Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
Polyester resins range developments
Keywords Baxenden Chemicals, Resins
Baxenden Chemicals Ltd has announced further developments to its pioneering technology for producing a novel range of polyesters. Useful for adhesive applications the Xenol range is used as the polyol component of polyurethane prepolymers and thermoplastic polyurethanes (TPUs).
The patented process uses the condensation polymerisation reaction of, difunctional acids and alcohols to produce hydroxy functional saturated polyesters. This biosynthetic process uses highly efficient enzymes to produce polyester resins with what is thought to be unique properties.
An important feature of this new technique is said to be that polyols with a high molecular weight can be produced. Examples of commercially available hexyleneadipates are Xenol DP9B/1473 and Xenol DP9B/1465 with molecular weights of 8,000 and 10,000 respectively. The materials claim low acid value and a low water content.
According to Baxenden the highly crystalline nature of these polyester materials produces materials which exhibit a more rapid crystal growth at 35°C when compared to conventionally produced material, showing a 3.8 fold increase, as measured using hot stage microscopy.
The company also considers that the process results in polyesters with improved hydrolysis resistance, an important feature in many adhesive applications. Other uses include surface coatings, binders, encapsulants and textile coatings.
Richard Spencer, commercial development manager at Baxenden, comments on the future applications of the technology:
There are many other combinations possible with the large number of difunctional and dihydroxyl reactants available on the market. Not all will be efficiently converted into polymer by the enzyme route. However there is always the possibility of using a wide range of raw materials to design finished products with the desired characteristics for a particular application.
Details available from: Speciality Chemicals Div, Baxenden Chemicals Ltd. Tel: +44 1254 872278; Fax: +44 1254 871247.