Environmental stress cracking poly

Many engineering thermoplastics (e.g., polysulfone, polycarbonate, etc.) have limited utility in applications that require exposure to chemical environments. Environmental stress cracking [13] occurs when a stressed polymer is exposed to solvents. Poly(aryl ether phenylquin-oxalines) [27] and poly(aryl ether benzoxazoles) [60] show poor resistance to environmental stress cracking in the presence of acetone, chloroform, etc. This is expected because these structures are amorphous, and there is no crystallinity or liquid crystalline type structure to give solvent resistance. Thus, these materials may have limited utility in processes or applications that require multiple solvent coatings or exposures, whereas acetylene terminated polyaryl ethers [13] exhibit excellent processability, high adhesive properties, and good resistance to hydraulic fluid. 

For crystalline polymers, however, not only the molecular weight and poly-dispersity index are of interest. Besides the degree of crystallinity, there is a specific influence of chain design, i.e., existence, length, and concentration of side chains on the resistance against environmental stress cracking, as will be pointed out in the next section. 

Kawaguchi T, Nishimura H, Miwa F, Abe K, Kuriyama T, Narisawa I (1999) Environmental stress cracking of poly(acrylonitrile-butadiene-styrene). Polym Eng Sci 39(2) 268—273... 

Ishiyama C, Sakuma T, Shimojo M, Higo Y (2002) Effects of humidity on environmental stress cracking behavior in poly(methyl methacrylate). J Polym Sci Part B Polym Phys 40(1) 1—9... 

Moskala EJ (1998) A fracture mechanics approach to environmental stress cracking in poly (ethyleneterephthalate). Polymer 39(3) 675-680... 

Bishop S, Isaac DH, Hinksman P, Morrissey P (2000) Environmental stress cracking of poly(vinyl chloride) in alkaline solutions. Polym Degradat Stabil 70(3) 477-484... 

Maccone P, Brinati G, Arcella V (2000) Environmental stress cracking of poly(vi-nylidene fluoride) in sodium hydroxide effect of chain regularity. Polym Eng Sci 40(3) 761-767... 

THE ENVIRONMENTAL STRESS CRACKING OF A PBT/PBA CO-POLY(ESTER ESTER)... 

Preliminary research has indicated that a PBT/PBA co-poly(ester ester) is susceptible to environmental stress cracking in water and in phosphoric acid solution, in both cases at 80°C. Time-to-Failure creep experiments were initiated to obtain quantitative data. These tests were performed in water and phosphoric acid solutions (pH = 1.6) at 80°C with notched tensile specimens under constant load (ranging from 0.6-7 MPa). The results have shown that the phosphoric acid solution decreases the lifetime when compared to tests done in water. Both environments decrease the lifetime tremendously when compared to creep tests in air. 

The influence of water on the environmental stress cracking of the PBT/PBA co-poly(ester ester) can be of a physical and /or chemical nature. The influence of acid, however, must be chemical because just having a small quantity of acid (11.4 g/1) in water will not influence the physical properties but it will decrease the time to failure up to a factor of 10 when compared to pure water. 

Environmental Stress Cracking (ESC), Thermoplastic Elastomer (TPE), Creep, Time-to-Failure, Hydrolysis, Co-poly(ester ester), Poly(butylene terephthalate), Poly(butylene adipate). 

The Environmental Stress Cracking of a PBT/PBA Co-poly(ester ester)... 

When heated. PP dissolves in nonpolar solvents with solubility param eters in the range of 6.5 to 9.5 H, but it is resistant to polar solvents, such as ethanol. PP is more resistant to environmental stress cracking than poly ethylene. 

The polysulfones form another large group, and some of the commercially important structures are shown in Table 15.10. Poly(phenylene sulfone) tends to be too intractable for easy processing, and the copolymer structures are more useful. These are usually amorphous materials with high values, typically in the range of 465 to 560 K. They are thermally stable, show good mechanical properties — particularly creep resistance — and are resistant to attack by dilute acids and alkahs. They can, however, dissolve in polar solvents, and solvent attack may also cause environmental stress cracking. 

Bub Bubeck, R. A Kinetics of environmental stress cracking in high density polyethylene. Poly- mer... 

Zho Zhou, H. X., Lofgren, E. A., Jabarin, S. A. Effects of microcrystallinity and morphology on physical aging and its associated effects on tensile mechanical and environmental stress cracking properties of poly(ethylene terephthalate). J. Appl. Polym. Sci. 112 (2009) 2906-2917. 

Tohru T, Nobuo O, Koji N, Takashi O (2003) Environmental stress cracking of poly(butylene succinate)/ceUulose triacetate blend films. J Appl Polym Sci 87 510-515 Tomita K, KuraM Y, Nagai K (1999) Isolation of thermophiles degradating poly(L-lactic acid). J Biosci Bioeng 87 752-755... 

El-Hibri MJ. Ternary poly(biphenyl ether sul-fone) resin blends having improved environmental stress cracking resistance. US patent 6 075 100, assigned to BP Amoco Corporation, Chicago, IL 2000. 

LDPE, or its copolymers blended with poly-l-bulene, PB, showed improved processability and resistance to environmental stress cracking... 

Polyethylene, LDPE, or its copolymers when blended with poly-1-butene, PB, showed improved processability and resistance to environmental stress cracking A. Rudin, H. P. Schreiber, French Patent 1,349,823, 17 Jan 1964, Appl. 23 Mar 1962, to Canadian Industries Ltd. 

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