Polypropylene compound

In broad tonnage terms the injection moulding markets for high-density polyethylene and polypropylene are very similar. The main reasons for selecting polypropylene have been given above. In favour of HDPE is the inherently better oxidation and ultraviolet resistance. Whilst these properties may be greatly improved in polypropylene by the use of additives these may increase the cost of polypropylene compounds to beyond that which is considered economically attractive. It is for this reason that HDPE has retained a substantial part of the crate market. 

Table 2-4 Examples of flexural modulus of elasticity for polypropylene compounds...

So far there has been little use in the volume thermoplastics such as PVC and polyolefins. The main exception would seem to be the use of amino-silane treated glass in conjunction with maleated polypropylene in polypropylene compounds. 

FIGURE 7.3 Temperature profiles for polypropylene compounds containing increasing loadings of magnesium oxide filler. (From Hornsby, P.R. and Watson, C.L., Plast. Rubber Process. Appl., 11, 45, 1989. With permission.)... 

An Investigation of Multi-angle Spectrophotometry for Colored Polypropylene Compounds... 

Glogovsky J. Softell—opening new dimensions and possibilities with soft touch polypropylene compounds. TPO Global Conference, conference proceedings. Society of Plastics Engineers 2008. 

S. Moritomi, W. Tsuyoshi, K. Susumu, Polypropylene Compounds for Automotive Applications (Sumitomo Chemical Co. Ltd, Tokyo, 2010)... 

Albano C. Reyes J. Ichazo M. Gonzalez J. Brito M. Moronta D. Analysis of the mechanical, thermal and morphological behavior of polypropylene compounds with sisal fibre and wood flour, irradiated with gamma rays. Polymer Degradation and Stability, vol.76, (2002), pp. 191-203. 

Standard test method for environmental stress-cracking of ethylene plastics Insulating and sheathing materials of electric and optical cables - Common test methods - Part 4-1 Methods specific to polyethylene and polypropylene compounds - Resistance to enviromnental stress cracking - Measurement of the melt flow index - Carbon black and/or mineral filler content measurement in polyethy-lene by direct combustion - Measurement of carbon black content by thermogravimetric analysis (TGA) - Assessment of carbon black dispersion in polyethylene using a microscope... 

There was little discussion of this perspective during the next 25 years, and only in the 1960s was there renewed attention. In 1962, Zakharenko et al. [Zl] in Moscow reported shear flow measurements of rubber-carbon black compounds. In 1972, Vinogradov et al. [V8], also in Moscow, reported similar results for other rubber-carbon black compounds and indicated the occurence of yield values. At the same time similar behavior was reported for talc-polypropylene compounds by Chapman and Lee [C8] of Shell and for titanium dioxide-polyethylene compounds by Minagawa and White [M29]. 

Unsaturated fatty acid oligomers, such as oligomerised oleic acid, are becoming increasingly available. Oligomer acids are claimed to be more effective than simple fatty acids for the treatment of ATH and magnesium hydroxide for use in FR polypropylene compounds. Ricinoleic acid, made from castor oil, is also said to be effective in this application. 

The multiple functions of mica have been outlined in Chapter 1 of this book, along with an example of its role in the search of multifunctional fillers for polypropylene compounds for automotive applications. Mica-reinforced thermoplastics such as polypropylene, polyethylene, nylon, and polyesters are now established in a variety of automotive applications and consumer products where mica supplements or replaces glass fibers and other mineral fillers. The wider use of mica in many applications has been limited by low impact strength and low weld-line strength in certain plastics. These issues are the focus of continuing R D efforts by materials suppliers and compounders/molders. 

Figure 9.20 Illustration of long glass fiber-reinforced polypropylene compounds by (a) melt and (b) powder impregnation process. (From Ref. 173, 1992, with permission from Elsevier Soience.)...

The decrease is large when nylon is blended with PP and smaller when PP is blended with nylon. Comparing the composite properties, the long fiber polypropylene compounds can easily double the flexural modulus and Izod impact strengths over the corresponding short fiber polypropylene compounds... 

X Leguet, M Ericson, D Chundury, G Baumer. Filled and Reinforced Polypropylene Compounds as Alternatives to Engineering Resins. ANTEC, SPE, Toronto,... 

Tables 14.17,14.18, and 14.19 show that addition of mica to polypropylene compounds has a negative effect on Izod impact properties. In each of the three resin systems, Izod impact decreases steadily with increasing amounts of mica. In homopolymer composites (Table 14.17), the largest particle size mica product, L-...

Polypropylene compounds are available in many grades and through many suppliers. Several of the major suppliers of PP molding compounds are Exxon Polymers (Escorene), Solvay (Fortliene), Aristech, Montell N.A. (Pro-fax), Discas (Reprean), Huntsman (Rexene), Amoco, TCA Plastics (Tonen), General Polymers (HiVat), Du Pont (Bynel), and Phillips Sumika (Marlex). 

Applied Market Information (1996) Polypropylene compounds in Western Europe. 

Coating is increasingly used to enhance the properties of fillers. One of the most widely used materials is stearic acid. Metal stearates are particularly effective as coatings for reactive particulate fillers, such as magnesium hydroxide (MH), producing polypropylene compounds with better impact resistance than those containing uncoated, or stearic acid-coated fillers. 

Polypropylene compounds reinforced with flax and glass mat. at comparable fibre contents, have similar fatigue strengths when exposed to dynamic repeated tensile stresses. The flax fibre composites are characterized by their high material damping, which is attributable to the specific properties of flax fibres. Tests at... 

Fig. 14. Short shots with two-color iiyection molding of a filled polypropylene compound. Reproduced from Ref. 55. Courtesy of the Society of Rheolc. ...

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