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importance of glass transition temperature

This would provide a polymer system that remains flexible and rubbery throughout the entire operating temperature range of the device. Methods: This challenge has been addressed successfully in the industry by one of two ways. Get in touch with our experts aboutyour processing issues and needs! 1994 Apr;12(4):114-7. doi: 10.1016/0167-7799(94)90087-6. HHS As a result, this low stress polymer will not damage delicate components during thermal cycling. 1995 Mar 31;267(5206):1924-35 J Pharm Sci. 2009 Sep;98(9):2935-53. doi: 10.1002/jps.21728. iGC SEA can provide a fast and accurate determination of this property as well as its dependence on relative humidity. Components in an electronic assembly may be pressure sensitive or delicate in nature and they may have CTE’s much lower than 30 ppm. J Pharm Sci. Epub 2006 Sep 2. Please enable it to take advantage of the complete set of features! National Center for Biotechnology Information, Unable to load your collection due to an error, Unable to load your delegates due to an error. 13. 2019 Dec 23;37(1):11. doi: 10.1007/s11095-019-2739-8. 2011 Oct;100(10):4471-81. doi: 10.1002/jps.22634. Int J Pharm. 2006 Oct;23(10):2239-53. doi: 10.1007/s11095-006-9052-z. Epub 2011 May 23. This paper describes the characterisation of Epub 2005 Aug 3. This site needs JavaScript to work properly. Get the latest public health information from CDC: https://www.coronavirus.gov. USA.gov. 1990 Jun;7(6):654-7 Epub 2013 Apr 2. National Center for Biotechnology Information, Unable to load your collection due to an error, Unable to load your delegates due to an error. Freeze drying of nanosuspensions, 2: the role of the critical formulation temperature on stability of drug nanosuspensions and its practical implication on process design. Breen ED, Curley JG, Overcashier DE, Hsu CC, Shire SJ. Due to these thermal changes, a polymers T(g) (glass transition temperature) and CTE (co-efficient of thermal expansion) should be factored into the decision tree when selecting an appropriate polymer system. Importance of glass transition temperature in accelerated stability testing of amorphous solids: case study using a lyophilized aspirin formulation. Find NCBI SARS-CoV-2 literature, sequence, and clinical content: https://www.ncbi.nlm.nih.gov/sars-cov-2/.  |  eCollection 2019 Dec. Snell JR, Kumar NSK, Suryanarayanan R, Randolph TW. The goal is to provide a system that closely mirrors the dimensional changes of the components in the assembly during a thermal cycle. This approach too, has found industry success in the bonding and potting of electrical/electronic assemblies. As with melting though, the Tg is signified by a change in heat capacity. A typical filled epoxy system may have a CTE in the range of 30-60 ppm below its T(g) and a CTE in the range of 120-180 ppm above its T(g). USA.gov. NIH Cast Electrical and Mechanical Components, Maintenance, Restoration and Repair Materials. Physical Stability of Amorphous Solid Dispersions: a Physicochemical Perspective with Thermodynamic, Kinetic and Environmental Aspects. Conclusions: The glass transition temperature is lower than the melting point of its crystalline form, if it has one. Nanobubbles in Reconstituted Lyophilized Formulations: Interaction With Proteins and Mechanism of Formation. Significance of local mobility in aggregation of beta-galactosidase lyophilized with trehalose, sucrose or stachyose. Glass transition temperatures were measured using DSC and dielectric relaxation spectroscopy. An approach that has been successfully implemented in many industry applications. Sucrose formulation (Tg approximately 59 degrees C) when stored at 60 degrees C was found to undergo significant aggregation, while the trehalose formulation (Tg approximately 80 degrees C) was stable at 60 degrees C. The instability observed with sucrose formulation at 60 degrees C can be attributed to its Tg (approximately 59 degrees C) being close to the testing temperature. In the end, this damage may compromise the hermetic seal and or affect the reliability of the device. -, Pharm Res. Pharm Res. 1995 Jun;12(6):799-806 In operation, these assemblies will experience some form of thermal cycling, whether it be through heat generation, or through an environmental temperature change. 1997 May;14(5):596-600. doi: 10.1023/a:1012196826905. Beirowski J, Inghelbrecht S, Arien A, Gieseler H. J Pharm Sci. NLM Increase in the protein/sugar ratio was found to increase the Tgs of the formulations containing sucrose or trehalose, but to different degrees. 2001 Sep;18(9):1345-53. doi: 10.1023/a:1013054431517. Each polymer with an amorphous structure has its own unique glass transition temperature, which makes a given polymer … Accelerated stability testing of bioproducts: attractions and pitfalls. Lin X, Hu Y, Liu L, Su L, Li N, Yu J, Tang B, Yang Z. Pharm Res. Purpose: 2018 Apr 23;35(6):125. doi: 10.1007/s11095-018-2408-3. Why is it important to know these physical properties when selecting a polymer for potting or bonding electronic assemblies? Clipboard, Search History, and several other advanced features are temporarily unavailable. The relevance of the amorphous state to pharmaceutical dosage forms: glassy drugs and freeze dried systems. 2017 Oct 3;13(10):2364-2378. doi: 10.1080/21645515.2017.1356952. In demanding electrical/electronic applications, thermosetting epoxies and polyurethanes may be used to bond components or hermetically seal the assemblies through a potting or casting process. Int J Pharm. In Electronic and Electrical assemblies, why is the Glass Transition Temperature and CTE important when selecting a Polyurethane or Epoxy System? A marked change in CTE also takes place at this transition temperature. An example of this would be an epoxy system with a high loading of inorganic filler. 2019 Jul 8;1:100022. doi: 10.1016/j.ijpx.2019.100022. Local mobility in amorphous pharmaceuticals--characterization and implications on stability. The purpose of this study is to highlight the importance of knowing the glass transition temperature, Tg, of a lyophilized amorphous solid composed primarily of a sugar and a protein in the interpretation of accelerated stability data. NLM A glass transition temperature (Tg) is the temperature at which a polymer turns from a ductile material to a hard, brittle material. Int J Pharm X. COVID-19 is an emerging, rapidly evolving situation. Results: Shmool TA, Woodhams PJ, Leutzsch M, Stephens AD, Gaimann MU, Mantle MD, Kaminski Schierle GS, van der Walle CF, Zeitler JA. 1. J Pharm Sci. This damage may show up as stress cracks in or around components, or a loss of adhesion between components. 2005 Aug;22(8):1358-64. doi: 10.1007/s11095-005-5262-z. Importance of Glass Transition Temperature [2]:- The glass transition temperature is an important property for a polymer. Please enable it to take advantage of the complete set of features! 1996 Mar;85(3):345-7 This helps minimize the development of any stresses within the assembly. 1996 Mar;85(3):345-7. Find NCBI SARS-CoV-2 literature, sequence, and clinical content: https://www.ncbi.nlm.nih.gov/sars-cov-2/. 1999 Mar 15;179(2):179-207. doi: 10.1016/s0378-5173(98)00338-x. 2013 Apr;102(4):1139-54. doi: 10.1002/jps.23440. In demanding electrical/electronic applications, thermosetting epoxies and polyurethanes may be used to bond components or hermetically seal the assemblies through a potting or casting process. In demanding electrical/electronic applications, thermosetting epoxies and polyurethanes may be used to bond components or hermetically seal the assemblies through a potting or casting process. Phone: (+1) 905.673.0510Toll free North America: 1.800.563.37696380 Viscount Road, Mississauga, ON L4V 1H3. The glass transition temperature (Tg) value can be measured from the plot by calculating the temperature where the heat flow rate is exactly at the middle of pre- and post-transition rates. Trends Biotechnol. -, J Pharm Sci. -. The first is to provide a polymer system with a high T(g) and low CTE. Effect of water on the chemical stability of amorphous pharmaceuticals: I. Canada. 2007 Sep;24(9):1660-7. doi: 10.1007/s11095-007-9296-2. Since the formulations exist in glassy state during their shelf-life, accelerated stability data generated in the glassy state (40 degrees C) is perhaps a better predictor of the relative stability of formulations than the data generated at a higher temperature (60 degrees C) where one formulation is in the glassy state while the other is near or above its Tg. 2020 Jan;109(1):284-292. doi: 10.1016/j.xphs.2019.05.005. Usefulness of the Kohlrausch-Williams-Watts stretched exponential function to describe protein aggregation in lyophilized formulations and the temperature dependence near the glass transition temperature. 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