Polyolefin HDPE

The attachment of trialkoxysilane functionality to polyolefins (HDPE, LDPE, PP) though grafting of vinylsilanes (e,g. 40, 41) or silane functional acrylates (e.g. 42) has been widely studied. 63 The principal application of these materials is the... 

Low-temperature pyrolysis for feedstock recovery 500-600 Single or mixed polyolefins (HDPE, LDPE, PP, PS, PVC), SB rubber Nitrogen liquid-free pyrolysis gas Broad spectrum of products (C1-C50). The gas yield is generally low with respect to waxes and oils [9, 14, 16, 26, 27, 28]... 

High -temperature pyrolysis for feedstock recovery 650-800 Polyolefins (HDPE, LDPE, PP, PVC), SB rubber, ABS, PA, PTFE,. .. Nitrogen steam Gas yield is generally high High content of olefins [8, 9, 16, 19, 28, 29, 30, 31]... 

Figure 13.7 shows the recovery of polyolefins (HDPE, LDPE, and PP) from several plastic waste. Very high polymer recovery was observed for all the plastic waste and proven that pure polymer can be easily recovered from plastic waste by this technique. Both solid and liquid fractions of the recovered polymer mainly consist of aliphatic hydrocarbon (a series of alkenes and alkynes) and can be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels. 

Mixed polyolefins (HDPE, LDPE, Pyrolysis catalyzed by Ga-ZSM-5 has 50% liquid fraction, predominantly... 

The properties of commodity and engineering thermoplastics can be boosted by compounding with mineral fibres and a special compatibilizer, report two Dutch companies, Bennet BV and Lapinus Fibres BV. Polyolefins (HDPE and PP copolymer) and polyamide 6 have been successfully upgraded with 35 and 2 5% respective addition of Rockfil fibres and Bennet compatibilizer. Tests in conjunction with injection moulder Heudijk Kunststoffen BV and masterbatch producer Curver Colour Department indicated that mechanical, stability and processability properties are improved, with improved heat distortion and FR performance, good surface finish and recyclability. 

ASTM committees have dealt with standard test methods to determine the oxidative properties of materials (c/r. ASTM D 3350, 3895, 4565, 5483, 5885 and E 1858). ASTM E 1858-97 (DSC-OIT) can be used to determine the oxidative behaviour of polyolefins (HDPE) and hydrocarbon oils (diluted engine pass oil blend). This method is precise. There is a good correlation between DSC/TGA-OOT in air/02 (ASTM E 2009-99) and PDSC-OIT (ASTM E 1858-97) under high-pressure oxygen for polyolefins. The ASTM method D 3895-92 for DSC-OIT and DSC-OIT has recently been modified into a generalised technique with considerably expanded... 

Glycostat was developed for use as a nonionic thermoplastic resin antistatic agent. It is suggested for use in Polyolefins HDPE, LOPE, Polypropylene PVC... 

Polyolefins (HDPE/LDPE/PP) Polyvinyl chloride (PVC) Polyacrylonitrile (PAN)... 

There are three basic types of polyethylene foams of importance (/) extmded foams from low density polyethylene (LPDE) (2) foam products from high density polyethylene (HDPE) and (J) cross-linked polyethylene foams. Other polyolefin foams have an insignificant volume as compared to polyethylene foams and most of their uses are as resia extenders. 

Recycling of HDPE. Polyolefins, including HDPE, are the second most widely recycled thermoplastic materials after PET (110). A significant fraction of articles made from HDPE (mostly bottles, containers, and film) are collected from consumers, sorted, cleaned, and reprocessed (110—113). Processing of post-consumer HDPE includes the same operations as those used for virgin resins blow mol ding, injection molding, and extmsion. 

Polyolefins are manufactured and used in much greater quantity than any other class of plastics. The principal polyolefins are polyethylenes of various densities (LDPE, LLDPE, HDPE) and polypropylene (PP) (see Olefin polymers). 

Coran and Patel [74] investigated the reactive com-patibilization of PP-NBR and HDPE-NBR blends using phenolic modified polyolefin, maleic anhydride modified polyolefin, and amine terminated nitrile rubber as reactive components. Dynamic vulcanization was also inves-... 

The reactive compatibilization of HDPE-NBR and PP-NBR blends has been studied by Thomas and coworkers [75,76]. The maleic anhydride modified polyolefins and phenolic modified polyolefins are used as com-patibilizers. The effect of the concentration of these compatibilizers on the compatibility of these blends was investigated in terms of morphology and mechanical properties. It was found that in these blends an optimum quantity of the compatibilizer was required to obtain maximum improvement in properties, and after that a leveling off was observed. The domain size of the dispersed NBR phase in these blends is decreased up to a certain level and then increases (Fig. 12 and 13). The reduction in domain size is attributed to the increase in... 

When polyethylene was first produced in the early 1940s, physicists in England, USA, and Germany predicted a tremendous potential for it. At that time the properties of PEs were much lower than those presently available. Out of that original general-purpose PE, have been developed specific PEs in this polyolefin family of plastics such as LDPE, HDPE, UHMWPE, and so on. In turn their different properties, as well as other plastics, continually increase and their variables continue to be reduced and/or easier to process to tighter tolerances. 

Dow ABS Nylon 6/6 Polycarbonate Polyethylene, HDPE, LDPE, LLDPE, ULDPE Polypropylene HPPP, CPPP Polystyrene HIPS, GPPS, Recycled, Advanced Styrenic Resin SAN Polyurethane Elastomers Polyolefin Plastomer PC/ABS Crystalline Polymer ABS/TPU... 

The metal catalyzed production of polyolefins such as high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and polypropylene (PP) has grown into an enormous industry. Heterogeneous transition metal catalysts are used for the vast majority of PE and all of the PP production. These catalysts fall generally within two broad classes. Most commercial PP is isotactic and is produced with a catalyst based on a combination of titanium chloride and alkylaluminum chlorides. HDPE and LLDPE are produced with either a titanium catalyst or one based on chromium supported on silica. Most commercial titanium-based PE catalysts are supported on MgCl2. 

Figure 3.14 Microwave extraction of 0.1 % Irganox 1010 from ground (20 mesh) polyolefins ( , PP O, LDPE +, HDPE) with 1,1,1-trichloroethane. After Freitag and John [96]. From W. Freitag and O. John, Angewandte Macromoleculare Chemie, 175, 181-185 (1990). Wiley-VCH, 1990. Reproduced by permission of Wiley-VCH...

Although PFE lacks a proven total concept for in-polymer analysis, as in the case of closed-vessel MAE (though limited to polyolefins), a framework for method development and optimisation is now available which is expected to be an excellent guide for a wide variety of applications, including non-polyolefinic matrices. Already, reported results refer to HDPE, LDPE, LLDPE, PP, PA6, PA6.6, PET, PBT, PMMA, PS, PVC, ABS, styrene-butadiene rubbers, while others may be added, such as the determination of oil in EPDM, the quantification of the water-insoluble fraction in nylon, as well as the determination of the isotacticity of polypropylene and of heptane insolubles. Thus PFE seems to cover a much broader polymer matrix range than MAE and appears to be quite suitable for R D samples. 

Oligomeric hindered amine light stabilisers, such as Tinuvin 622 and Chimassorb 944, resist satisfactory analysis by conventional HPLC and have required direct UV spectroscopic analysis of a polyolefin extract [596], PyGC of an extract [618,648], or SEC of an extract [649]. Freitag et al. [616] determined Tinuvin 622 in LDPE, HDPE and PP by saponification of the polymer dissolution in hot toluene via addition of an... 

LDPE or HDPE extracts has been determined colorimet-rically at 430 nm by oxidation with H202 in the presence of H2S04 [66]. p-Phenylenediamine derivatives such as Flexzone 3C, used as antiozonants in rubber products, have been determined colorimetrically after oxidation to the corresponding Wurster salts [67]. A wide range of amine AOs in polyolefins has been determined by the p-nitroaniline spectrophotometric procedure [68]. Monoethanolamine (MEA) in a slip agent in PE film has been determined as a salicylaldehyde derivative by spectrophotometric quantification at 385 nm [69]. Table 5.6 contains additional examples of the use of 1JV/VIS spectrophotometry for the determination of additives in polymers. 

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