Environmentally Friendly Plasticizers for PVC: Improved Material Properties and Long-term Performance Through Plasticizer Design
2007 (English)Doctoral thesis, comprehensive summary (Other scientific)
Linear and branched poly(butylene adipate) polyesters with number-average molecular weights ranging from 700 to 10 000 g/mol, and degrees of branching ranging from very low to hyperbranched were solution cast with PVC to study the effects of chemical structure, molecular weight, end-group functionality, and chain architecture on plasticizing efficiency and durability. Miscibility was evaluated by the existence of a single glass transition temperature and a shift of the carbonyl group absorption band. Desirable mechanical properties were achieved in flexible PVC films containing 40 weight-% of polyester plasticizer. Methyl-ester-terminated polyesters with a low degree of branching and an intermediate molecular weight enhanced the plasticizing efficiency, as shown by greater elongation, good miscibility, and reduced surface segregation. A solid-phase extraction method was developed to extract the low molecular weight products that migrated from pure poly(butylene adipate) and PVC/ poly(butylene adipate) films during aging in water. The effects of branching, molecular weight, end-group functionality, and polydispersity on plasticizer permanence were evaluated by quantification of low molecular weight hydrolysis products, weight loss, surface segregation, and the preservation of material properties during aging. A more migration-resistant polymeric plasticizer was obtained by combining a low degree of branching, hydrolysis-protecting end-groups, and higher molecular weight of the polyester. Films plasticized with a slightly branched polyester showed the best durability and preservation of material and mechanical properties during aging. A high degree of branching resulted in partial miscibility with PVC, poor mechanical properties, and low migration resistance. The thermal stability of polyester-plasticized films was higher than that of films containing a low molecular weight plasticizer, and the stabilizing effect increased with increasing plasticizer concentration.
Place, publisher, year, edition, pages
Stockholm: KTH , 2007. , 66 p.
Trita-FPT-Report, ISSN 1652-2443 ; 2006:45
poly(butylene adipate), poly(vinyl chloride), plasticizers, miscibility, mechanical properties, surface segregation, migration, degradation products
IdentifiersURN: urn:nbn:se:kth:diva-4272ISBN: 978-91-7178-557-2OAI: oai:DiVA.org:kth-4272DiVA: diva2:11561
2007-02-16, Sal F3, KTH, Lindstedtsvägen 26, Stockholm, 10:00
Södergård, Anders, Professor
QC 201008052007-02-142007-02-142010-08-05Bibliographically approved
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