A Theoretical and Experimental Study on Esterification of Citric Acid with the Primary Alcohols and the Hydroxyl Groups of Cellulose Chain (n = 1-2) in Parched Condition

Table 1

Energy barrier of ring opening step in relation to the substituent R, which owns the +I effect in R-CH₂-OH.

No.	Substituent R	Ea4	Ea5	Ea6
1	H	25.0	28.2	21.1
2	CH3	25.2	28.4	21.1
3	CH2CH3	25.1	28.4	21.0

The unit of E_a4, E_a5, and E_a6 is kcal/mol.