Synthesis of chloromethyl benzimidazole grafted polybenzimidazole with enhanced UV absorption and its effect as a stabilizer on the ultraviolet‐aging behaviors of poly(vinyl chloride) films

Abstract

Poly(vinyl chloride) (PVC) is particularly susceptible to UV damage, and its durability can be reduced substantially when it is exposed to outdoor environments. In this study, high-molecular-weight polybenzimidazole (PBI) was synthesized and then grafted with 2-chloromethyl benzimidazole. The polybenzimidazole grafted with 2-chloromethyl benzimidazole (PBI-g-CMBeIm) could absorb over 99% of UV light in the region 220-420 nm. Then, PVC-PBI-g-CMBeIm blend films were prepared by a solution-casting method, and the effects of the PBI-g-CMBeIm content and UV-irradiation time on the properties of these films were investigated. The results show that the benzimidazole moieties incorporated into the macromolecular chain of PBI provided additional conjugation units, and this allowed the films to have a stronger UV absorption and broader λ range. The yield strength of the PVC-PBI-g-CMBeIm blend films irradiated for 1000 h ranged from 16.5 to 27.7 MPa; this increased 3.2-14.4 MPa compared with that of the pure PVC. The strength retention rate of the pure PVC was 28.8%, whereas that of the PVC-PBI-g-CMBeIm blend films was in the range 34.1-55.2%. The addition of PBI-g-CMBeIm also effectively increased the thermal degradation temperature of the blend films and slowed down their thermal degradation rate.

Synthesis and application of TiO2‐loaded ZnAlSn‐layered double hydroxide compounds as multifunctional nanofillers for polyvinyl chloride

“…The PBI‐g‐CMBeIm could absorb over 99% of UV light in the region 220–420 nm. [ 43 ] In addition, the strength retention rate of PVC‐PBI‐g‐CMBeIm blend films is 34.1%–55.2%, which is 5.3%–26.4% higher than that of pure PVC.…”

“…Irradiated for 1000 h, 34.1%-55.2% of yield strength is retained [43] 3 phr MgCuAl-CO 3 -LDH 400% higher than that of pure PVC of LDHs and TiO 2 -LDHs on the anti-UV-aging properties of PVC composites. As shown in Figure 13, the photoluminescence spectra of LDHs, TiO 2 , and TiO 2 -LDHs are similar in shape with several peaks at 423, 466, 485, and 530 nm.…”

Synthesis and comparative solvatochromic studies of novel Mono azo ureido/thioureido benzimidazole dyes

“…Their characteristic optical linear (Praveen et al , 2015) and second-order non-linear properties (Batista et al , 2007) have been studied and could to be boosted by planting hydroxyl and/or alkoxy substituents (Krawczyk, 2020). The excited state intramolecular proton transfer in these aromatic molecules leads to many fabulous applications such as photo (UV) stabilizers (Franciscato Campo et al , 2006; Ragno et al , 2006; Xu et al , 2019), selective fluorescent biological probes (Xiong et al , 2014), dye sensitizers in solar cells (Bodedla et al , 2016), laser dyes (Yang et al , 2014) and host materials for phosphorescent emitters (Karthik et al , 2016). Upon absorption of UV/Vis-light, charge-transfer (C-T) leads to conformational changes in the excited state, thus dipole moment changes (Ríos Vázquez et al , 2008).…”

Organic-Inorganic Dual-Coated TiO₂ Nanoparticles for Regulation of Photocatalytic Activity

“…2) However, the use of polymers under light causes degradation responsible for yellow discoloration and cracking. 10,11) Ultraviolet (UV) absorbers such as benzotriazole, 12,13) benzimidazole, 14) and benzophenone 15,16) are added into polymers to improve light stability; however, such organic UV absorbers are also gradually decomposed by light irradiation. In the field of inorganic chemistry, semiconductor materials and photocatalysts are representatives of light absorbing materials 17,18) and various photocatalysts for organic matter decomposition and water splitting have been developed.…”