The coating resist is employed to calculate the reverse impact resistance following Equation (four): Reverse effect resistance (cm/kg) = maximum height 0.91 2.four. Self-Healing Characterization The protocol followed to characterize self-healing behavior was created in the first a part of the study [15]. For every single test, the coatings had been applied on metallic panels to ensure repeatability. The objective of your self-healing property is always to recover the look and mechanical properties. Two Iodixanol Protocol techniques have been employed to quantify these properties: gloss measurements and scratch depth measurements. two.4.1. Self-Healing Characterization by Gloss Measurements abrasion and Washability Tester (Elcometer 1720, Warren, MI, USA) was applied to abrade the coatings at 37 cycles/min (in agreement with typical ISO 11998, 2006). One particular cycle of abrasion meant one back and forth cycle together with the abrasion pad. The abrasions were performed applying a Scotch Brite 7447B (from 3M, Saint Paul, MN, USA) abrasion pad along with a 500 g weight on it. To quantify the gloss recovery, gloss measurements were made making use of the micro-TRIgloss (from BYK, Columbia, SC, USA) at 60 ahead of abrasion, after abrasion, and following healing. A variable number of abrasion cycles had been performed (from 1 to ten). Moreover, healing parameters had been varied to study the influence of heating on the healing efficiency. (4)Coatings 2021, 11,8 ofHeating occasions had been tested from 30 min to 10 h and heating temperature from 60 C to one hundred C. Applying these measurements, the self-healing efficiency was calculated with Equation (five): Self-healing = glosshealed coating – glossdamaged coating glossvirgin coating – glossdamaged coating(5)two.four.2. Self-Healing Characterization by Scratch Depth Measurements The Micro Combi Tester (MCT3, Anton Paar, Graz, Austria) enables to produce controlled scratches, at continual and progressive load. To do so, a 200 radius Rockwell C diamond tip was chosen. Scratches were initially performed at a constant load of five N, having a scratch length of 3 mm and a scratch speed of six mm/min. Scratch depth was then measured with ContourGT-I profilometer (Bruker, Billerica, MA, USA). Coatings were then placed in oven at 80 C for 2 h to evaluate their self-healing behavior. A further profilometry scan was then completed to measure the scratch depth following heating. The details of scratch depth after scratching and heating allows the calculation of self-healing efficiency, following Equation (five), along with the outcomes had been compared working with Tukey statistical analysis: Self-healing efficiency = Depthdamaged coating – Depthhealed coating Depthdamaged coating(six)Secondly, progressive load scratching from 0.3 N to eight N was applied on coatings using exactly the same scratch length and speed parameters described above. As previously, profilometry before and just after heating was performed to measure scratch depth and calculate self-healing efficiency. This test offers information about the self-healing efficiency according to scratch depth along with the maximum load until self-healing behavior is observed. Once more, Tukey statistical evaluation was utilised to examine the results. For both tests, profilometry measurements had been taken in VSI mode (Vertical Scanning Interferometer), with 10magnification, white light supply, and 1 threshold. Profilometry scans have been performed from 20 from the back scan to 30 of scan length. three. Outcomes and Discussion The reference formulation could be the most efficient self-healing coating developed inside the preceding study [15], i.e., the HEMA becryl 4738 fo.