The surface of chemically modified polytetrafluoroethylene, obtained by introducing 1 mol % perfluoropropyl vinyl ether in the polytetrafluoroethylene macromolecule chain, has been studied using Raman spectroscopy. Three conventional zones with varying degrees of modification are distinguishable on the surface, and the spectrum of the ablation crater is fundamentally different from that of the pristine polymer. The crater spectrum, showing a general rise in the baseline, exhibits new bands due to both double carbon bonds and absorption bands of CF3 groups. A key factor in the laser ablation process is the influence of defects in the regular structure of polymer macromolecules, both intrinsically present in the polymer and induced by laser irradiation.

The formation of laser thrust by the pressure of gases released from the crater of laser ablation of polytetrafluoroethylene in vacuum has been studied, and a model for calculating the mechanical recoil impulse of ablation products has been implemented on the basis of a gravimetric curve obtained using an electronic balance that allows direct recording during intermittent (at 5-s intervals) or continuous irradiation for 5, 10, 15, 25, and 30 s with an infrared CO2 laser. Regardless of the laser operation mode, the observed polymer weight loss by ablation is linearly related to the laser irradiation time, having a rate of 80 μN/s. The maximum mechanical recoil impulse, which appears on the gravimetric ablation curves 4.5 ± 0.3 s after the laser is switched on, is 145 ± 7 or 90 ± 20 μN s in the continuous or the intermittent irradiation mode, respectively. In this case, an increase in the time of laser irradiation of the polymer in both modes leads to an insignificant change in the specific mechanical recoil impulse within 2.76 ± 0.06 μN/J. The results of the study show the possibility of using a polytetrafluoroethylene target for laser thrust, and the method of calculating the force momentum from the gravimetric curve of ablation of polytetrafluoroethylene can be used to investigate the mechanism of laser ablation of other polymer targets.

In the course of γ-irradiation at 77 K, polyvinyl alcohol accumulates alkyl radicals (formed upon hydrogen atom abstraction) and radical anions (resulting from electron addition to the acetate group remaining after the saponification of polyvinyl acetate in the course of polyvinyl alcohol production on its basis). Upon the radiolysis of polyvinyl alcohol at 300–341 K, polyenyl radicals with a singlet spectrum were detected in the EPR spectrum in addition to the triplet of alkyl radicals.

Irradiation with γ-rays fundamentally changes the IR spectrum of polyvinyl alcohol, resulting in a decrease in the intensity of absorption bands due to OH and CH groups and the appearance of new bands due to the vibrations of unsaturated bonds. An increase in the γ-radiation dose from 100 to 3500 kGy barely leads to the appearance of new absorption bands; in this case, a complex series of absorption bands arises and the intensity of bands existing in a frequency range characteristic of the stretching vibrations of unsaturated bond groups increases. In turn, these tendencies are reflected in color changes after γ-irradiation, and they also indicate the radiation-induced carbonization of the polymer chain. The study of acute toxicity and the class of acute toxicity of the initial polyvinyl alcohol and its analogue γ-irradiated to 2000 kGy allows them to be categorized with class 4 low-toxicity drug compounds.

The irradiation of a poly(vinylidene fluoride) (PVDF) plate with γ-rays up to 100 kGy leads to the breaking of the chain and the formation of unsaturated bonds but practically does not have any effect on the conformation composition of PVDF macromolecules. The main conformer, as in native PVDF, is the β form. Irradiation with an IR laser leads to a noticeable carbonization of PVDF macromolecules and is accompanied by a structural transition of polymer macromolecules from the β conformer to the α conformer. In the IR spectrum of the powdered product from laser ablation of PVDF, in addition to the absorption bands of the ablation crater, absorption bands from the parent PVDF are still present.

Irradiation of polyamide-6 (PA) with γ-rays reduces its resistance to subsequent IR laser radiation. The average rate of laser ablation of PA, preliminarily irradiated with γ-rays at a dose above ~300 kGy, is almost dose-invariant and is 30% higher than that of the initial unirradiated polymer. The pattern of the dose dependence of the laser ablation rate for the samples pre-irradiated with a dose of 3.24 MGy at a dose rate of 4.2 Gy/s is mixed in character, varying from the shape characteristic of the initial polymer at the initial stage to the shape typical of the maximum radiation dose in the stationary laser ablation mode. One of the products of PA laser ablation is a dispersed polymer, consisting of nano- to micrometer-sized particles, the size range of these particles shifting toward smaller values with an increase in the γ radiation dose, a trend that is explained by a decrease in melt viscosity.

The effect of preliminary γ-irradiation on accelerating the speed of laser ablation of a polyamide is measured for the first time. A linear increase of intensity with a rate of 0.15 mg/s is observed during laser ablation of the polyamide pre-irradiated with γ-rays at a dose of 3,500 kGy. A γ-radiolysis dose of 10 – 20 kGy causes extreme changes in the molecular-topological parameters and the maximum level of growth of the rate of laser ablation. Thus pre-irradiation with γ-rays may be used to optimize the laser ablation of the polymer.

The molecular–topological structure of a tetrafluoroethylene copolymer with ethylene after γ-irradiation and thermal annealing has been studied. The pseudo-network structure of the copolymer contains, in addition to the amorphous block, crystalline segments of macromolecules in the role of branching sites. Topologically, the diblock structure of the copolymer after thermal annealing at 538 K is transformed into a three-block structure with the appearance of a high-temperature amorphous block. Irradiation of the copolymer with γ-rays to a dose of 150 kGy does not lead to appreciable changes in its molecular–topological structure.