The authors reported the synthesis of biobased adhesive derived from caffeic acid. The scope of this paper is important for sustainable chemistry and materials, and it is suitable for this journal, RSC Sustainability. The data of controlled RAFT polymerization and the properties of adhesive are excellent. The reviewer recommends that this paper would be acceptable for publication in RSC Sustainability after revisions for the following comments.

1. Why was ethyl acetate selected as a solvent for the polymerization. Can other solvents be used? Describe the reason if there is.
2. The description of the purification of Boc2VC polymer is recommended to be included in the main text.
3. The line connecting the data of Mw/Mn in Figure 1B may be straight. Is there a reason for the slight curve?
4. The Mn and Mw/Mn values of the polymer product synthesized by free radical polymerization are shown as 1,070,000 and 3.60, respectively in page 7. However, the values are shown as 393300 and 2.33 in the supporting information in page S4. There are differences.
5. The section of Measurement in the supporting information should be moved to its usual place that is after the section of Materials. I had looked for the section.
6. Table S1, results of polymerization of Boc2VC, should be presented in the main text because these data are important. In addition, I recommend that the result by free radical polymerization is included in the table.

The manuscript was revised. The following points are necessary to make clear before publication.

1. The line connecting the data of Mw/Mn in Figure 1B may be straight. Is there a reason for the slight curve?

   We do not think there is a reason for the Mw/Mn to vary linearly with the conversion in this polymerization system. The curve has been modified to better illustrate the trend.

[Comment] The authors only described that the molecular weight distributions (Mw/Mn) were narrow (ca. 1.1). I recommend that the detailed explanation of the above is added to the manuscript.

1. The Mn and Mw/Mn values of the polymer product synthesized by free radical
   polymerization are shown as 1,070,000 and 3.60, respectively in page 7. However, the values are shown as 393300 and 2.33 in the supporting information in page S4. There are differences.

   The Mn and Mw/Mn values varied depending on the polymerization conditions (e.g., reaction time). The values are different because we have performed the synthesis of P(Boc2VC) by free radical polymerization multiple times in the study. The procedure shown in Page S4 correlates with the data presented in Figure S4.

[Comment] I recommend that the text clearly state that the conditions for free radical polymerization data in page 4 and Figure S4 are different. In addition, why the conditions are different?

1. Table S1, results of polymerization of Boc2VC, should be presented in the main text because these data are important. In addition, I recommend that the result by free radical polymerization is included in the table.

   The important data (i.e., molecular weight and dispersity) presented in Table S1 is already shown in Figure 2, and we are afraid showing both Figure 2 and Table S1 is redundant. Figure 2 also shows a linear relationship between the feed ratio and molecular weight, which is difficult to get from Table S1. The data for the free radical polymerization somewhat differs from the point of the Figure/Table as the point was that we can control the molecular weight by the polymerization conditions.
   [Comment] Why are all data in Table S1 not adopted as Figure 2? My pointing out is that the both data are not the same. For example, the data of monomer/CDB = 1000 is shown in the figure and the table. While the data of monomer/CDB = 50 in Figure 2 are not same with that in Table S2. Showing one data set is enough. The detailed data of the figure should be shown in the table in the supporting information to avoid confusion.

This manuscript will be published after the following one minor revision.

• Figure 2 has no label on 2nd y-axis.