摘要:

AbstractThe selection and control of fire retardant polymers for most current applications is made by a prescriptive approach supported by standard tests. There is now much international interest and commitment to new fire safety strategies based on fire safety engineering. This paper outlines some of the issues which need to be addressed over the next decade, if the full benefits of fire retardant polymers are to be recognised in total fire safety designs.

ISSN:0258-0322    

DOI:10.1002/masy.19930740103

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe relationship between flammability and thermal degradation is the consequence of the burning cycle needed to sustain fire. Thermal degradation behaviour of polymers is discussed in relation to generation of fuel and other products, including flame quenchers, and the production of char. The thermal degradation behaviour of the main classes of fire retardant is considered and illustrated by examples of the ways in which specific fire retardants exert their effect on a particular polymer.

ISSN:0258-0322    

DOI:10.1002/masy.19930740104

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractPyrolysis is the important stage of polymer combustion. This process depends on molecular and submolecular structure of polymer as well as conditions of heat affect. It may be realized through the formation of nonvolatile carbonized product. The basic conception of the present work consists in the transformation of macromolecules into carbonized structure which realises by means of formation of the thermodynamically‐advantageous intermediate compounds with a system of π‐conjugated unsaturated carbon bonds (acyclic or aromatic nature) and by their following conversion into condensed aromatic structures.It has been examined the correlation between the structure and properties of carbonized products and the flammability of poly

ISSN:0258-0322    

DOI:10.1002/masy.19930740105

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe distribution of the temperature and the morphology of the charred material formed in the combustion of blends of poly(phenylene ether) (PPE) with high impact polystyrene (HIPS), carried out in the UL94 test, were examined. The effect of the fire retardant triphenyl phosphate is shown to be the decrease of time of burning, of temperature of the specimen and of zone involved in combustion, without apparent modification of the char structure. Hypothesis on gas and condensed phase fire retardant mechanisms are discussed.

ISSN:0258-0322    

DOI:10.1002/masy.19930740106

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractA systematic investigation of structurally identical flame retardant viscose, modal and polyester blended fabrics and fibres was carried out in order to develop a chemical basis for more effective products based on organic and inorganic flame retardants. The oxygen indices and chemical compositions of phosphorus‐nitrogen flame retardants (P‐N) were used in efficiency and synergy evaluations. A new flame retardant viscose fibre containing silicid acid was included in the comparative evaluation procedure. Thermal gravimetry and X‐ray diffractometry were used for determine physical factors during pyrolyzing of fibres. Charred residues were analyzed by applying elementary and solid 13‐C NMR (CPMAS) spectrometry. The pyrolysis gas‐liquid chromatographer connected with a gas phase FT infrared spectrometer was applied to identify the decomposition products of P‐N‐conta

ISSN:0258-0322    

DOI:10.1002/masy.19930740107

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractA method allowing the determination of the formulation leading to the best fire retardancy properties is presented in the case of intumescent systems. The method consists in the determination of invariant physicochemical parameters deduced from TG analysis: invariant activation energy and invariant preexponentiel factor. The relation between the values given by an evaluation test (LOI) and the invariant activation energy is then discussed.

ISSN:0258-0322    

DOI:10.1002/masy.19930740108

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractThe mechanism of intumescence is studied in mixtures of ammonium polyphosphate (APP) with several polycondensates as a part of a systematic study of intumescent fire retardants. It is shown that APP reacts on heating with the polycondensate to form a precursor of the intumescent char which is obtained on further heating. The introduction of the intumescent system in polypropylene does not modify the structure of the char formed on heating. However, the polymer modifies the foaming behaviour of the system. The thermal decomposition of the char occurs with volatilisation of phosphorus moieties and formation of a relatively thermally stable residue. Effects of the thermal behaviour of the char, on fire retardance, are discussed.

ISSN:0258-0322    

DOI:10.1002/masy.19930740109

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractFire retardant intumescent coatings which produce a swollen char on heating are being frequently used to protect buildings containing structural steel from the effects of exposure to high temperatures caused by fire. This paper contains details of a study carried out using thermal analysis techniques to elucidate the mechanisms of the development of intumescent chars during the heating of an intumescent coating system based on ammonium polyphosphate, pentaerythritol and melamine. In particular, the role of melamine as the spumific agent has been studied. The melamine is shown to react chemically with the ammonium polyphosphate in addition to carrying out its role as the spumific, or blowing agent.

ISSN:0258-0322    

DOI:10.1002/masy.19930740110

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractChain fragments with amide and imide groups are the most abundant degradation products of aliphatic polyamides (APA) which derive from scission of the N‐alkylamide bond (‐CH2‐NH‐). In the case of polyamide 6.6 (PA‐6.6), also carbodiimide structures and methyl chain ends are formed, which derive from scission of ‐CH2‐C(=O)‐ bond. Cyclic compounds can be formed besides chain fragments, depending on the type of APA.Ammonium polyphosphate (APP) reacts with APA on heating forming phosphoric esters which decompose giving products similar to those obtained from pure APA. APP increases the yield of carbodiimides from PA‐6.6 which trimerise to triazine structures. The fire retardant mechanism of APP is discussed on the basis of the thermal degradatio

ISSN:0258-0322    

DOI:10.1002/masy.19930740111

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY

摘要:

AbstractIn recent years X‐ray photoelectron spectroscopy (XPS) has rapidly matured and used routinely now in industries / universities providing a wealth of information including elemental composition, chemical bonding and depth profiles of both aspects in the surface of solids. However, few has been reported so far in the flame retardance areas. An attempt has been made in the present paper aiming at introducing and exemplifying examples of XPS applied to the fields relevant to the flame retardance of polymers, such as:degradation of polymers upon heating, synergisms, smoke suppression and structural investigation. All of which were achieved recently in the laborator

ISSN:0258-0322    

DOI:10.1002/masy.19930740112

出版商:Hüthig&Wepf Verlag    

年代:1993

数据来源: WILEY