Processable poly(cycloacetals) with high molar masses (M-n) up to 38 kDa were synthesized in a systematic manner. Di-trimethylolpropane (Di-TMP) was used as tetravalent alcohol and was combined with a series of available dialdehydes, after a model reactivity study. These polymers have a high thermal stability with degradation temperatures (T-d) up to 370 degrees C while the glass transition temperatures (T-g) ranged from room temperature to 115 degrees C. Trends in T-g modulation were confirmed by a theoretical simulation. Moreover, the poly(cycloacetals) showed favourable mechanical and optical properties. (C) 2016 Elsevier Ltd. All rights reserved.