Polymer degradation kinetics^a.

Entry	Polymerb	pHc	t 1/2 (min)	Timed (h)	Conv.e (%)	Pdt. 1f (%)		Pdt. 2f (%)
1	P1+	5.1	29	3.0	87	5	49	6	29
2	P(1+Cl−)	5.1	33	3.0	84	5	48	6	34
3	P1+	6.5	3.8	1.5	100	5	54	6	28
4	P1+	7.0	<3	1.0	96	5	59	6	15
5	P1+	Et3Ng	6.4	3.0	86	5	85	6	0
6	P2+	5.1	77	3.0	87	—	—	8	85
7	P2+	6.5	7.6	0.4	94	—	—	8	97
8	P3+	7.0	201	10.0	69	9	35	10	33
9	P3+	7.5	42	3.0	69	9	52	10	18
10	P3+	∼9h	13	16.8	100	9	85	10	<5
11	P4+	5.1	443	10.4	56	11	45	12	9
12	P4+	6.5	15	3.0	100	11	87	12	12
13	P4+	7.0	<3	1.0	100	11	95	12	5

^aReactions done in duplicate at 25 °C, [polymer]₀ = 40–60 mM (calculated with respect to repeat units) in a 1 : 1 mixture of buffer and D₂O and quantified by ¹H NMR with an internal standard. Dashed entries unknown or not accurately quantified.

^bDefault counteranion trifluoroacetate; typical polymer lengths were P165+, P248+, P375+, and P448+.

^cAll pH degradation experiments were conducted in deuterated NMR buffers. The pH indicated were measured upon dilution of these buffers with distilled H₂O. The pH 5.1 buffer was made with acetic acid-d₄/NaOH, and the pH 6.5, 7.0, and 7.5 buffers with KH₂PO₄/K₂HPO₄ in D₂O (see ESI for details).

^dTime at which the next three data columns are measured.

^ePercentage of starting esters that have disappeared.

^fPercentage of starting esters incorporated into this product.

^gDegradation carried out with 2.5 eq. Et₃N in CD₃OD.

^hSaturated NaHCO₃ in D₂O, used without dilution.