Influence of moisture on the time and temperature dependent properties of polymer systems

Walter, H.; Dermitzaki, E.; Shirangi, Hossein; Wunderle, Bernhard; Hartmann, Stefan; Michel, B.

doi:10.1109/esime.2009.4938469

Cited by 12 publications

(2 citation statements)

References 7 publications

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“…Since moisture can affect both physical and chemical properties of polymers, PHB and PLLA were placed in a vacuum desiccator at ambient temperature to remove the moisture inside . After 24 h, these dried polymers were dissolved in a suitable solvent: chloroform with a weight ratio of 50:50.…”

Section: Methodsmentioning

confidence: 99%

Simultaneous Visualization of Phase Separation and Crystallization in PHB/PLLA Blends with In Situ ATR-FTIR Spectroscopic Imaging

Kazarian

Sato

2020

Macromolecules

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The detection of phase separation and crystallization in biopolymer blends is an important aspect of biopolymer processing. In this study, attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopic imaging has been applied to visualize the crystallization and phase separation of a poly(3-hydroxybutyrate) (PHB)/poly(l-lactic acid) (PLLA) blend simultaneously in situ. The peak shift of the ν(CO) band of PHB during the isothermal crystallization process revealed a transformation of the intermolecular interaction between PHB and PLLA in the miscible state to the inter- and intramolecular interactions between PHBs in the immiscible state. The appearance and gradual separation of crystalline PHB-rich domains and crystalline PLLA-rich domains in the acquired ATR-FTIR spectroscopic images clearly showed the whole dynamic process of phase separation. With increasing isothermal crystallization time, the larger size of crystalline polymer-rich domains and the increasing integrated absorbance of the ν(CO) band of crystalline polymers both revealed the increasing degree of crystallization in the polymer blend, which is constant with the isothermal crystallization process of pure polymers. The extent of phase separation between crystalline PHB-rich domains and crystalline PLLA-rich domains is enhanced with increasing isothermal crystallization temperature. This is because the higher isothermal crystallization temperature slows down the crystallization, which leaves more time for phase separation. The degree of crystallization in the blend decreased with increasing isothermal crystallization temperature, which was also constant with the isothermal crystallization process of the pure polymers. Finally, a new proposal for the mechanism of phase separation and crystallization in the polymer blend has been discussed. It was found that decreasing the isothermal crystallization temperature is an effective method to restrict the phase separation and control the final morphology in the upper critical solution temperature (UCST) crystallizable polymer blend.

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Section: Methodsmentioning

confidence: 99%

Simultaneous Visualization of Phase Separation and Crystallization in PHB/PLLA Blends with In Situ ATR-FTIR Spectroscopic Imaging

Kazarian

Sato

2020

Macromolecules

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“…In contrast, at application temperatures as high as 125°C or 150°C the material relaxes quickly in the order of hours or seconds, respectively. (Linz, 2011) ms sec h d m a 10 (Linz, 2011) The influence of the humidity could be determined as described by Walter et al (2009). Yet, the effort was not made as the data on the dry condition was considered sufficient.…”

Section: Relaxation Behaviormentioning

confidence: 99%

Contacting electronics to fabric circuits with nonconductive adhesive bonding

Linz

Krshiwoblozki

Walter

et al. 2012

Journal of The Textile Institute

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For over two decades different types of fabric circuits have been developed. These are fabrics with integrated electric conductors. However, a technology for contacting electronics to these circuits in a simple and reliable manner was missing. This inhibited any greater commercial success of fabric circuits as potential means to create electronics in textiles applications. This publication presents a novel contacting approach based on non conductive adhesive bonding that is both simple and very versatile concerning the choice of fabric circuit and type of electronics to be contacted. Test vehicles with two different kinds of fabric circuits were developed and exposed to different kinds of textile typical stress. The results show that this contacting approach is very reliable. Finally, two demonstrators were developed, to show the potential of this novel process

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