Poly (neopentylene carbonate) hyperstars

• Branched aliphatic polycarbonates were synthesized by ring opening polymerization of 5,5-dimethyl-1,2-dioxane-2-one (NPC) initiated from polyfunctional alcohols and a commercial hyperbranched polyester (BOLTORN(R)). Polymerizations in the presence of fumaric acid under bulk conditions allowed high conversion (80%) without gelation. The synthesis of polymers with long chain branches was confirmed by size exclusion chromatography and universal calibration. The Mark-Houwink exponent decreased, indicating an increased density, while increasing the number of arms. The star polymers with up to four arms showed thermal properties T-g (20-30degreesC) and T-m (100-110degreesC) similar to linear PNPC.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik -- Polymerteknologi (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering -- Polymer Technologies (hsv//eng)

Nyckelord

cationic polymerization

chromatography

crystallization

hyperbranched

polycarbonates

cationic polymerization

aliphatic polyesters

cyclic carbonates

block-copolymers

behavior

acid

polylactones

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)