Ring-opening polymerisation properties

Characteristic of these models of active sites is the appearance of the OZn O Zn(0)Et species. Considering the structural properties of the discussed catalysts as well as the polymer chain microstructure and the structure of the end groups of poly(propylene oxide) obtained with the PhOZnOCeHi ( -Bu)OZnEt catalyst, a concerted mechanism of epoxide ring-opening polymerisation with catalysts containing multinuclear species, including those with condensed zinc atoms, has been postulated [65,74] ... 

Polyester polyols for rigid PU foams can be obtained by ring opening polymerisation of s-caprolactone, initiated by various polyols such as a-methyl glucoside, sorbitol, pentaerythritol or trimethylolpropane. A polyester polyol derived from penteaerythritol has the following properties functionality of 4 OH groups/mol, hydroxyl number of 600 mg KOH/g, acid number of around 2 mg KOH/g and a of viscosity 7,000 mPa-s, at 25 °C (reaction 16.8) [2, 33-35]. 

Various biodegradable polycarbonate(s) (PC) polymers have been fabricated via the organocatalytic ring-opening polymerisation of functional cyclic carbonate monomers, which were quarternised to create cationic polymers with various pendent structures such as alkyl, aromatic and imidazolinium (Figure 8.4). These polymers have shown excellent antimicrobial properties and haemolytic characteristics when assayed using rat red blood cells [98]. 

Table 4.2 Properties of poly(trimethylene carbonate) of different molar masses obtained via ring-opening polymerisation...

Copolymerisation, which is often carried out in order to gain a better insight into the nature of polymerisation initiating and/or propagating species and to modify the properties of the polymeric products formed, has also been satisfactorily carried out in the case of cycloolefins. The ring-opening metathesis... 

Norbornenyl functionalised linseed oil and cyclopentadiene oligomer-based thermosetting resins have been successfully synthesised using dicy-clopentadiene or other polycyclic norbornene-based comonomers as cross-linkers. New biorenewable-based thermosets have been successfully synthesised by the ring opening metathesis polymerisation of norbornenyl functionalised fatty alcohols of soybean and castor oils. The castor oil-based thermoset exhibits lower soluble fractions and higher thermal stability and mechanical properties compared with the soybean oil-based thermoset. This is due to more effective cross-linking. ... 

---