The hydrolysis of polyester-ether homologs by an alkali.

Yamamoto, Yoshitake; Sangen, Osamu; Nakano, Hirofumi

doi:10.2115/fiber.40.3_t122

Cited by 3 publications

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“…The reason for the increased weight loss (%) due to highest applied stress is unknown. However, one suggestion is that the weight loss of the polyesters is related to the surface area of the fibers 19, 20. We have calculated the increased surface area of the PET1 fibers which was found to be only 2.0%, by taking the extension of 5.0% due to the 2000 g (246 kPa) applied load from the load‐elongation curve.…”

Section: Resultsmentioning

confidence: 99%

Effect of applied stress on the alkaline hydrolysis of poly(ethylene terephthalate) at 40°C: Relevance to medical textiles

Rahman

East

2006

J of Applied Polymer Sci

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Laboratory-accelerated degradation tests have been conducted to understand the stability of high tenacity poly(ethylene terephthalate) (PET) as a result of exposure to stressful chemical environments when used as an implantable prosthesis. The experiments were conducted at 408C to mimic normal physiological conditions. At various time intervals, samples were collected and evaluated for weight loss (%), mechanical properties, and changes in the surface structure. The mechanical properties that were specifically observed include: breaking load, tenacity, breaking strain, work of rupture, and modulus. For all PET fibers loss of work of rupture was the highest. An empirical formula was developed to estimate degradation behavior over time, though such a prediction cannot be verified without further research and observation. The transverse cracks formed on the stressed samples beyond the critical load in an alkaline environment at 408C are similar to those found on the PET prosthetic grafts. The cracks in the experimental samples at 408C and those recovered from human bodies both appear more 'corallite in structures' versus those at room temperature. Therefore, it is concluded that the arterial stress that the PET prosthetic graft encountered inside the human body was higher than the yield load of the fiber.

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Section: Resultsmentioning

confidence: 99%

Effect of applied stress on the alkaline hydrolysis of poly(ethylene terephthalate) at 40°C: Relevance to medical textiles

Rahman

East

2006

J of Applied Polymer Sci

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“…For NaOH, the activation energy was 14.7 AE 1.1 kcal mol À1 , calculated from the data in Table 4. No activation energy was found for aqueous KOH in the literature; however, for aqueous NaOH, the reported activation energy was 17.9 AE 0.3 kcal mol À1 [12], 12.8 and 15.5 kcal mol À1 [27] and 14.7 kcal mol À1 [28].…”

Section: Rahman 385mentioning

confidence: 99%

Relative reactivity of different monovalent alkalis on poly(ethylene terephthalate) geotextiles: Aqueous and alcoholic systems

Rahman

2013

Journal of Industrial Textiles

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The relative rate of degradation of poly(ethylene terephthalate) geotextiles in various monovalent alkali hydroxides was studied in both aqueous and alcoholic systems. In an aqueous system, the reaction of all three alkalis on poly(ethylene terephthalate) geotextiles is restricted to the surface since tenacity loss was insignificant and no surface cracks was noticed, whereas in an alcoholic system, significant loss in tenacity occurred due to the formation of surface crack. Furthermore, the relative rate of reactivity of metal hydroxides in aqueous and alkaline media was temperature dependent. However, in equimolar concentration, at 80 C, the relative rate in an aqueous system is of the following order: LiOH > NaOH > KOH in the ratio of 1.65:1.1:1.0. Above 80 C, the reaction is reversed, as aqueous KOH reacts faster than aqueous NaOH. Two different activation energies were found for aqueous KOH at a threshold temperature of 80 C. Furthermore, in heterogeneous systems using dimethyl terephthalate, aqueous KOH was slightly faster than aqueous NaOH in the temperature range of 70-80 C. In an alcoholic system, KOH is almost 1.5 times faster than NaOH at 20 C and at 60 C.

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Surface area of aqueous sodium hydroxide hydrolyzed high‐speed spun poly(ethylene terephthalate) fibers

Holmes

Zeronian

1995

J of Applied Polymer Sci

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SYNOPSISThe specific surface area (SSA) of delustered undrawn and drawn high-speed spun PET fibers hydrolyzed in aqueous NaOH was measured using three methods: (1) geometric, based on fiber diameter; (2) gas adsorption using N2 and the BET equation; and (3) adsorption of a nonionic surfactant. Increasing the spinning speed had little effect on the SSA of the untreated fibers, while drawing resulted in considerably larger SSA. For the hydrolyzed fibers, both adsorption methods resulted in larger SSAs than that predicted geometrically due to surface pitting. After hydrolysis, the higher spinning speed resulted in a greater increase in SSA over the untreated sample, whereas the increase in SSA was less for the drawn fibers compared to the undrawn. The kinetics of hydrolysis are also discussed. 0 1995 John Wiley & Sons, Inc.

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The hydrolysis of polyester-ether homologs by an alkali.

Cited by 3 publications

References 0 publications

Effect of applied stress on the alkaline hydrolysis of poly(ethylene terephthalate) at 40°C: Relevance to medical textiles

Effect of applied stress on the alkaline hydrolysis of poly(ethylene terephthalate) at 40°C: Relevance to medical textiles

Relative reactivity of different monovalent alkalis on poly(ethylene terephthalate) geotextiles: Aqueous and alcoholic systems

Surface area of aqueous sodium hydroxide hydrolyzed high‐speed spun poly(ethylene terephthalate) fibers

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