water. 

Plastic materials represent less than 10% by weight of all packagiag materials. They have a value of over 7 biUion including composite flexible packagiag about half is for film and half for botties, jars, cups, tubs, and trays. The principal materials used are high density polyethylene (HDPE) for botties, low density polyethylene for film, polypropylene (PP) for film, and polyester for both botties and films. Plastic resias are manufactured by petrochemical companies, eg. Union Carbide and Mobil Chemical for low density polyethylene (LDPE), Solvay for high density polyethylene, Himont for polypropylene, and Shell and Eastman for polyester. 

In order to illustrate the utility of model parameter interpretation, a data set containing NIR transmission spectra of a series of polymer films will be used [85]. In this example, films were extruded from seven different polymer blends, each of which was formulated using a different ratio of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) where the blend compositions were 0, 2.5, 5,10, 25, 50 and 100% HDPE. NIR spectra were then obtained for four or five replicate film samples at each blend composition. Figure 12.18 shows the NIR spectra that were obtained. 

We focus here on the polystyrene/high-density polyethylene (HDPE) system. We have studied this system in greater detail than any other and describe here the phase behavior of this system, the blend synthesis, and some mechanical properties of the composites. 

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). 

The authors [2] found, that in case of high density polyethylene (HDPE), modified by high disperse mixture Fe/FeO (Z), is observed strong extreme rise of stability to cracking expressed by the time up to fracture t50. So, if for the initial HDPE normative value Tsq.is equal to 10 hours, then for composition HDPE+Z with content Z Cz=0.05 mass.% the value t50 reaches 250 hours. The purpose of the present paper is the explanation of this important... 

The composition of feed polymers also has an important effect on the properties of products. In the experimental work of Miskolczi et al. commercial waste plastics from the packaging, electronic and automotive industry and the agriculture were used as raw materials. The samples contained high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), ethylene-propylene copolymer (EPC), polystyrene (PS), polyamide 6.6 (PA 6.6) and polyvinyl chloride (PVC). 

Figure 1.39 Polarized light micrograph of crystallized high density polyethylene (HDPE). (Reproduced with permission from J. Scheirs, Compositional and Failure Analysis of Polymers A Practical Approach, John Wiley Sons Ltd, Chichester. 2000 John Wiley Sons Ltd.)...

Most composite decking manufacturers utilize high-density polyethylene, (HDPE), polypropylene, or polyvinylchloride (PVC) as polymer matrix, and wood flour or rice hulls as the principal filler for their products. Some manufacturers also add mineral fillers, such as talc. These and other changes in compositions make composite materials to vary in their appearance, shape, strength, deflection, moisture absorption, fade resistance, microbial resistance, slip resistance, flammability, and other properties, which will be discussed later in this book. 

Here A is a time constant and is often interpreted as the relaxation time of the polymer, particularly in the filled composites. It significantly increases with wood flour content in filled high density polyethylene (HDPE) [4], The authors suggested that it is a result from the increased relaxation time of the reduced amount of polymer in the filled composite. 

Ground rubber tire was used as a partial substitute for EPDM rubber in modified EPDM—high-density polyethylene (HDPE) blends. The blends with higher rubber content showed poor processability, whereas the compositions with higher plastic content behaved like toughened plastics. It was observed that for the 60/40 rubber/ plastic blend, 50% of EPDM could be replaced by the ground rubber without deterioration in properties [58],... 

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