Synthesis of Block Copolymers of Varying Architecture Through Suppression of Transesterification during Coordinated Anionic Ring Opening Polymerization

Table 1

Characteristics of triblock copolymers PCL-PLA-PCL synthesised with the use of different protective substances.

N	Protective additive	Mn (SEC), Da, (Mn/Mw)	Crystallinity (%) and (melting temperature (^°C))		PCL/PLA segment length, monomer units
			PCL	PLA
1	α-Methyl styrene	73,175 (1.51)	43.8 (52.4)	52.6 (165.3)	36.2/49.3
2	Styrene	71,435 (1.56)	26.5 (49.4)	42.7 (164.9)	17.5/51.1
3	Ethyl benzoate	58,310 (1.71)	—	30.0 (154.8)	13.0/21.1
4	Diethyl hexyl phthalate	43,910 (1.60)	—	19.1 (127.4)	7.0/11.9
5	Dioctyl phthalate	45,275 (1.61)	—	21.9 (140.1)	6.7/14.0
6	Diallyl phthalate	60,530 (1.61)	—	17.5 (135.8)	6.1/10.9
7	No additive	45,060 (1.72)	—	—	5.8/7.8