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Improving glass transition temperature of unsaturated polyester thermosets: Conventional unsaturated polyester resins
Author(s) -
Stuck Moritz,
Krenz Irina,
Schulze Kökelsum Benedikt,
Boye Susanne,
Voit Brigitte,
Lorenz Reinhard
Publication year - 2021
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49825
Subject(s) - thermosetting polymer , styrene , glass transition , curing (chemistry) , materials science , unsaturated polyester , maleic anhydride , polyester , alkyd , composite material , polymer chemistry , copolymer , polymer , coating
Highly crosslinkable unsaturated polyester resins (UPR) have attracted many interests in the application as reinforced matrix materials. Here, we present a systematical study of the influence of different curing conditions and styrene concentrations on resin viscosity and dynamic‐mechanical properties of the thermoset. The pure maleic Palapreg® P18‐03 was selected as model UPR because of its broad industrial use. By applying newly developed thermal curing profiles (without thermal initiators) and by raising the styrene content, the T g of the network could be increased up to 206/215°C (1/10 Hz). For the first time, a fast curable UPR based on propylene glycol and neopentyl glycol with a T g of up to 215°C is described. A partial substitution of problematic styrene with methylmethacrylate, tert ‐butylacrylate, and maleic anhydride (MA) was studied as well. MA leads to significantly improved resin reactivity. A resin containing 42 wt% styrene and 8 wt% MA yields thermosets with remarkably improved mechanical properties and with a narrower glass transition range compared to the original P18‐03.