Polyester polyols acid number

Synthesis MDI prepolymer with 1000 MW polyester polyol, NCO/OH = 2.0, chain-extended with 1,4-butandiol, acid number of polyester 0.6. 

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]. 

Acid number is of concern with both polyether and polyester polyols, since acidity affects the kinetics of the urethane reaction. Determination is by po-tentiometric titration. 

BaycoU AS 1160 is a highly branched polyester polyol (PL) consisting of four different constituents (see Fig. 10.2). The material typically has a low acid number, and a majority of end groups are hydroxyl that can react with a phenyl-based isocyanate to produce a polyurethane adhesive. Specification Umits require the water... 

Table 11.2 gives a survey about major use areas for adhesives based on renewable sources. The share of renewable raw materials in the sealants market is well below 5%. Numbers in Table 11.2 do not include polyurethanes containing oleochemical-based polyols, vegetable oil-based polyesters and polyamides based on dimer fatty acids in total estimated at 35 mto in 2006, 42 mto in 2010. Projection into 2010 shows that without disruptive innovations the share of natural-based adhesives will further decline to a mere 15% in total. 

A substantial number of studies on the characterization of vehicle paints, mainly alkyd and acrylic resins, have been reported. Alkyd resins, which are complex polyesters formed by co-polymerizing phthalic anhydride, polyols, and saturated and rm-saturated fatty acids, can usually be classified with MS techniques on the basis of hydrocarbon chain length and modification components such as melamine. Characterizations of acrylic resins are based on Cl MS analysis of monomers that are reasonably reproducible by pyrolysis techniques. 

Soybean oil is an abundant annually renewable resource. It is composed of triglycerides with long chain saturated and unsaturated hitty acids. The presence of these unsaturated tty acids results in poor oxidative stability. However, this enhanced reactivity also allows for chemical modification to introduce new functionalities to the oil. A novel single-step catalytic ozonolysis and in-situ reaction will be described. The reaction proceeds rapidly and efficiently at room temperature in the absence of solvents. The catalytic ozonolysis reaction has been used to reduce the unsaturation in soybean oil, and successfiiliy prepare a number of potentially useful materials such as bio-lubricants with good thermal/oxidative stability, bio-diesel with thermal properties comparable to that of Diesel Fuel 2, and bio-plastic intermediates such as polyols, polyesters, and polyamides. This new class of soy-based materials is competitive both in cost and performance to petroleum based nuterials and offers the added advantage of being environmentally friendly and sustainable. 

---