Design and synthesis of a new polymer network containing pendant spiroacetal moieties

Figures & data

Table 1. Copolymerization recipe series (mmol).

Sample code	ItA (mmol)	U (mmol)	AIBN (mmol)	Solvent (ml)
P(ItAU)1:0.5	18.3	9.1	0.21	15.5
P(ItAU)1:1	12.3	12.3	0.21	15.5
P(ItAU)1:1.5	9.2	13.9	0.21	15.5
P(ItAU)1:2	7.5	14.9	0.21	15.5

Figure 1. Schematic illustration of poly(ItA-co-3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5]undecane) (P(ItAU)) copolymer structure.

Figure 2. FT-IR spectra of P(ItAU) copolymers.

Table 2. The absorption peaks corresponding to P(ITAU)_n copolymers.

Compound name	Functional groups	Wavenumber (cm^−1)
ITA/U	C–H stretch; –CH2	2959–2856
ITA	C=O carbonyl	1856–1780
ITA	C=C	1610
ITA/U	–C–H scissoring and bending; –CH2 bending vibrations;	1454–1335
ITA/U	–C–O–C– vibrations	1210–1167
U	–C–O vibrations	1076–988

Figure 3. ¹H-NMR spectra of P(ItAU) copolymers synthesized in 1,4 dioxane as reaction media.

Figure 4. Determined molecular weights of P(ItAU)_1:0.5 (a) and of P(ItAU)_1:1.5 (b).

Table 3. Thermal parameters of studied copolymers.

Copolymer samples	Degradation stage	Tonset (°C)	Tpeak (°C)	Tendset (°C)	ΔW (wt %)	T10 (°C)	T20 (°C)
P(ItAU)1:0.5	I	117	140	147	6.90	165	195
	II	156	177	216	30.18
	III	378	428	471	49.55
	Residue				13.37
P(ItAU)1:1	I	122	164	170	13.57	160	191
	II	173	185	242	22.36
	III	381	427	472	51.90
	Residue				12.17
P(ItAU)1:1.5	I	125	177	242	22.87	192	274
	II	376	425	475	63.76
	Residue				13.37
P(ItAU)1:2	I	109	205	279	37.40	178	215
	II	372	422	470	51.70
	Residue				10.90

Notes: T_onset – temperature at which the thermal decomposition begins; T_peak – temperature at which the degradation rate is maximum; T_endset – temperature at end of the process; T₁₀ and T₂₀ – temperature corresponding to 10 and 20% respectively, weight loss; W – weight losses.

Figure 5. TG and DTG curves of the studied copolymers variants.

Figure 6. Evolution of the polymeric particles dimension with temperature.

Figure 7. Variation of viscosity with shear rate for the copolymers solutions of various concentrations.