【正文】 研究中使用的有機錫穩(wěn)定劑(TIN41)產自Kimfor Chemical Ltd。再循環(huán)超級市場托盤有很好的沖擊性能，主要是因為托盤公式中有高的抗沖改性劑。用于電纜和電線隔離材料的聚氯乙烯可以被溶解，并被分離出來。調查的結果表明利用回收材料制成的瓶子比用純聚氯乙烯材料制成的聚氯乙烯瓶子更容易分解。本項研究，采用5種不同組分的PVC來制作門窗型材。沒有證據(jù)表明暴露在陽光下的聚氯乙烯制品的外表面附近聚有大量的鈦白粉。金紅石型鈦白粉對可見光有很好的反射作用，并且能夠高度吸收紫外線。他們研究了使用巴比妥酸及其硫代物作為硬質PVC熱穩(wěn)定劑的可能性。其降解以自催化脫氯化氫的方式在聚合物鏈不穩(wěn)定處反應。然而，在實踐中大多數(shù)聚合物，如含有羰基或羧基或氫過氧化物的聚合物，很容易吸收290400nm范圍內的輻射而導致降解。熱和陽光都可以導致PVC的降解。波長為290400納米的紫外線所含的輻射能可以使目前聚合物中絕大多數(shù)的化學鍵斷裂。 and can reach the end points of embrittlement and total disintegration.The degradation of polymers exposed to UV, often described as photodegradation and frequently identified as photooxidation, can follow various routes. By absorbing UV radiation directly, a polymer molecule can reach a highenergy excited state where it bees unstable. If the excess energy can be dissipated in a fashion that does not affect the molecule by making it phosphoresce or fluoresce, or by converting the energy to heat that can be carried away, or by transferring the energy to another molecule, photochemical reaction does not started and thus, polymer degradation will not happen. However, such actions occur only rarely, since most polymers cannot dispose of the excitation energy without undergoing a chemical reaction that sets off a degradative process.In theory, many pure polymers should not absorb UV radiation, and thus, not be subject to photodegradation. However, in practice the most polymers contain impurities such as carbonyl or carboxy groups or hydroperoxides that readily absorb radiation in the 290–400 nm range causing them to break down. Thus, generating sites within the polymer structure where chemical reactions can be initiated and propagated by free radicals. The active groups may be unavoidably present as a result of reactions that occur during polymerization. Similarly, metallic ions are present in most polymers as residues from polymerization catalysts, or as constituents of pounding additives such as heat stabilizers, antioxidants, colorants, fillers and others. The metal ions are highly receptive to the absorption of UV radiation, and are efficient in transferring the absorbed energy to the polymer molecules around them, thus, they act as photosensitizers and can promote degradation at the same time that they perform their desired functions.Another contributor to photodegradation of polymers is oxygen, which helps any free radicals that may be liberated by the UV to initiate and propagate oxidation of the polymer, hence, the term photooxidation.Polyvinyl chloride suffers from poor heat stability. Its degradation occurs by autocatalytic dehydrochlorination initiated at the labile sites in the polymer chains. This leads to severe discoloration and loss of mechanical properties. The dehydrochlorination most probably proceeds by a chain mechanism involving radical intermediates. Various defect sites in PVC are branching.Inorganic and organic thermal stabilizers are monly added to protect the polymer from heat degradation. Among the most widely used ultraviolet stabilizers is titanium dioxide pigment. Filling a polyvinyl chloride position with this pigment substantially reduces the effective depth of penetration of ultraviolet light into the surface of an article formed from such a position.Mohamed et al. pointed out that barbituric acid and thiobarbituric acid are nontoxic organics, thermally stable materials of high melting point. Both contain active methylene groups, and can act as Hdonor through their enolic hydrogen groups, which can intervene with the radical species derived from the thermal degradation of PVC. They investigated the possibility of using barbituric acid and its thioanalogue as thermal stabilizers for rigid PVC.The effective stabilization often requires a bination of antioxidant system in which plementary overlap of different mechanistic pathways involved. This act often referred to as synergism, is the motivation for the use of admixing position of dibutyltin maleate and trinitro and its ester homologues. The stabilization agents of dibutyltin maleate and trinitro esters could retard somewhat the photodegradation of PVC. It is ho