Photopolymerization kinetics and properties of a trifunctional epoxy acrylate

Figures & data

Chart 1 The structures of reactive diluents.

Table 1. Properties of cured films.

Samples	Viscosity (pa. s)	T g (°C)	ρ (mmol/cm^3)	Pencil hardness^a
75% Tri-EA + 25% SR351	56.8	112.1	434.67	>6H
75% Tri-EA + 25% SR306	30.7	108.2	148.45	>6H
75% Tri-EA + 25% HEA	23.5	99.3	83.99	>6H
75% EA + 25% SR306	12.6	68.6	49.81	6H
^aAccording to China national standards GB/T6739-1996.

Scheme 1 The synthesis process of EA.

Figure 1 Effect of photoinitiator concentration on photopolymerization of 75%Tri-EA + 25% SR306. Inset: R _p plots (I = 25 mW/cm²).

Figure 2 Effect of different photoinitiators on the photopolymerization of 75%Tri-EA + 25% SR306. Inset: R _p plots (I = 25 mW/cm²).

Figure 3 Effect of the light intensity on the photopolymerization of 75%Tri-EA + 25% SR306. Inset: linear regressions with R = 0.974 (1173 = 1.0%).

Figure 4 Conversion vs. irradiation time plot for Tri-EA with different functional reactive diluents. Inset: plots (1173 = 1.0%, I = 25 mW/cm²).

Figure 5 Comparison of polymerization conversion rate for Tri-EA/SR306 and EA/SR 306. Inset: R _p plots (1173 = 1.0%, I = 25 mW/cm²).

Figure 6 Storage modulus E′ (a) and the loss factor tanδ (b) for different cured films.

Figure 7 TGA measurements of different cured flims.

Table 2. TGA of cured flims.

Samples	T d,10% (°C)^a	T d,50% (°C)^b	T max (°C)^c	Char600 °C (%)
75% Tri-EA + 25% SR351	391.3	445.9	436.1	20.2
75% Tri-EA + 25% SR306	373.1	439.6	426.3	16.0
75% Tri-EA + 25% HEA	366.1	425.6	417.3	16.3
75% EA + 25% SR306	371.2	429.5	413.7	12.9
^aTemperature of 10% weight loss.^bTemperature of 50% weight loss.^cTemperatures of maximum weight-loss rate.

Figure 8 The adhesive strength of different cured systems in glass (A) 75%Tri-EA + 25% HEA, (B) 75%Tri-EA + 25% SR306, (C) 75% Tri-EA + 25% SR351, and (D) 75% EA + 25% SR306.