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Włóknotwórcze poliestry o podwyższonej termostabilności

Dutkiewicz S., Grochowska-Łapienis D., Twarowska-Schmidt K.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2003

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Vol. 52, nr 25

409-410

EN

The synthesis of thermoresistant and flame - retardant modified polyesters arouse interest in many research centers world - wide. The results of research are liquid crystalline polyesters characterized by high strength, having oxygen index (OI) higher than 30 and high melting temperature. Thermoresistance of polymers along with lowered flammability can be obtained by introducting aromatic fragments to their structure [2,4]. Poly(ethylene therephthalate) (PET) has moderate flammability, good thermostability heat resistance, and mechanical strength. Poly(ethylene naphthalene-2,5-dicarboxylate) has better thermostability and mechanical strength than PET [1,3]. It has been expected that some properties of copolymers of DMT/DMN with high content of one comonomer will be close to the properties of the corresponding homopolymer. The aim of work was to obtain copolyesters with better thermostability in comparison with PET. Therefore copolymers of dimethyl therephalate (DMT) with dimethyl 2,6-naphthalenedicarboxylate (DMN) and ethylene glycol were synthezed and their thermal properties were studied. For some polymers glass transition and melting temperatures were determined. The TGA method and OI were used to determine the thermostability and flame resistance. Fibres obtained from these copolyesters have better thermostability than fibres obtained from PET.

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Synthesis of Poly(L(+) Lactic Acid) by Polycondensation Method in Solution

Dutkiewicz S., Grochowska-Łapienis D., Tomaszewski W.

Fibres & Textiles in Eastern Europe

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2003

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Vol. 11, no. 4 (43)

66--70

EN

In this work. the results of the synthesis of high molar weight poly(L(+) lactic acid) (PLA) which is able to thermally crystallise have been described. Such PLA can be used in fibre formation. The synthesis of poly(L(+) lactic acid) was carried out in a solution of o-dichlorobenzene, p-xylene, o-chlorotoluene, and diphenyl ether. As a monomer, L(+)lactic acid purified by distillation was applied. Stannous chloride and metallic tin were used as catalysts in a quantity of 1.0 wt% calculated on the monomer. Polycondensation was carried out over a period from ten to over 20 hours. The resulting poly(L(+) lactic acids) were characterised by DSC, and the molar masses were measured by the GPC method. Their melting points, thermostabilities, inherent viscosities, and flow indexes were also determined. The poly(L(+) lactic acid) with the highest molar mass was obtained in the synthesis carried out in diphenyl ether under vacuum.

PL

W pracy przedstawiono wzniki badań, których celem było uzyskanie polifkwasu L(+) mlekowego) (PLA), charakteryzującego się zdolnością do krystalizacji termicznej i wysokim ciężarem cząsteczkowym. Cechy te sprzyjają wykorzystaniu PLA do formowania włókien. Syntezą PLA prowadzono w roztworze o-dichlorobenzenu, p-ksylenu, o-chlorotoluenu i eteru difenylowego. Jako monomer zastosowano kwas L(+) mlekowy oczyszczany przez destylację. Katalizatorami procesu były: chlorek cynowy i cyna metaliczna, stosowane w stężeniu 1,0% w przeliczeniu na monomer. Czas procesu polikondensacji wynosił od kilkunastu do kilkudziesięciu godzin. Dokonano oceny wybranych właściwości fizyko-chemicznych otrzymanego PLA. PLA o najlepszych właściwościach otrzymano w wyniku syntezy prowadzonej w eterze difenylowym.

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Polyesters with Enhanced Heat Resistance. Plastics and Fibres

Dutkiewicz S., Grochowska-Łapienis D., Boryniec S., Twarowska-Schmidt K.

Fibres & Textiles in Eastern Europe

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2003

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Vol. 11, no. 2 (41)

28--31

EN

Dimethyl terephthalate (DMT) and dimethyl 2,6-naphthalate (DMN) copolymers with ethylene glycol (EG) were obtained by the melt polycondensation method. Melt points and glass transition temperatures were determined for selected copolymers using DSC. The evaluation of their thermal stability was based on TGA results. Changes in relative viscosities and the lowering of the mass of the polymer samples after long-lasting heating at 200°C as well as changes in the melt viscosity after 1 h of heating at 290°C were also investigated. Fire resistance was evaluated on the basis of the oxygen index (OI) tests. The mechanical properties and thermal stability of fibres obtained from DMT/DMN copolyesters were also determined.

PL

Metodą polikondensacji w stopie otrzymano kopolimery dimetylotereftalanu (DMT) i 2,6-dimetylonaftalanu (DMN) z udziałem glikolu etylenowego. Dla wybranych kopolimerów oznaczono temperatury topnienia i zeszklenia metodą DSC oraz termostabilność metodą TGA. Zbadano zmiany lepkości względnej i masy polimerów po długotrwałym wygrzewaniu w temperaturze ponad 200°C oraz zmiany lepkości stopowej polimerów po wygrzewaniu w temperaturze 290°C w czasie 60 min. Odporność na palenie określono, wyznaczając indeks tlenowy Ol. Z kopoliestrów DMN/DMT wytworzono włókna. Oceniono właściwości mechaniczne oraz termostabilność włókien.