## 3 Results and Discussion
### Stain Recovery and Stain Resistance  
The main advantage of a stain resistant and stain recovery finish for fabric is that, when a spill occurs, it can be cleaned easily. Removal of stains during low temperature home launderings is often recommended. Assessment of performance under such conditions can be done according to standard tests, such as AATCC test 130. Results for stain release (Table 1) roughly followed the oil repellency findings except the woven commercial fabric received a lower rating than the commercial interlock fabric. At a grade of 4.5, sample PA2 received the highest rating of the group and PA1 the poorest at 1.  
Fabrics were stained with oil, mustard and ketchup in additional tests. On the basis of the oil repellency and oil release results, sample PA1 was excluded from further testing. After wiping the stain with a tissue paper, stains remained visibly attached to untreated cotton, but, for treated fabric with PA2, all the stains were wiped away. To quantify this, we measured the reflectance of the fabric after wiping the stains for oil, mustard and ketchup. Figure 9 shows the stain resistance performance of treated cotton with PA2 and untreated cotton. PA2 exposed to oil showed stain resistance of 100% indicating oil can be wiped off immediately. When stains were dropped on untreated cotton, stains penetrated and contributed to lower reflectance. For treated cotton, the various agents did not penetrate and could be wiped off easily so reflectance retuned nearly to 100%.  
Staining tests were also performed on the commercial reference samples and compared with PA2. Figure 10 presents reflectance measurements of stain resistance for treated and reference samples after exposure to oil, mustard and ketchup. All fabrics performed well in resisting blemishes by oil. Overall, PA2 performed comparably to the woven commercial material and outperformed the commercial knit.  
\begin{table}
\begin{tabular}{l c} \hline \hline
**Types of fabric** & **Stain release grade** \\ \hline Interlock (PA1) & 1 \\ Interlock (PA2) & 4.5 \\ Interlock (Ref. 1) & 3 \\ Woven (Ref. 2) & 2 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Stain release grades according to AATCC test method 130.  
Figure 8: Comparison of oil test for treated fabric with commercial reference samples.  
The commercial interlock type fabric (Ref. 1) showed poor performance compared to the fabric modified by admicellar polymerization with only about 75% of stain resistance with mustard and about 80% with ketchup. It is a significant finding that the coated cotton knit could function at a level comparable to a fabric with a tighter weave.  
Similar experiments for stain recovery of the fabric were carried out by doing one home laundering and then assessing the level of stain recovery using reflectance measurements. Results for stain recovery are presented in Figure 11. All materials perform well in removal of oil by washing. Otherwise, stain recovery of PA2 was substantially better than the reference samples.  
Figure 10: Stain resistance comparison for PA2 and commercial fabrics with different stains.  
Figure 9: Stain resistance for untreated and treated fabric with PA2 with different staining agents.