Sequence length of ethylene oxide and the amount of end groups in polyacetal copolymers were determined using proton NMR. Peaks from ethylene oxide usually appear in the region from 3.5 to 3.8 ppm, when tetramethylsilane was used as the internal standard. These peaks were divided into three triad se
Degradation and stabilization of polyacetal copolymers
β Scribed by F. M. Berardinelli; T. J. Dolce; Cheves Walling
- Publisher
- John Wiley and Sons
- Year
- 1965
- Tongue
- English
- Weight
- 616 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
β¦ Synopsis
Acetal copolymers prepared from trioxane and ethylene oxide consist of polyoxymethylene segments with oxyethylene units distributed in the chain. These oxyethylene units profoundly affect the thermal and chemical behavior of the polymer. The presence of the oxyethylene units renders the copolymer amenable to thermal or base hydrolytic treatment which results in a final product with stable endgroups. The copolymers so obtained are significantly more stable, thermally and chemically, than acetylated polyoxymethylene homopolymer.
Zusammenfassung
Aus Trioxan und Athylenoxyd dargestellte Acetalcopolymere bestehen aus Polyoxymethylensegmenten mit uber die Kette verteilten Oxyathyleneinheiten. Diese Oxyathyleneinheiten besitzen einen tiefgreifenden Einfluss auf das thermische und chemische Verhalten des Polymeren. Die Anwesenheit der Oxyathyleneinheiten macht das Copolymere einer thermischen oder basischen hydrolytischen Behandlung zuganglich, welche zu einem Endprodukt mit stabilen Endgruppen fuhrt. Die so erhaltenen Copolymeren besitzen eine hahere thermische und chemische Stabilitat als das acetylierts Polyoxymethylenhomopolymere.
π SIMILAR VOLUMES
Polycyanoacrylates were found to be inherently unstable. Even in the absence of a deliberately added strong base, their molecular weights decreased drastically on standing in solution in accord with observations by Ryan and McCann (Makromol Chem Rapid Commun 1996, 17, 217). The initial high molecula
## Abstract Polymer blends of poly(propylene) (PP) and polyacetal (polyoxymethylene, POM) with ethylene vinyl alcohol (EVOH) copolymers were investigated by differential scanning calorimetry (DSC), rheological, tensile, and impact measurements, Fourier transform infrared spectroscopy (FTIR), and sc