Functionalized oligomers and polymers as stabilizers for conventional polymers

Synthesis of Silicon Quantum Dots with Highly Efficient Full-Band UV Absorption and Their Applications in Antiyellowing and Resistance of Photodegradation

“…22−24 But the drawbacks such as easy migration into the environment due to their low molecular weight and incompatibility with polymers, especially toxicity, cause a potential huge threat to humans or animals by natural circulation. 25,26 To solve the toxicity problem of organic polymer UV absorbers, the construction of nontoxic poly(vinyl chloride) (PVC)-UV absorber has been achieved successfully, and it shows outstanding resistance to UV photoaging for PVC, but this technical route is difficult to promote due to the complexity of the process and the high cost. 27 Very regrettably, there are few water-soluble UV absorbers, even though there exists great market demand in waterborne coatings and sunscreen cosmetics.…”

Construction of Nontoxic Polymeric UV-Absorber with Great Resistance to UV-Photoaging

“…The benzophenone classes have advantages of cheap price, simple processing of industrial production, excellent photostability, less discoloring, and good water resistance etc., which make them popular in PVC outdoor applications 11 . However, benzophenone UV-absorbers are usually easy to separate out or be extracted by solvents due to its low molecular weight and incompatibility with PVC macromolecules 12 13 . This disadvantage not only influences the durability of its effectiveness but can cause pollution to the environment because most of benzophenone UV-absorbers are toxic to humans or animals 14 15 .…”

“…Nowadays, most studies on UV-absorbers for PVC are as followings 16 17 18 : (1) increasing the molecular weight of UV-absorbers; (2) introducing UV-absorber moieties covalently through random copolymerization; (3) intra-molecular multifunction of UV-absorbers. Nevertheless, these modifications also lead to some new problems 12 19 : the light stability of UV absorbers with relatively high molecular weight (still not comparable to PVC matrix) is usually not good enough as low molecular weight species due to poor dispersion in polymer matrix; the copolymerization with UV absorbers will inevitably affect the material properties of polymers; intramolecular multifunction often has a bad effect on material application in thermal stability, compatibility, color and so on. Thus, there is still a strong demand from industrial application to develop a new approach for stabilizing PVC against photoaging without the separation of UV-absorber.…”