GPEC

Whereas SEC is the dominant technique for the characterisation of polymers, various nonexclusion liquid chromatographic (NELC) methods, such as GPEC and LACCC offer equally valid possibilities for deformulation of complex polymer systems. In fact, molecular characterisation of polymers in the precip-itation/adsorption mode (gradient HPLC) enables differences in chemical structure and composition to be... 

Table 4.47 Main virtues of GPEC in polymer/additive...

On the whole, GPEC remains a technique in search for polymer/additive applications with real added value [835]. Practical applications of GPEC may be found in the analysis of polymer blends [836], laminates and packaging materials. For example, the technique can be used for determination of the impact modifier content in PS packaging material, which contains a soluble transparent rubber for transparent applications,... 

FMASE Focused microwave-assisted Soxhlet GPEC Gradient polymer elution... 

NP-GPEC Normal-phase gradient polymer detector... 

GPEC 2004 Plastics - Helping Grow A Greener Environment. Proceedings of a conference held Detroit, Mi., 18th-19th Feb.2004. 

J. Biancaniello, L. Headley, M. M. Fisher, and T. Kingsbury, Setting the Record Straight Busting Common Myths about Plastics from Recovered Consumer Electronics, APC-GPEC 2003. 

Proof. Notice that oj gpec r = R, so from / we get a local homomorphism g. To show we have a bijection we may replace X by an affine neighbourhood Spec (A) of x suppose x = [P]. We have a commutative diagram ... 

The chemoenzymatic cascade synthesis of block copolymers combining enzymatic ring opening polymerization (eROP) and atom transfer radical polymerization (ATRP) is reviewed. Factors like reaction condition and initiator structure were investigated and optimized prior to the polymerization. The synthesis of block copolymers was successful in two consecutive steps, i.e. eROP followed by ATRP as evident from SEC and GPEC analysis. While in the one-pot approach, block copolymers could be obtained by sequential addition of the ATRP catalyst, side reactions were observed when all components were present from the start of the reaction. A successful one-pot synthesis was achieved by conducting the reaction in supercritical carbon dioxide. 

Figure 1. GPEC-traces of homopolymer PCL (I M = 13 000 g/mol), P(MMA-b-PCL) obtained in the chemoenzymatic reaction (II M 37 000 g/mol) and homopolymer PMMA (III = 15 000 g/mol). (Reproduced from reference...

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