Azo polymers for reversible optical storage. 11 poly {4,4′-(1-Methylethylidene)Bisphenylene 3-[4[(4-Nitrophenylazo)Phenyl]-3-Aza-Pentanedioate}

Novel polyesters with amino-sulfone azobenzene chromophores in the main chain

“…The level of induced birefringence tends to be higher for polymers with higher TP contents. These data are consistent with the results of the curve fitting for E n based on the first 500 s of relaxation (Table II) and show stability nearly as high as that reported for the side‐chain polymers pDR1M, pMNAP,21 and pANPP22 incorporating amino‐nitro azobenzene groups (structures are shown in Scheme ).…”

“…The level and kinetics of photoinduced birefringence of the 9a – 9d polymers containing TP groups in the backbone are similar to those of the side‐chain polymers with substituted azo groups. Because the more rigid linkage restricts the mobility of the azo groups and thus can hinder both their orientation and relaxation, the result may be lower levels of photoinduced birefringence, as was observed for pMNAP 21. One can consider a progression of strength of the bond between the azo group and the polymer chain as follows: the bond in pDR1M is the weakest, followed by pANPP,22 where there are two connection points, then by pMNAP,21 where the two connections are part of the main chain (see Scheme ), and finally by the polymers that are the subject of this article, where the azo groups are not in the side chain, as in the previous cases, but are part of the main chain.…”

Novel polyesters with amino-sulfone azobenzene chromophores in the main chain

“…The level of induced birefringence tends to be higher for polymers with higher TP contents. These data are consistent with the results of the curve fitting for E n based on the first 500 s of relaxation (Table II) and show stability nearly as high as that reported for the side‐chain polymers pDR1M, pMNAP,21 and pANPP22 incorporating amino‐nitro azobenzene groups (structures are shown in Scheme ).…”

“…The level and kinetics of photoinduced birefringence of the 9a – 9d polymers containing TP groups in the backbone are similar to those of the side‐chain polymers with substituted azo groups. Because the more rigid linkage restricts the mobility of the azo groups and thus can hinder both their orientation and relaxation, the result may be lower levels of photoinduced birefringence, as was observed for pMNAP 21. One can consider a progression of strength of the bond between the azo group and the polymer chain as follows: the bond in pDR1M is the weakest, followed by pANPP,22 where there are two connection points, then by pMNAP,21 where the two connections are part of the main chain (see Scheme ), and finally by the polymers that are the subject of this article, where the azo groups are not in the side chain, as in the previous cases, but are part of the main chain.…”

Photoinduced orientation and cooperative motion of three epoxy-based azo polymers

“…The molecular orientation in the polymer films can be quantitatively characterized by the birefringence measurement, polarized UV-Vis spectroscopy, and polarized IR spectroscopy [14,15,24,25]. In past decades, the correlation between the photoinduced orientation and molecular structures has been extensively studied for both liquid crystal azo polymers [12,13,[29][30][31][32][33], and amorphous azo polymers [16][17][18][19][20][21][22][23][24]. Understanding of the structure-property relationships has been used to elucidate the mechanism and develop materials with better performance.…”

Photoinduced Birefringence and Surface Relief Gratings in Novel Polyurethanes with Azobenzene Groups in the Main Chain

“…However, the relative stability of the photoinduced birefringence is constant for PU1 and PU2 , even at the temperatures close to T g , although the photostationary and the stable values decrease with the increase of temperature. The behavior of PU3 is very similar to that of other side-chain azo polymers; thus, incorporation of the azobenzene chromophore into the polymer main chain does not increase the stability of the induced birefringence.

6 Long-term stable birefringence, E n , as a function of reduced temperature.

…”

Novel polyesters with amino-sulfone azobenzene chromophores in the main chain

“…The level of induced birefringence tends to be higher for polymers with higher TP contents. These data are consistent with the results of the curve fitting for E n based on the first 500 s of relaxation (Table II) and show stability nearly as high as that reported for the side‐chain polymers pDR1M, pMNAP,21 and pANPP22 incorporating amino‐nitro azobenzene groups (structures are shown in Scheme ).…”

“…The level and kinetics of photoinduced birefringence of the 9a – 9d polymers containing TP groups in the backbone are similar to those of the side‐chain polymers with substituted azo groups. Because the more rigid linkage restricts the mobility of the azo groups and thus can hinder both their orientation and relaxation, the result may be lower levels of photoinduced birefringence, as was observed for pMNAP 21. One can consider a progression of strength of the bond between the azo group and the polymer chain as follows: the bond in pDR1M is the weakest, followed by pANPP,22 where there are two connection points, then by pMNAP,21 where the two connections are part of the main chain (see Scheme ), and finally by the polymers that are the subject of this article, where the azo groups are not in the side chain, as in the previous cases, but are part of the main chain.…”

Photoinduced orientation and cooperative motion of three epoxy-based azo polymers

“…The molecular orientation in the polymer films can be quantitatively characterized by the birefringence measurement, polarized UV-Vis spectroscopy, and polarized IR spectroscopy [14,15,24,25]. In past decades, the correlation between the photoinduced orientation and molecular structures has been extensively studied for both liquid crystal azo polymers [12,13,[29][30][31][32][33], and amorphous azo polymers [16][17][18][19][20][21][22][23][24]. Understanding of the structure-property relationships has been used to elucidate the mechanism and develop materials with better performance.…”

Photoinduced Birefringence and Surface Relief Gratings in Novel Polyurethanes with Azobenzene Groups in the Main Chain

“…However, the relative stability of the photoinduced birefringence is constant for PU1 and PU2 , even at the temperatures close to T g , although the photostationary and the stable values decrease with the increase of temperature. The behavior of PU3 is very similar to that of other side-chain azo polymers; thus, incorporation of the azobenzene chromophore into the polymer main chain does not increase the stability of the induced birefringence.

6 Long-term stable birefringence, E n , as a function of reduced temperature.

…”

Novel polyesters with amino-sulfone azobenzene chromophores in the main chain

“…The level of induced birefringence tends to be higher for polymers with higher TP contents. These data are consistent with the results of the curve fitting for E n based on the first 500 s of relaxation (Table II) and show stability nearly as high as that reported for the side‐chain polymers pDR1M, pMNAP,21 and pANPP22 incorporating amino‐nitro azobenzene groups (structures are shown in Scheme ).…”

“…The level and kinetics of photoinduced birefringence of the 9a – 9d polymers containing TP groups in the backbone are similar to those of the side‐chain polymers with substituted azo groups. Because the more rigid linkage restricts the mobility of the azo groups and thus can hinder both their orientation and relaxation, the result may be lower levels of photoinduced birefringence, as was observed for pMNAP 21. One can consider a progression of strength of the bond between the azo group and the polymer chain as follows: the bond in pDR1M is the weakest, followed by pANPP,22 where there are two connection points, then by pMNAP,21 where the two connections are part of the main chain (see Scheme ), and finally by the polymers that are the subject of this article, where the azo groups are not in the side chain, as in the previous cases, but are part of the main chain.…”

Photoinduced orientation and cooperative motion of three epoxy-based azo polymers

“…The molecular orientation in the polymer films can be quantitatively characterized by the birefringence measurement, polarized UV-Vis spectroscopy, and polarized IR spectroscopy [14,15,24,25]. In past decades, the correlation between the photoinduced orientation and molecular structures has been extensively studied for both liquid crystal azo polymers [12,13,[29][30][31][32][33], and amorphous azo polymers [16][17][18][19][20][21][22][23][24]. Understanding of the structure-property relationships has been used to elucidate the mechanism and develop materials with better performance.…”

Photoinduced Birefringence and Surface Relief Gratings in Novel Polyurethanes with Azobenzene Groups in the Main Chain

“…However, the relative stability of the photoinduced birefringence is constant for PU1 and PU2 , even at the temperatures close to T g , although the photostationary and the stable values decrease with the increase of temperature. The behavior of PU3 is very similar to that of other side-chain azo polymers; thus, incorporation of the azobenzene chromophore into the polymer main chain does not increase the stability of the induced birefringence.

6 Long-term stable birefringence, E n , as a function of reduced temperature.

…”