Synthesis of new polymeric stabilizers for polymers

A monomeric stabilizer (M), 2,2,6,6‐tetramethyl‐4‐piperidinyl(6‐methacryloyl amino)hexyl carbamate‐1, was synthesized by a two‐step controlled isocyanation in which methacrylic acid (MAA) reacted in the first step with hexamethylene diisocyanate (HMDI) at a 1 : 1 mol ratio to form an addition product containing one isocyanate group and one unsaturated double bond. In the second step, this product was reacted with 2,2,6,6‐tetramethyl‐4‐piperidinol (TMP) in a 1 : 1 mol ratio at 80°C in the presence of a catalyst dibutyltin dilaurate (DBTDL) to yield M. A new polymeric stabilizer, copolymer P1, was produced from M with methyl methacrylate (MMA) and another copolymer P2 was produced by reacting M with 2‐hydroxy‐4‐benzophenonyl allyl carbamate (AI‐DHBP). Azobisisobutylonitrile (AIBN) was used as an initiator. Their structures, thermal stability, extraction resistance, solubility in organic solvents, and stabilizing effectiveness against photooxidation and thermal oxidation of polypropylene (PP) were characterized by IR, NMR, TGA, and elemental analysis. The results show that both the monomeric and the polymeric stabilizers possess a stabilizing action for protecting PP against photooxidation and thermal oxidation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 403–411, 2000     

Synthesis of new polymeric hindered amine light stabilizers: Performance evaluation in styrenic polymers

Polymeric hindered amine light stabilizers (HALSs), in which the HALS functionality was attached to the terminal isocyanate chain end of poly(styryl‐co‐styryl isocyanate), were synthesized by a two‐step process. First, cinnamoyl azide was prepared and copolymerized with styrene by a free‐radical copolymerization method. Polymeric low‐molecular‐weight and high‐molecular‐weight 2,2,6,6‐tetramethyl‐4‐pipridinol‐graft‐poly(styryl‐co‐styryl isocyanate) and 4‐amino‐2,2,6,6‐tetramethyl piperidine‐graft‐poly(styryl‐co‐styryl isocyanate) were synthesized by a grafting method. The photodegradation and stabilization of different grades of high‐impact polystyrene (HIPS) were studied at 55°C in air at different time intervals, and the photostabilizing efficiency of polymeric HALSs was compared with conventional light stabilizers, such as 2,2,6,6‐tetramethyl‐4‐pipridinol and bis(2,2,6,6‐tetramethyl‐4‐piperidinyl)sebacate. Polymeric HALSs showed significant improvements in the photostabilization of HIPS. The solubility and diffusion coefficient of polymeric HALSs were studied. The morphological changes in HIPS caused by photooxidation were also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1126–1138, 2003     

In situ detection of hindered amine stabilizer consumption in polymer through oxidation by indirect electron spin resonance

The stabilization mechanisms of hindered amine stabilizers (HAS) involve various oxidation products of the piperidine structure. Thus, we propose a novel method, based on electron spin resonance (ESR) spectroscopy, to check in situ the consumption of the total piperidyl species (intact HAS and all of its byproducts) in polypropylene (PP) films through photooxidation. First, the concentration of nitroxyl radicals produced upon irradiation in stabilized PP has been measured by direct ESR analysis. Then, the changes of concentration of the overall stabilizing species have been detected by indirect ESR, after conversion of the overall HAS derivatives into nitroxyl-free radicals by exposure of photooxidized PP to peracetic acid vapor at room temperature. Results were compared with those obtained by the conventional Fourier transform infrared method in the particular case of [2,2,6,6-tetramethyl piperidinyl]sebacate, and the reliability of both techniques was discussed. Thus, we assume that indirect ESR experiments consist of a easy, accurate, and very sensitive method to monitor the time evolution of a low-molecular weight HAS–NH concentration in PP upon photooxidation. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1107–1114, 1998     

Water‐Soluble Nitric‐Oxide‐Releasing Acetylsalicylic Acid (ASA) Prodrugs

A series of water‐soluble (benzoyloxy)methyl esters of acetylsalicylic acid (ASA), commonly known as aspirin, are described. The new derivatives each have alkyl chains containing a nitric oxide (NO)‐releasing nitrooxy group and a solubilizing moiety bonded to the benzoyl ring. The compounds were synthesized and evaluated as ASA prodrugs. After conversion to the appropriate salt, most of the derivatives are solid at room temperature and all possess good water solubility. They are quite stable in acid solution (pH 1) and less stable at physiological pH. In human serum, these compounds are immediately metabolized by esterases, producing a mixture of ASA, salicylic acid (SA), and of the related NO‐donor benzoic acids, along with other minor products. Due to ASA release, the prodrugs are capable of inhibiting collagen‐induced platelet aggregation of human platelet‐rich plasma. Simple NO‐donor benzoic acids 3‐hydroxy‐4‐(3‐nitrooxypropoxy)benzoic acid ( 28 ) and 3‐(morpholin‐4‐ylmethyl)‐4‐[3‐(nitrooxy)propoxy]benzoic acid ( 48 ) were also studied as representative models of the whole class of benzoic acids formed following metabolism of the prodrugs in serum. These simplified derivatives did not trigger antiaggregatory activity when tested at 300 μM . Only 28 displays quite potent NO‐dependent vasodilatatory action. Further in vivo evaluation of two selected prodrugs, {[2‐(acetyloxy)benzoyl]oxy}methyl‐3‐[(3‐[aminopropanoyl)oxy]‐4‐[3‐(nitrooxy)propoxy]benzoate?HCl ( 38 ) and {[2‐(acetyloxy)benzoyl]oxy}methyl 3‐(morpholin‐4‐ylmethyl)‐4‐[3‐(nitrooxy)propoxy]benzoate oxalate ( 49 ), revealed that their anti‐inflammatory activities are similar to that of ASA when tested in the carrageenan‐induced paw edema assay in rats. The gastrotoxicity of the two prodrugs was also determined to be lower than that of ASA in a lesion model in rats. Taken together, these results indicated that these NO‐donor ASA prodrugs warrant further investigation for clinical application.     

Oriented distribution structure,interaction, and performance of thermoplastic polyurethane/selective hindered amine hybrids

By employing the melt blending method, selective hindered amines were oriented to disperse in the hard phase of thermoplastic polyurethane (TPU). The microstructure and performance of organic hybrids consisting of TPU and poly‐[(1‐hydroxyethyl ‐2,2,6,6‐ tetramethyl‐ 4‐hydroxyl piperidine)]‐glycolsuccinate (GW‐622) and poly‐{[6‐(1,1,3,3‐tetramethylbutyl) ‐imino]‐[1,3,5‐triazine‐2,4‐ dimethyl] [2‐(2,2,6,6‐ tetramethyl piperidinyl)‐ imino]‐cyclohexane‐[4‐(2,2,6,6‐tetramethyl piperidinyl)‐imino]} (GW‐944) were investigated by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), scanning electric microscopy (SEM), and tensile measurement. The neat TPU matrix displayed only one glass transition peak in the DMA curve, whereas the TPU/GW‐622 hybrids exhibited two overlapping loss peaks, and the TPU/GW‐944 hybrids demonstrated two separated relaxation peaks. The second excited relaxation peak of the hybrids was attributed to the oriented distribution of hindered amine in TPU and strong intermolecular interactions between the hindered amine and the hard segments of TPU. The complex and interesting evolution in structure and properties of the hybrids with hindered amine incorporation was interpreted. The loss peak areas (TA) of the hybrids increased greatly, and the high temperature damping properties was expected to improve. This kind of novel hybrid presented a promising future as high performance damping material. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of antiaging agents on the outdoor natural weathering of bamboo powder/polypropylene foamed composites

The effect of outdoor natural weathering on the properties of injection molded 33 wt% bamboo powder (BP)/polypropylene (PP) foamed composites with and without the antioxidant and hindered amine light stabilizers (HALS) were investigated. The composites containing the antiaging agents had higher color stability, slightly greater retentions of flexural modulus, tensile and notched impact strengths, higher creep resistance, and better rheological stability than the reference composite. The antiaging agents of pentaerythritol tetrakis(3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionate) and poly‐(n‐hydroxyethyl‐2,2,6,6‐tetramethyl‐4‐hydroxy‐piperidyl succinate) had more beneficial effect than n‐octadecyl‐β‐(4‐hydroxy‐3,5‐di‐tert‐butyl‐phenyl)‐propionate and bis(2,2,6,6‐tetramethyl‐4‐piperidinyl)sebacate. After 12 months of exposure, △E^* decreased from 22.8 of the reference composite to 9.9 of the composite with the antiaging agents. Rheological behavior results indicated that the storage modulus, complex viscosity, and non‐Newtonian fluid index of composites containing the antiaging agents were slightly increased. Natural weathering caused less decreases in the storage and loss moduli, crossover modulus, relaxation time, and average molecular weight for composites containing the antiaging agents than those for the reference composite. Environmental scanning electron microscopy (ESEM) observation confirmed the improved surface durability for composites containing the antiaging agents. J. VINYL ADDIT. TECHNOL., 22:311–319, 2016. © 2014 Society of Plastics Engineers     

Synthesis and properties of some fluorescent 1,8‐naphthalimide derivatives and their copolymers with methyl methacrylate

Six new fluorescent derivatives of 1,8‐naphthalimide were synthesized. Three were dyes, and three were fluorescent whitening agents (FWAs) containing a tetramethylpiperidine (TMP) stabilizer fragment. The FWAs were obtained under phase‐transfer catalysis conditions. Five of the compounds were copolymerized with methyl methacrylate, so copolymers with an intense color and/or fluorescence stable against solvents were obtained. The chemical bonding of the synthesized monomers in the polymers was confirmed spectrophotometrically. The participation of the monomer compounds did not significantly affect the process of copolymerization or the molecular masses of the obtained copolymers. The quantity of chemically bonded naphthalimide monomer in the copolymers was determined to be over 60%. The spectral properties of the compounds and their photostability in solution and in the copolymers were studied. The influence of the compounds on the photostability of the copolymers was determined. The compounds, especially those containing a stabilizer (TMP) fragment in their molecules, showed a positive stabilizing effect on the photodegradation of poly(methyl methacrylate). Polyamide fabrics with 2‐allyl‐6‐hydrazino‐benzo[de]isoquinoline‐1,3‐dione, 2‐allyl‐6‐(2‐amino‐ethylamino)‐benzo[de]isoquinoline‐1,3‐dione, and 2‐chloro‐N′‐(2‐methyl)‐1,3‐dioxo‐2,3‐dihydro‐1H‐benzo[de] isoquinoline‐6‐yl) acetohydrazide were dyed, and materials with an intense yellow color and fluorescence were obtained. Cotton fabrics were whitened with 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐methoxy‐benzo[de]isoquinoline‐1,3‐dione, 2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐6‐allyloxybenzo[de]isoquinoline‐1, 3‐dione, and 2‐[2‐(2,2,6,6‐tetramethyl‐piperidin‐4‐yl)‐1,3‐dioxo‐2,3‐dihidro‐1H benzo [de]isoquinoline‐6‐oxy]ethyl‐2‐methacrylate, and materials with bright whiteness and intense bluish fluorescence were obtained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Characterization of networks from photoreactive copolymers: an attempt to correlate chemical composition to network structure

The photoreactivity of polystyrene bearing photoreactive benzil (BZ) pendant groups was studied. Upon irradiation (λ > 370 nm), BZ groups were transformed to benzoyl peroxide (BP) groups that caused crosslinking of the polymer upon heating. The main goal of this study was to characterize the final network. Melt viscoelasticity is a powerful method to assess some specific parameters of a crosslinking process (gel point, crosslink density). Classical methods based on low‐frequency slope variations, such as the Winter and Chambon method, were successfully applied. A good correlation was established between the content of BP groups after the first irradiation and the final density of the network after crosslinking. It was determined that at least two peroxidic species (BP groups) per macromolecular chain are necessary to reach the gel point. The concentration of BZ groups and their conversion into BP groups are the factors supporting a denser network. Copyright © 2010 Society of Chemical Industry     

A replicated investigation of nitroxide‐mediated radical polymerization of styrene over a range of reaction conditions

A comprehensive experimental investigation of nitroxide‐mediated radical polymerization (NMRP) of styrene using 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) as controller is presented. Polymerizations with a bimolecular initiator (benzoyl peroxide; BPO) were carried out at 120 and 130°C, with TEMPO/BPO molar ratios ranging from 0.9 to 1.5. Results indicate that increasing temperature increases the rate of polymerization while the decrease in molecular weights is only slight. It was also observed that increasing the ratio of TEMPO/BPO decreased both the rate of polymerization and molecular weights. Probably for the first time in the history of such investigations, the paper contains a comprehensive database, appropriate for parameter estimation in aid of future modelling studies, since it comes from a systematic data collection containing independent replication.     

Triple‐faced polypropylene: Fire retardant,thermally stable,and antioxidative

A halogen‐free nitrogen‐rich additive was used to make polypropylene (PP) prepared for three different missions: fire retardancy, thermal stability, and antioxidative properties. The prepared additive was composed of a cyclodextrin, a nanohydroxyapatite, and a poly[[6‐[(1,1,3,3,‐tetramethylbutyl)amino]‐1,3,5‐triazine‐2,4‐diyl][(2,2,6,6‐tetramethyl‐4‐piperidinyl)imino]‐1,6‐hexanediyl[2,2,6,6‐tetramethyl‐4‐piperidinyl)imino] (SABO®STAB) integrated into a unique molecule, namely, BSDH. Fire retardancy performance of BSDH in PP was compared with that of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) commercially available additive in terms of cone calorimeter results. Thermal stabilities of PP/BSDH and PP/DOPO composites were compared by changes observed in pyrolysis activation energy values measured in thermogravimetric analysis under nitrogen atmosphere at various heating rates. Flame retardancy of PP/BSDH composite was reflected in a drop in the peak of Heat Release Rate by ca. 31% with respect to neat PP. Very interestingly, the results show that BSDH additive retarded thermal oxidation of PP macromolecular chains when compared with DOPO commercially available flame retardant, as signaled by a rise in oxidation induction time value as well as an increased early‐stage activation energy needed for thermal decomposition of PP in the presence of BSDH. J. VINYL ADDIT. TECHNOL., 25:366–376, 2019. © 2019 Society of Plastics Engineers     

The effect of grafted TMPM on the radiation resistance of polypropylene

The γ‐radiation–induced graft copolymerization of 2,2,6,6‐tetramethyl‐4‐piperidinyl methacrylate (TMPM) onto polypropylene (PP) was investigated using a simultaneous‐irradiation technique. The effects of solvents, atmospheres, dose, and monomer concentration on the percent of grafting were studied. The grafted TMPM showed better thermal stability, solvent extraction resistance, and compatibility with PP than monomeric TMPM or polymeric PTMPM. The stabilizing effectiveness of grafted TMPM on the radiation resistance of PP was found to be better than that of monomeric TMPM. The combination of grafted TMPM and low molecular weight hindered amine light stabilizers showed higher stabilizing effectiveness. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2150–2157, 1999     

Synthesis of poly(vinyl acetate)‐graft‐polystyrene and application to preparation of porous membranes

Poly(vinyl acetate)–TEMPO (PVAc–TEMPO) macroinitiators were synthesized by bulk polymerization of vinyl acetate in the presence of benzoyl peroxide (BPO) followed by termination with 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO). Radicals were mainly transferred to the acetoxy methyl groups in PVAc during the polymerization. The PVAc–TEMPO macroinitiators had several TEMPO‐dormant sites and styrene bulk polymerization with the macroinitiators produced poly(vinyl acetate)‐graft‐polystyrene (PVAc‐g‐PS). All the TEMPO‐dormant sites of PVAc–TEMPO macroinitiators participated in the styrene polymerization with almost equal reactivity. Methanolysis of PVAc‐g‐PS broke the PS branches apart from the PVAc backbone chains. Hydrophobic or hydrophilic porous membranes with controlled pore size could be prepared by removing the PVAc domains or the PS domains from the graft copolymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1658–1667, 2001     

受阻胺类光稳定剂GW-944的合成

以三聚氯氰、叔辛胺和N,N′ 二(2,2,6,6 四甲基 4 哌啶基) 1,6 己二胺为原料用三步法合成出受阻胺类光稳定剂GW-944。三聚氯氰与叔辛胺在5℃下反应3h,得到中间体Ⅰ,收率71 4%;Ⅰ与N,N′ 二(2,2,6,6 四甲基 4 哌啶基) 1,6 己二胺于65℃下反应5h,得到中间体Ⅱ,收率90 8%;Ⅱ与N,N′ 二(2,2,6,6 四甲基 4 哌啶基) 1,6 己二胺在高压釜中于170～180℃下反应8h,得到目标产物GW-944。在本文提出的最佳反应条件下,所得到的GW-944的平均相对分子质量大于2000,在425和450nm下的透光率均大于95%。     

Synthesis of polyethylene‐graft‐poly(styrene‐co‐maleic anhydride) and its compatibilizing effects on polyethylene/starch blends

Low density polyethylene (LDPE) was reacted with benzoyl peroxide (BPO) and 2,2,6,6‐tetramethyl‐l‐piperidinyloxy (TEMPO) to prepare a latent macroinitiator, PE–TEMPO. Little polymer was synthesized when maleic anhydride (MAH) was bulk polymerized in the presence of the PE–TEMPO. However, addition of styrene accelerated the polymerization rate and PE‐grafted‐poly(styrene‐co‐maleic anhyride) [PE‐g‐P(ST‐co‐MAH)] was produced to a high yield. Chemical reaction between MAH units and hydroxyl groups of starch was nearly undetectable in the PE/PE‐g‐P(ST‐co‐MAH)/starch blend system, and the tensile properties of the blend were not enhanced significantly. However, addition of tetrabutyl titanate (TNBT) during the blending procedure improved the tensile properties significantly through an increased interfacial adhesion between the components in the blend system. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2434–2438, 2003     

Different Acylating Agents in the Synthesis of Aromatic Ketones on Sulfated Zirconia

Sulfated zirconia (SZ) has been used as a heterogeneous catalyst in the synthesis of aromatic ketones. A number of carboxylic anhydrides and acid chlorides proved to be appropriate acylating agents in the reaction with anisole and chlorobenzene. The rate of anisole acylation was found to be dependent on the type of acylating agent used. Thus, acetic anhydride and benzoic anhydride reacted faster on SZ with anisole than benzoyl chloride. Successful SZ-catalyzed acylations of chlorobenzene were limited to acceptor substituted benzoyl chlorides as acylating agents. Acetic anhydride and benzoic anhydride did not react with chlorobenzene in the presence of SZ.     

Exploitation of the complex chemistry of hindered amine stabilizers in effective plastics stabilization

Hindered amine stabilizers (HAS) remain a prominent class of stabilizers having a fortunate development with continuous interest in shaping the future properties of plastics: increase in polymer durability, application extension, reaching new effects. Commercial tests provided much information. Insufficient mechanistic interpretations of the complex effects of environmental factors (harshness of testing, penetration of radiation and oxygen, superposition of temperature, atmospheric impurities) and those of the microenvironment (morphology of the polymer matrix, physical relations of HAS–polymer, interference between HAS and other additives) are a drawback. Model experiments complement commercial studies and explain some phenomena. A careful transfer of information from model experiments must be done to avoid misinterpretation of mechanisms, particularly of the HAS regenerative cycle. A critical analysis of primary steps of the HAS activity mechanism in the polymer matrix based on HAS‐related primary nitroxides, formation of their stationary concentration and concentration gradients influenced by polymer morphology, spatial competition between autoreactions, and oxidation of polymer‐developed alkyl radicals and their scavenging by nitroxides (the key process of HAS efficiency) is outlined. Cyclic regeneration of nitroxides affected by the structure of the amino moiety in the HAS molecule, influence of acid environment, atmospheric ozone or singlet oxygen, cooperative mixtures of HAS with UV absorbers, combinations with additives increasing the thermal stabilization effect and improving color retention, assessment of the heat stabilization performance of HAS by proper testing, and influence of the molecular weight of HAS are mentioned together with examples of the chemical consumption of HAS in the final phases of their lifetime. lifetime. J. VINYL ADDIT. TECHNOL., 13:119–132, 2007. © 2007 Society of Plastics Engineers     

Polymer‐Supported Bisacetoxybromate(I) Anion –‐An Efficient Co‐Oxidant in the TEMPO‐Mediated Oxidation of Primary and Secondary Alcohols

A polymer‐bound reagent for the efficient oxidation of primary alcohols to aldehydes and secondary alcohols to ketones in the presence of a catalytic amount of 2,2,6,6‐tetramethyl‐1‐piperidinyloxyl (TEMPO) is described. The oxidation process is particular mild and allows one to prepare aldehydes with α‐chirality without racemization. This also includes the synthesis of α‐aminoaldehydes. In most cases, work‐up of this heavy metal‐free oxidation is achieved by simple filtration followed by removal of the solvent. Insight into the role of the bromate(I) anion in the oxidation process was gained from the TEMPO‐mediated oxidation of benzaldehyde in the presence of the hypochlorite anion loaded on an anion exchange resin.     

Application of hindered piperidine amine and/or tertiary amine in the modification of polyamide 6

PA 6 resin was produced in a hydrolytic‐polymeric process in which ε‐caprolactam was polymerized in the presence of water as initiator, isophthalic acid and benzoic acid as chain regulators, by polymerizing caprolactam in the presence of 7.5% by weight of water, 0.2% by weight of isophthalic acid, 0.1% by weight of benzoic acid, each percentage being based on caprolactam. By adding hindered piperidine amine and/or tertiary amine to the polymeric system, the effects of additives on the polymer were studied. The results showed that: the addition of 0.1 ～ 0.2% additives can improve the melt stability of polyamide 6; the addition of 0.2% additives can protect mechanical properties of polyamide 6 fibers after exposure to high temperature; and the addition of 0.05 ～ 0.25% additives can increase the amino end group content of polyamide 6 and thereby increase the dyeability of polyamide fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2489–2493, 2004     

Synthesis and reactivity of functionalized alkoxyamine initiators for nitroxide‐mediated radical polymerization of styrene

The synthesis and examination of different functionalized (2,2,6,6‐tetramethyl‐1‐piperidinyloxy free radical) TEMPO‐containing alkoxyamine initiators for nitroxide‐mediated radical polymerization of styrene are reported. Initiators with ester and carbonate functional groups were synthesized by a low‐temperature radical‐abstraction reaction of the functionalized ethylbenzene in the presence of TEMPO to introduce the functional groups onto the initiating chain‐end of polystyrene. An initiator with two alkoxyamine groups symmetrically located at each end of a carbonate bond was also synthesized and used for nitroxide‐mediated styrene polymerization. Styrene polymerization using these initiators followed first‐order kinetics up to approximately 60 min at 140 °C or 30% monomer conversion. Alkoxyamines bearing an acetoxy or tert‐butylcarbonate group at the p‐position of 1‐(2,2,6,6‐tetramethyl‐1‐piperidinyloxy)ethylbenzene behave in a similar way to the unfunctionalized initiator. With an initiator containing two alkoxyamine groups, the resulting polymer molecular weight was twice that of the polymer obtained from initiators with only one alkoxyamine group, as expected from propagation from both chain‐ends. Upon hydrolysis of the carbonate bond, it was revealed that equivalent polymer chain growth occurred from each alkoxyamine site in the difunctional initiator. Copyright © 2003 Society of Chemical Industry     

Study on photostabilization in situ of reactive hindered amine light stabilizers applied to UV-curable coatings

Four monomeric reactive hindered piperidinol derivatives, such as 4-methacryloyl-1,2,2,6,6-pentamethyl-piperidinyl (MPMP), 4-acryloyl-1,2,2,6,6-pentamethyl-piperidinyl (APMP), 4-methacryloyl-2,2,6,6-tetramethyl-piperidinyl (MTMP), and 4-acryloyl-2,2,6,6-tetramethyl-piperidinyl (ATMP), were applied as reactive hindered amine light stabilizers (r-HALS) in UV-curable coatings. The effect of r-HALS on the UV-curing kinetics of the UV-curable coatings of different monomers or oligomers has been previously investigated. Polymer coatings were prepared by means of UV-curing technology; experiments were conducted manually on photoaging indoors, monitoring the Yellowness Index (YI) in the photooxidation process, and adding r-HALS. The experiments were done to review its photoprotection effect on UV-cured coatings. Subsequently, they were compared with typical commercial HALS through parallel experiments to investigate the photooxidation aging mechanism of polymer coatings, and the effective concentration was determined from the changing circumstances of YI, thus comparing their differences in photostabilizing effect in situ of the polymer coatings.