Intramolecular Lactonization of Poly(α-hydroxyacrylic acid): Kinetics and Reaction Mechanism

Table 4

PCA parameters describing the dominating spectral characteristics in the ¹H NMR domain of lactone formation of PHA in the range of pH 1 to 5.

pH	Explained by PC1	Explained by PC2	Explained PC1 + PC2	Chem.shift PC1	Chem.shift PC2	Time at max. PC1	Time at max. PC2
	%	%	%	ppm	ppm	min	min
1	88.5	8.1	96.6	2.767	2.442	1600	90
2	87.5	10.1	97.6	2.761	2.416	1720	90
3	82.6	12.4	95.0	2.742	2.580	1500	50
4	77.9	18.0	95.9	2.717	2.397	1600	60
4.5	79.4	17.5	96.9	2.636	2.335	1600	60
5	86.1	9.3	95.4	2.561	2.297	1600	90