Primary polyolefins

A large number of hindered phenoHc antioxidants are based on the Michael addition of 2,6-di-/ f2 -butylphenol and methyl acrylate under basic catalysis to yield the hydrocinnamate which is a basic building block used in the production of octadecyl 3-(3,5-di-/ f2 butyl-4-hydroxyphenyl)propionate, [2082-79-3], tetrakis(methylene-3(3,5-di-/ f2 butyl-4-hydroxylphenyl)propionate)methane [6683-19-8], and many others (63,64). These hindered phenolic antioxidants are the most widely used primary stabilizers in the world and are used in polyolefins, synthetic and natural mbber, styrenics, vinyl polymers, and engineering resins. 2,6-Di-/ f2 -butylphenol is converted to a methylene isocyanate which is trimerized to a triazine derivative... 

D. Burdick, S. Laermer, S. Young, and P. Zambetti, "A New Primary Antioxidant System for Polyolefins," presented 2l. ddditives 95 Clearwater,... 

This difference in reactivity between the different classes of amines explains the difference in the primer performance on polyolefin substrates with ethyl cyanoacrylate-based adhesives [37J. Since primary and secondary amines form low molecular weight species, a weak boundary layer would form first, instead of high molecular weight polymer. Also, the polymer, which does ultimately form, has a lower molecular weight, which would lower adhesives strength [8,9]. 

The molecular structure and properties of polyolefins have been explained by several workers in the past [10-14]. This chapter deals with the primary molecular parameters and their effect on processability and ultimate properties of PEs. Since molecular parameters are closely interrelated, it is not possible to discuss one without referring to the other. Hence, in the section relating to the effect of chain branching, reference has also been made to MW and MWD and vice versa. 

Whereas PVA fleeces are used only in primary cells polyamide fleeces compete with polyolefin, preferably polypropylene fleeces. The latter are more stable at higher temperatures and do not contribute to electrolyte carbonation, but they wet only after a pretreatment either by fluorination [131] or by coating and crosslinking with hydrophilic substances (e.g., polyacrylic acid [132]) on the surface of the fiber. 

The OSM MAP can be effectively applied to most of the organic additives for polyolefins. Its validity has been tested by comparing the OSM with traditional reflux extraction procedures for primary AOs (phenols), secondary AOs (aliphatic and aromatic phosphites ... 

Products Driving forces Threats Phenolic primary AOs, organophosphite secondary AOs Global production of polyolefins None... 

NO Reactions. The most informative derivitization reaction of oxidized polyolefins that we have found for product identification is that with NO. The details of NO reactions with alcohols and hydroperoxides to give nitrites and nitrates respectively have been reported previously, and only the salient features are discussed here (23). The IR absorption bands of primary, secondary and tertiary nitrites and nitrates are shown in Table I. After NO treatment, y-oxidized LLDPE shows a sharp sym.-nitrate stretch at 1276 cm-1 and an antisym. stretch at 1631 cm-1 (Fig. 1), consistent with the IR spectra of model secondary nitrates. Only a small secondary or primary nitrite peak was formed at 778 cm-1. NO treatment of y-oxidized LLDPE which had been treated by iodometry (all -OOH converted to -OH) showed strong secondary nitrite absorptions, but only traces of primary nitrite, from primary alcohol groups (distinctive 1657 cm-1 absorption). However, primary products were more prominent in LLDPE after photo-oxidation. 

P.R.48 5, a magnesium salt, was a comparatively recent product but its manufacture has already been discontinued. It is considerably yellower and at the same time more brilliant than P.R.48 4. The pigment is also much weaker in white reductions. Compared to the manganese version, P.R.48 5 does not perform as well if exposed to light and/or weather, and it darkens in full shades. Its primary field of application is the pigmentation of polyolefins, but it is also employed to color PVC and polystyrene. Its application properties and fastness properties in print and in paints largely parallel those of P.R.48 2. 

All lithium based batteries use nonaqueous electrolytes because of the reactivity of lithium in aqueous solution and because of the electrolyte s stability at high voltage. The majority of these cells use microporous membranes made of polyolefins. In some cases, nonwovens made of polyolefins are either used alone or with microporous separators. This section will mainly focus on separators used in secondary lithium batteries followed by a brief summary of separators used in lithium primary batteries. 

As films are used e.g. the polymerization product of ethylbenzene and divinylbenzene (33) the copolymer of styrene and butadiene (755) the copolymer of styrene and butadiene mixed with polyethylene (157) a vulcanized or cyclized copolymer of an aromatic vinylcompound and an aliphatic conjugated polyene (2). As a crack resisting matrix is mentioned the copolymer of styrene, divinylbenzene and butadiene with e.g. dioctylphthalate as a plasticizer (176). Other examples are the copolymers of unsaturated aromatic compounds and unsaturated aliphatic compounds (77) and the reaction products of polyolefines and partially polymerized styrene (174). Primary groups can be introduced also with the help of Friedel-Crafts catalyst. Ts. Kuwata and co-workers treated a film of a copolymer of styrene and butadiene with an aluminium-ether complex and ethylenedichloride (79). Afterwards they allowed the film to react with trimethylamine. Another technique is the grafting of e.g. a polyethylene film with styrene (28). 

Photoantioxidants are typified by the class of HAS which although were developed for photostabilization of polyolefins, also possess thermal antioxidant properties. They are generally assumed to function as primary antioxidants in that they scavenge radicals and in particular, peroxy radicals. 

R + R. OH - RH + R. o flow a combination of primary and secondary antioxidants functions in a SCHEME2.8 Stabilizing polyolefin matrix.82 Some metal-chelate scavengers may also be based on activity of chain-breaking, a tertiary phenolic structure, thereby introducing two antioxidant properprimary antioxidants. ties into the same molecule. 

Although solution blending has only been used at the lab scale at this time, compared with the in situ process, it may be more industrially friendly, particularly for the primary polymer producers who have operations, which can easily recover and recycle the solvent. High dilution is required and this may have an effect on the production of the PNs and the process is quite dependent on the individual polymer. Some polymers have many solvents from which to choose while others do not. A typical example is polystyrene, which can dissolve in a variety of solvents, so it is easy to find a solvent that is compatible with both the clay and the polymer. Polyolefins, on the other hand, require high boiling solvents and the high temperature may exert an effect of thermal degradation on the modifier. 

FR polyolefins find application in building wires, industrial control cables, automotive primary wire, and data cables. Specifications for thermoplastic building wire are found in UL-83 Thermoplastic-Insulated Wires and Cables for temperature ratings of 75°C and 90°C in wet and dry environments.51 Specification for industrial control cables are found in UL-44... 

In this study we have compared the effects of a treatment of a simple polyolefin (PP) in a variety of AC plasma s with that of air corona. The primary purpose was to investigate, as in the first part of this paper, whether static SIMS can be used to increase the understanding of such modified surfaces. The actual chemistry that takes place at the surface of this and other polyolefins will be published in more detail elsewhere. 

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