Low Melting Temperature Glasses

Low melting temperature phases (glasses) have long been considered as flame-retardant polymer additives. Low melting temperature glasses can improve the thermal stability and flame retardance of polymers by 

The action of ammonium pentaborate (APB) in polyamide-6 as glass former has been studied. The degradation of APB into boric acid and boron oxide provides a low melting glass at temperatures of interest and then the char formed by the degradation of polyamide-6 is protected by the glass that induces the fire-retardant 

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Fire Retardants with emphasis on metal hydroxides but also inclusion of antimony oxide, ammonium polyphosphate, borate salts and low melting temperature glasses. Chapter 17. 

L. AField and R.S.Muller, Fusing silicon wafers with low melting temperature glass. Sensors actuators, A21-23,(1990), 935-938... 

Other uses of Snp2 are in the synthesis of fluorophosphate glasses having low melting temperatures (13—15), in formation of transparent film (16), and in the preparation of optically active alcohols (17). 

Alkyl-aryl substituted PPX is soluble at ambient temperatures and has a comparatively low melting temperature. The glass transition temperatures of alkylphenyl substituted PPX is shown in Table 2.2. 

Polyesters with molar masses of a few thousand are obtained by poly-condensing ethylene glycol with adipic or sebacic acid. The polymers have low glass transition temperatures, because of the flexible ester groups, as well as low melting temperatures, and so are used as flexible segments for elastic fibers, as secondary plasticizers, as nonfatty ointment or cream bases, as well as making leather impermeable because of its water-repellent action. 

As we will see in the next section, a relative low melting temperature is indeed favourable for glass formation. Since the Nagel and Tauc model has mainly been used to describe the stability of amorphous alloys we will treat this model in more detail in section 4. 

All of them exhibit a high solubility in water and a low melting temperature. In addition to their crystalline forms, alkali silicates may also exist in the form of alkali silicate glasses with variable Si02/alkali oxide ratios, which may be produced by a rapid cooling of the pertinent melts. The term water glass desigrrates concentrated solutions of alkali... 

There are several groupings of polymers that are of particular interest. Polymers commonly considered to be elastomers at ambient temperature must have low glass temperatures and be either noncrystalline or, if crystallizable, have low melting temperatures. Some typical polymers in this category are poly(l,4-cis-iso-prene), natural rubber, poly(isobutylene), poly(dimethyl siloxane), and poly(l,4-cis-butadiene). Their melting temperatures are 35 °C, 5 °C,(61) —38 °C and 0 °C respectively. Poly(l,4-cis-isoprene), poly(l,4-cis-polybutadiene) and poly(dimethyl siloxane) are all characterized by low values of A Hu. We can assume that... 

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