1：Experimental Design and Method Selection:

The study involved synthesizing a photocurable urethane prepolymer by grafting a polyether polyol with 3-isopropenyl-α,α-dimethylbenzyl isocyanate to functionalize it with photocurable groups. CNC was dispersed in the polyol via solvent exchange, and the prepolymer was synthesized under nitrogen atmosphere with a bismuth carboxylate catalyst. UV-curable resins were prepared by adding photoinitiators and a reactive diluent, followed by curing under UV light.

2：Sample Selection and Data Sources:

CNC polyol suspensions were produced with CNC concentrations of

3：4 wt%, 8 wt%, and 6 wt% in the polyol, leading to resin CNC concentrations of 1 wt%, 3 wt%, and 5 wt%. Coatings and free films were prepared on glass substrates. List of Experimental Equipment and Materials:

Equipment includes a wiped-film evaporator, 3-necked reactor with Teflon stirrer, ATR-FTIR spectrometer (Platinum ATR Alpha, Bruker), rotational rheometer (Advanced Rheometer AR 2000, TA Instruments), ultrasonicator (Sonic Dismembrator Model 100, Fisher Scientific), UV-curing unit (Mini Laboratory Unit, GEW), SEM (Zeiss Sigma Field Emission SEM), abrasion tester (5130 Abraser, TABER Industries), adhesion tester (Elcometer 106, Elcometer Limited), tensile tester (Shimadzu AGS-X), and DSC (TA Q100, TA Instruments). Materials include Carpol GP 725 polyol, TMI isocyanate, Valikat Bi 2010 catalyst, Genomer 1225 reactive diluent, DMPA, DMHA/TPO photoinitiator blend, and CNC.

4：Experimental Procedures and Operational Workflow:

CNC was dispersed in polyol using solvent exchange. Prepolymer synthesis involved reacting polyol with TMI at 50°C. Resins were formulated, mixed via ultrasonication and vortex mixing, coated onto glass, and cured under UV light. Properties were characterized using FTIR, rheology, DSC, tensile testing, abrasion testing, and adhesion testing.

5：Data Analysis Methods:

Statistical analyses included ANOVA with Tukey or Games-Howell post hoc tests using R and OriginPro software. FTIR data were analyzed with OMNIC software, and other data were processed according to ASTM standards.