Creep recovery of acrylate urethane oligomer/acrylate networks. 2. Investigation of different modes of molecular motion

✍ Scribed by K. Kawate

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 222 KB
• Volume: 35
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(19971115)35:15<2543::aid-polb16>3.0.co;2-5

✦ Synopsis

The creep recovery and dynamic mechanical properties of acrylate urethane oligomer/acrylate networks were investigated. The retardation spectra L CR obtained from the creep recovery experiments were significantly different from the corresponding retardation spectra L DMA obtained from the dynamic mechanical measurements. The reduced frequency v* dependence of L DMA and the relaxation spectra H DMA in the higher v* region were approximately represented as L DMA ϰv* 0 p and H DMA ϰv *q , although L CR decreased faster than L DMA with an increase in v*. The exponents q were close to 1 2 characterizing the Rouse modes in the systems containing an acrylate urethane oligomer of M w Å 5000 but less than 1 2 in the system containing an acrylate urethane oligomer of M w Å 12,000. For the latter systems, significant thermorheological complexity was observed.