## 3 Results and Discussion
### Cross-Linking Performance of Glycosl Anti-Wrinkle Finishing Agent  
The anti-wrinkle finishing agent will react with cellulose from being absorbed onto the surface of the fiber and being diffused into the fiber. The degree of crosslinking was mainly affected by the type and number of reactive groups of the finishing agent molecule [15; 16; 22; 23]. Therefore, by analyzing the influencing factors of the aldol reaction and the esterification reaction between the finishing agent and cellulose, the number of reactive groups and rotatable bonds of the finishing agent, the cross-linking performance of glucose, OFr, OSu, OTr, openSu, openTr, BTCA, GA, and DMDHEU can been analyzed. The molecular structures of different finishing agents at the lowest energy are shown in  
Figure 5: CSEV of different anti-wrinkle finishing agents. Figure 6, and the number of reactive groups and rotatable bonds of the finishing agent are shown in Table 1.  
In Figure 6, there are mainly two types of reactive groups (carboxyl group and aldehyde group) of the nine anti-wrinkle finishing agents. According to the esterification reaction mechanism in polycarboxylic acids, more than two carboxyl groups are required to be dehydrated into an acid anhydride, which can react with the hydroxyl group of cellulose [2; 5; 6; 7]. Therefore, a single carboxyl group cannot be used as a reactive group. As to BTCA, there were four carboxyl groups in the molecule; according to the reaction mechanism of the two-by-two acid anhydride formation between the carboxyl groups, the maximum number of carboxyl groups that can form an esterification reaction was three, but there were two trans-COOH of BTCA, which made it difficult to form an anhydride; therefore, the number of reactive groups of BTCA was four, and the number of reaction sites was two or three. According to the aldol etherification reaction mechanism, after the aldehyde group reacted with the hydroxyl group to form an ether bond, this aldehyde group formed a highly reactive hydroxyl group, which can also continue to react with the hydroxyl group of cellulose; therefore, an aldehyde group will react with two hydroxyl groups. Using glutaraldehyde (GA) as an example, there were two aldehyde groups, assuming the aldehyde groups can fully react with the hydroxyl groups of cellulose to form four ether bonds [10; 11]. Therefore, the number of reactive groups of GA was two and the number of reaction sites was four. The reactive group of DMDHEU was N-hydroxymethyl, which formed an ether bond with the hydroxyl group of cellulose [1; 3; 4]. One N-hydroxymethyl can only form one ether bond; therefore, the number of reactive groups of DMDHEU was two and the number of reaction sites was two. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Finishing Agents** & **Molecular Weight** & **PCG** & **NRS** & **RBN Value** \\ \hline Glucose & 180.156 & 1 & 2 & 5 \\ Ofr & 178.140 & 2 & 4 & 6 \\ OSu & 354.264 & 4 & 8 & 14 \\ OTr & 338.265 & 4 & 8 & 14 \\ openSu & 396.213 & 7 & 9,10 & 14 \\ openTr & 366.231 & 6 & 9 & 14 \\ DMDHEU & 324.252 & 2 & 2 & 6 \\ GA & 100.117 & 2 & 4 & 4 \\ BTCA & 234.160 & 4 & 2,3 & 7 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of cross-linking properties of different finishing agent molecules. Figure 6: Molecular structure of different finishing agents at the minimum energy. Through these three calculation methods, the number of reactive groups and the number of reaction sites of the nine anti-wrinkle finishing agents are summarized in Table 1, and the number of rotatable bonds (RBN value) of the different finishing agents are also summarized. The RBN value can be used to analyze the flexibility of the finishing agent molecule, which can indicate the possibility of the finishing agent colliding with the hydroxyl group of the cellulose. The larger the RBN value is, the more likely the finishing agent molecules is to rotate, and the cross-linking efficiency of the finishing agent and cellulose were also higher.