High-density polyethylene stabilization

Figure 5. High-density polyethylene (2% rutile Ti02, 0.5% LS). Elongation retention as a function of 45° south direct Florida exposure for high density polyethylene stabilized with 0.50% of various light stabilizers. Pigmented rutile TiOt.

Terpene monomers are another class of interesting natural monomers because they give, on polymerization, hydrocarbon therplastic resins that exhibit a high degree of tackiness useful in pressure sensitive tapes [25]. They are also used for sizing paper and textile materials. Terpene-phenol resins are effective heat stabilizers for high-density polyethylene. 

Storage stability Store DF in lead and wax-lined carboys, high-density polyethylene bottles, or nickel-lined containers in well-ventilated areas. Never store DF with alcohols DF will react with alcohols to form lethal chemicals, such as crude GB. Incompatible with water, glass, concrete, most metals, natural rubber, leather, and organic materials like glycols. The acidic corrosive hydrolysis products may react with metals, such as Al, Pb, and Fe, to give off hydrogen gas, a potential fire and explosive hazard. 

Chapter 661 of the USP provides criteria for the interchangeability of low- and high-density polyethylene for dry, oral dosage forms. In addition, there are standards for polyethylene terephthalate bottles and polyethylene terephthalate G bottles. USP criteria for interchangeability are listed in Table 17. These criteria allow usage of alternate materials in the same plastic class to be used prior to obtaining prior stability data. 

A second example is the yellow pyrazolone salt, Pigment Yellow 191 [129423-54-7]. It is the calcium salt of diazotized 2-amino-4-chloro-5-methyl-benzenesulfonic acid coupled with 3-methyl-1-[3 —sulfophenyl]-5-pyrazolone and provides a reddish yellow pigment for use in plastics applications. It shows very good heat stability and excellent resistance to nonpolar solvents and commonly used plasticizers (qv). It finds applications in high density polyethylene, polystyrene, and ABS, and shows satisfactory lightfastness. 

The mechanism of the UV stabilization of high-density polyethylene by nickel complexes has... 

Stabilities of lake and tap water samples for aluminium speciation were investigated (Fairman etal., 1994). Concentrations of 25-1000mgl 1 total aluminium in high-density polyethylene containers were stable for 30 days. Thereafter, increases in pH resulted in the precipitation of aluminium hydroxy species. 

A number of ortho hindered alkyl-substituted phenyl phosphites and phosphonites were found to be effective process stabilizers for polypropylene and high density polyethylene combining more effective stabilization activity at high temperatures with good storage stability at relatively elevated humidity and ambient temperature, as well as resistance to discoloration. 

In order to identify any excipient- and packaging-related impurities in the formulation, placebo cores and hlm-coated placebos, were prepared using the same excipients as in the active tablets. The placebo cores and film-coated placebos, as well as active cores and hlm-coated active tablets were set up on a stability study in high density polyethylene (HDPE) bottles with and without desiccant and in foil-foil blisters. At the designated time intervals, the tablets were tested for purity by gradient HPLC analysis. 

Hoojjat, P., Harte, B. R., Hernandez, R. J., Giacin, J. R., and Miltz, J. (1987). Mass transfer of BHT from high density polyethylene film and its influence on product stability. 

Figure 14.22 shows a line with examples of products. The basic plastic, usually polypropylene (PP) but also high-density polyethylene (PE-HD), and the additives required by the formulation (e. g coupling agent, UV stabilizer, pigment if required, antibacterial agent, or flame retardant), are added to the first barrel of the screw kneader by a gravimetric... 

Note-. 2 - sufficient thermal stability and limited reactivity with polymer allows broad use, 1 = marginal thermal stability or potential reactivity with polymer restricts use, 0 = generally unsuitable for use. FPVC, Flexible Polyvinyl Chloride RPVC, Rigid Polyvinyl Chloride PS, Polystyrene LDPE, Low Density Polyethylene HDPE, High Density Polyethylene PP, Polypropylene ABS, Acrylonitrile-butadiene-styrene copolymer PET, Polyethylene terephthalate PA, Polyamide PC, Polycarbonate... 

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... 

An additive system was developed for poly(vinyl chloride) for medical applications. The additives include primary stabilisers (Ca-Zn stearate and Zn stearate), secondary stabilisers (epoxides) and lubricants (ethylene bisamide and high density polyethylene), to improve melt processing and heat stability. The use of the stabilisers resulted in reduced equipment down-time, increased the level of recycled material which could be incorporated, and enhanced the product characteristics, including colour, clarity, blush, aqueous extractables and particle generation. 5 refs. 

Glass and plastic vessels (but not nitrocellulose centrifuge pots) can be dried in an oven at the following temperatures, which depend on the thermal stability of the material polyvinyl chloride 70 °C polystyrene 70 °C polyethylene 80 °C high density polyethylene 120 °C polyallomer 130 °C polypropylene 130 °C polycarbonate 135 °C teflon 180 °C and glass 200 °C. 

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