Polymer polypropylene

Polypropylene polymers are typically modified with ethylene to obtain desirable properties for specific applications. Specifically, ethylene—propylene mbbers are introduced as a discrete phase in heterophasic copolymers to improve toughness and low temperature impact resistance (see Elastomers, ETHYLENE-PROPYLENE rubber). This is done by sequential polymerisation of homopolymer polypropylene and ethylene—propylene mbber in a multistage reactor process or by the extmsion compounding of ethylene—propylene mbber with a homopolymer. Addition of high density polyethylene, by polymerisation or compounding, is sometimes used to reduce stress whitening. In all cases, a superior balance of properties is obtained when the sise of the discrete mbber phase is approximately one micrometer. Examples of these polymers and their properties are shown in Table 2. Mineral fillers, such as talc or calcium carbonate, can be added to polypropylene to increase stiffness and high temperature properties, as shown in Table 3. 

The 1997 U.S. propylene demand ws 31 billion pounds and most of it was used to produce polypropylene polymers and copolymers (about 46%). Other large volume uses are acrylonitrile for synthetic fibers (Ca 13%), propylene oxide (Ca 10%), cumene (Ca 8%) and oxo alcohols (Ca 7%). ... 

Cook, R.F., Koester, K.J., Macosko, C.W., and Ajbani, M. Rheological and Mechanical Behavior of Blends of Styrene-Butadiene Rubber with Polypropylene, Polym. Eng. Set 45(11), 1487-1497, 2005. 

Phadke, A.A. and De, S.K., Effect of cryo-ground rubber on melt flow and mechanical properties of polypropylene, Polym. Eng. Sci., 26, 1079, 1986. 

New Orleans, La., August 1999, p.752-3 POLYSTYRENE/POLYPROPYLENE POLYMER BLEND COMPATIBILISATION WITHOUT ADDITION OF PREMADE BLOCK OR GRAFT COPOLYMERS OR FUNCTIONALISATION Furgiuele N Khait K Torkelson J M (ACS,Div.of Polymer Chemistry)... 

Polypropylene polymers are typically modified with ethylene to obtain desirable properties for specific applications. Specifically, ethylene-propylene rubbers are introduced as a discrete phase in heterophasic copolymers to improve toughness and low temperature impact resistance. 

Miller, R. L. On the existence of near-range order in isotactic polypropylenes. Polymer 1, 135 (1960)... 

Nakafuku, C. High pressure d.t.a. study on the melting and crystallization of isotactic polypropylene. Polymer 22, 1673 (1981)... 

Mclnemey LF, Kao N, Bhattacharya SN (2003) Melt strength and extensibility of talc-filled polypropylene. Polym Eng Sd 43 1821-1829... 

Gijsman, P. Gitton, M. Hindered amine stabilizers as long-term heat stabilizers for polypropylene. Polym. Degrad. Stab. 1999, 66, 365— 371. 

Propylene (C3H6) is a gas with chemical, physical, and toxicological properties very similar to those of ethylene. It, too, is a simple asphyxiant. Its major use is in the manufacture of polypropylene polymer, a hard, strong plastic from which are made injection-molded bottles, as well as pipes, valves, battery cases, automobile body parts, and rot-resistant indoor-outdoor carpet. 

Yandenburg et al. [92] compared extraction of additive Irganox 1010 from freeze-ground polypropylene polymer by pressurized fluid extraction (PFE) and MAE with reflux, ultrasonic, shake-flask, and Soxhlet extraction. PFE and MAE were faster than any conventional method with comparable extraction efficiency. The times to reach 90% recovery by PFE using propan-2-ol at 150°C and acetone at 140°C were 5 and 6 minutes, respectively. Reflux with chloroform was found to be the fastest method performed under atmospheric pressure with 90% recovery in 24 minutes. Reflux with cyclohexane propan-2-ol (1 1) required 38 minutes. Ultrasonic, shake-flask, and Soxhlet extraction required about 80 minutes (90%) extraction). The total sample preparation time for PFE was 15 minutes, MAE 28 minutes, and reflux with chloroform was 45 minutes. 

Kaspersma, J. Doumen, C. Munro, S. Prins, A. M. Fire retardant mechanism of aliphatic bromine compounds in polystyrene and polypropylene, Polymer Degradation and Stability, 2002, 77(2), 325-331. 

Liu, Y. and Wang, Q. 2006. Catalytic action of phospho-tungstic acid in the synthesis of melamine salts of pentaerythritol phosphate and their synergistic effects in flame retarded polypropylene. Polym. Deg. Stab. 91 2513-2519. 

Chen, Y.H. and Wang, Q. 2007. Reaction of melamine phosphate with pentaerythritol and its products for flame retardation of polypropylene. Polym. Adv. Technol. 18 587-600. 

Li, B. and Xu, M. 2006. Effect of a novel charring-foaming agent on flame retardancy and thermal degradation of intumescent flame retardant polypropylene. Polym. Deg. Stab. 91 1380-1386. 

Fina, A., Abbenhuis, H.C.L., Tabuani, D., and Camino, G., Metal functionalized POSS as fire retardants in polypropylene, Polym. Degrad. Stab. 2006, 91, 2275. 

S. Nie, Y. Hu, L. Song, S. He, and D. Yang, Study on a novel and efficient flame retardant synergist nanoporous nickel phosphate VSB-1 with intumescent flame retardants in polypropylene, Polym. Adv. Technol., 2008, 19 489 195. 

Tochacek J and Sedlar J (1995)Hydrolysis and stabilization performance of bis(2,4-di-/m butyl phenyl )-pentaerythrityl diphosphite in polypropylene, Polym Degrad Stab 50 345-352. 

Farrow, G. Crystallinity, Crystal Size" and melting point of polypropylene. Polymer 4, 191-197 (1963). 

A new technique for following rapid rates of crystallization. II. Isotactic polypropylene. Polymer 3, 35—42 (1962). 

Differential Scanning Calorimetry. A Perkin-Elmer Model DSC-IB calorimeter was used to examine crystallinity by measuring areas under the fusion curve as a function of elastomer composition and processing variables. Areas of endotherms were calibrated against an indium standard and the crystallinity calculated using a value of —138 J/g for a 100% crystalline polypropylene polymer (II). 

Fig. 12.21. Diagrams showing (a) irregular atactic, (b) stereoregular isotactic, and (c) stereoregular syndiotactic configurations in polypropylene polymer. (Source Ahmed, M., "Polypropylene Fibers-Science andTechnology," Textile Science and Technology, 5, 16, Elsevier Science Publishers SV, Academic Publishing Div., New York, Amsterdam (1982).) Copyright M. Ahmed. By permission.

Product The process can produce a broad range of polypropylene polymers, including homo-polymer, random copolymer and impact copolymer, which become high-quality grades that can cover various applications. 

Figure 5.34. Tacticity vs. bulk properties for polypropylene polymers. The homogeneous" and heterogeneous notations refer to whether the entire polymer chains, or only regions, are of a certain tacticity.

One other example of a pyrogram of a copolymer is that for poly(propylene-gra/f-maIeic anhydride) or poIypropylene-gra/f-poly[3-(1-methyl-1-propenyl)-3,4-dihydrofuran-2,5-dione, CAS 107001-49-0. The polypropylene polymer was isotactic and had a low content of maleic anhydride (MA) and a M = 9,100. The pyrolysis was performed in conditions similar to other examples, at 600° C in He with separation of a Carbowax column. The results are shown in Figure 6.1.24. 

Not only polyethylene can be synthesized, but also many kinds of copolymers and elastomers, new structures of polypropylenes, polymers and copolymers of cyclic olefins. In addition, polymerization can be performed in the presence of fillers and oligomerization to optically active hydrocarbons is possible. For recent reviews and books see [17-20]. 

Bagheri, R. Chakraborty, K.B. Scott, G. Mechanisms of antioxidant action behavior of a hindered piperidine and related oxidation products during processing and photo-oxidation of polypropylene. Polym. Deg. Stab. 1982, 4 (1), 1-16. 

Al-Malaika, S. Goodwin, C. Issenhuth, S. Burdick, D. The antioxidant role of a-tocopherol in polymers II- melt stabilizing effect in polypropylene. Polym. Deg. Stab. 1999, 64 (1), 141-156. 

Bauer, L Habicher, W.D. Rauteneberg, C. et al. Antioxidant interaction between organic phosphites and hindered amine light stabilizers during processing and thermoxidation of polypropylene. Polym. Deg. Stab. 1995, 48 (3), 427-440. 

Norton, D.R. Keller, A. The spherulitic and lamellar morphology of melt crystallized isotactic polypropylene. Polymer 1985, 26, 704. 

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