Studies of miscibility and specific interactions of antitumor-active anhydride copolymer and poly(ethylene glycol) blends

Figures & data

Table I. Summary of equations of miscibility parameters (Δb, Δk, α, β, ΔB, and μ).

Scheme 1. Representation of the copolymerization of acrylic acid and maleic anhydride monomers.

Figure 1. ATR-FTIR spectrum of poly(MA-alt-AA) copolymer [MA with AA was carried out in p-dioxane in the presence of benzoyl peroxide (BPO) (0.1%) as an initiator at 70°C, under a nitrogen atmosphere, for an 8 h monomer feed MA/AA →50/50].

Figure 2. ATR-FTIR spectra of poly(MA-alt-AA)/PEG; (a) 0/100, (b) 25/75, (c) 50/50, (d) 75/25 and (e) 100/0.

Scheme 2. Partial and reversible hydrolysis of poly(MA-alt-AA).

Figure 3. ¹H-NMR spectra of poly(MA-alt-AA)/PEG blends (a) 0/100, (b) 25/75, (c) 50/50, (d) 75/25 and (e) 100/0 in DMSO-d₆ at 25°C.

Table II. DTA and TGA data for the pure polymers and their blends ratios of poly(MA-alt-AA)/PEG; 0/100, 25/75, 50/50, 75/25 and 100/0.

PEG:Poly(MA-alt-AA) Blends	Tg (°C)	% Weight Loss- Temperature (^oC)
		100	200	300	400	500
PEG/poly(MA-alt-AA) (100/0)	62	0.9	0.7	2.9	40.5	52.8
PEG/poly(MA-alt-AA) (75/25)	65	0.9	4.3	6.5	16.8	64.0
PEG/poly(MA-alt-AA) (50/50)	127	0.8	10.6	14.6	23.5	50.6
PEG/poly(MA-alt-AA) (75/25)	147	3.3	22.5	15.1	22.2	34.6
PEG/poly(MA-alt-AA) (0/100)	142	1.0	22.6	19.4	12.5	14.7

Figure 4. TGA thermograms of poly(MA-alt-AA)/PEG blend compositions (1) 0/100, (2) 25/75, (3) 50/50, (4) 75/25 and (5) 100/0.

Figure 5. Graph of poly(MA-alt-AA)/PEG; (1) 0/100, (2) 25/75, (3) 50/50, (4) 75/25 ve (5) 100/0 blend ratio of viscosity experiments η_sp/c -c in water at 25°C ± 0.1.

Figure 6. Viscosity graph of poly(MA-alt-AA)/PEG; (1) 0/100, (2) 25/75, (3) 50/50, (4) 75/25 and (5) 100/0 blend ratio of viscosity experiments η_sp/c-c in p-dioxane at 25°C ± 0.1.

Table III. Huggins constant, k_H, and intrinsic viscosity [η], calculated according to the Huggins equation, with different mixing ratios of poly(MA-alt-AA):PEG at 25°C ± 0.1 in water.

PEG/poly(MA-alt-AA) Blend Solutions	[η] (dL/g)	kH
PEG/poly(MA-alt-AA) (100/0)	0.00300	0.1257
PEG/poly(MA-alt-AA) (75/25)	0.09933	0.1118
PEG/poly(MA-alt-AA) (50/50)	0.04512	0.1494
PEG/poly(MA-alt-AA) (75/25)	0.05170	0.1573
PEG/poly(MA-alt-AA) (0/100)	0.07415	0.1040

Table IV. Calculated intrinsic viscosity, [η], and Huggins constant, k_H, according to the Huggins equation in the viscosity experiments of poly (MA-alt-AA)/PEG, with different mixing ratio at 25°C ± 0.1 in water.

Poly (MA-alt-AA)/PEG	b (dl/g)^2	[η]m (dL/g)	Δb	Δk	α	β	Δβ	μ
0/100	1.1313*10^− 4	0.00300	–	–	^−	–	–	–
25/75	2.4870*10^− 5	0.02078	− 5.70*10^− 7	− 2.5*10^− 3	− 4.59*10^− 4	− 4.83*10^− 4	− 2.616*10^− 4	− 0.05167
50/50	3.3234*10^− 5	0.03858	7.794*10^− 6	0.0351	2.6*10^− 3	2.62*10^− 3	− 2.533*10^− 4	− 0.0500
75/25	3.5000*10^− 5	0.05637	9.560*10^− 6	0.0430	1.115*10^− 3	1.13*10^− 3	− 2.514*10^− 4	− 0.0497
100/0	5.7187*10^− 4	0.07415	–	–	–	–	–	–

Scheme 3. Poly(MA-alt-AA) and PEG molecular interactions via hydrogen bonding and other electrostatic interactions.