scholarly journals EFFECT OF ETHYLENE OXIDE STERILIZATION ON PLASTISIZER MIGRATION AND MECHANICAL AND BLOOD PROPERTIES OF MEDICAL GRADE POLYVINYLE CHOLORIDE

2022 ◽  
Vol 23 (1) ◽  
pp. 282-293
Author(s):  
Maryam Poostchi ◽  
Hamed Bagheri
Keyword(s):  
Differential Scanning Calorimetry ◽  
Gas Chromatography ◽  
Ethylene Oxide ◽  
Polyvinyl Chloride ◽  
Medical Equipment ◽  
Maximum Level ◽  
Scanning Calorimetry ◽  
Sterilization Process ◽  
Ethylhexyl Phthalate ◽  
Ethylene Oxide Sterilization

The use of phthalates as a plasticizer in plasticized polyvinyl chloride (PVC) always poses the threat of migration of phthalates into the environment through medical equipment. Phthalates can be used with natural-based plasticizers, such as Epoxidized soybean oil (ESBO) known as phthalate’s scavenger and PVC stabilizers. PVC formulations were characterized by different combinations of di (2-ethylhexyl) phthalate (DEHP) 30-40% with 5% ESBO. PVC flexibility increased significantly in the presence of ESBO, without a change in strength (tensile test). The decrease of the Tg temperature by adding ESBO in Differential Scanning Calorimetry indicated that ESBO preserved DEHP in the polymer. Also, it was shown that the sterilization process with Ethylene Oxide, similar to ESBO, decreased the Tg of polymer. DEHP migration was evaluated at a maximum level to the environment using the Gas Chromatography test. Samples containing ESBO showed less hemolysis. ABSTRAK: Penggunaan phthalates sebagai plasticizer dalam plastik polyvinyl chloride (PVC) selalu menimbulkan ancaman penghijrahan phthalates ke alam sekitar melalui peralatan perubatan. Phthalates boleh digunakan dengan plasticizer berasaskan semula jadi, seperti minyak kacang soya Epoxidized (ESBO) yang dikenali sebagai pemulung phthalate dan penstabil PVC. Formulasi PVC dicirikan oleh kombinasi yang berbeza di (2-ethylhexyl) phthalate (DEHP) 30-40% dengan 5% ESBO. Fleksibiliti PVC meningkat dengan ketara di hadapan ESBO, tanpa perubahan kekuatan (ujian tegangan). Penurunan suhu Tg dengan menambahkan ESBO dalam Calorimetri Pengimbasan Berbeza menunjukkan bahawa ESBO mengekalkan DEHP dalam polimer. Juga, ditunjukkan bahawa proses pensterilan dengan Etilena Oksida, serupa dengan ESBO, menurunkan Tg polimer. Penghijrahan DEHP dinilai pada tahap maksimum ke lingkungan menggunakan uji Kromatografi Gas. Sampel yang mengandungi ESBO menunjukkan kurang hemolisis. 

scholarly journals Films Based on a Blend of PVC with Copolymer of 3-Hydroxybutyrate with 3-Hydroxyhexanoate

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 270
Author(s):  
Evgeniy V. Belukhichev ◽  
Vera E. Sitnikova ◽  
Evgenia O. Samuylova ◽  
Mayya V. Uspenskaya ◽  
Daria M. Martynova
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Environmental Pollution ◽  
Polyvinyl Chloride ◽  
Polymer Films ◽  
Thermomechanical Analysis ◽  
Packaging Materials ◽  
Packaging Film ◽  
Scanning Calorimetry ◽  
Environmental Friendliness

Polymeric packaging materials are one of the factors of environmental pollution. Reducing the environmental burden is possible by increasing the environmental friendliness of packaging materials. In this work, we study polymer films based on polyvinyl chloride (PVC) with a copolymer of 3-hydroxybutyrate with 3-hydroxyhexanoate P (3-GB) (3-GG) with different component ratios. The process of processing blends in the process of obtaining a packaging film is considered. The optical characteristics of the obtained films are determined. Thermal analysis of the obtained films was carried out using the differential scanning calorimetry (DSC), TGA, and thermomechanical analysis (TMA) methods. The degree of gelling of the resulting mixture was determined. It is shown that PHB has miscibility with PVC.

Molar absorptivities of beta-NADH and beta-NADPH.

1976 ◽  
Vol 22 (2) ◽  
pp. 151-160 ◽  
Author(s):  
J Ziegenhorn ◽  
M Senn ◽  
T Bücher
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Gas Chromatography ◽  
Resonance Spectroscopy ◽  
Gas Liquid Chromatography ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
Moisture Analysis ◽  
Increasing Temperature

Abstract Re-investigating the accuracy of the commonly used values for molar absorptivities (epsilon) of beta-NADH and beta-NADPH at Hg 334, Hg 365, or 340 nm, we obtained the following results: The maximum of absorbance of NADH is shifted from about 340 nm at 0 degrees C to about 338.5 nm at 38 degrees C; the corresponding maxima of NADPH are located at about 0.5-nm longer wavelengths. In addition, the absorption curves of both coenzymes broaden with increasing temperature. For these reasons, the epsilon-values of NADH and NADPH are generally different from each other, and are temperature-dependent. Only at 334 nm are they almost identical and nearly independent of temperature. Therefore this wavelength is recommended for precise measurements. The epsilon-values of these coenzymes are influenced by ionic strength and pH. To determine the absolute values of the molar absorptivities, we performed the glutamate dehydrogenase or lactate dehydrogenase assay with carefully purified 2-oxoglutaric acid or pyruvic acid in the presence of excess coenzyme. The purity of the substrates was checked through differential scanning calorimetry, moisture analysis, gas-liquid chromatography, gas chromatography in combination with mass spectrometry, and nuclear magnetic resonance spectroscopy. The epsilon-values observed under the various conditions are about 1-7% higher than those currently used.

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