亚磷酸酯对聚氯乙烯的稳定作用

聚氯乙烯(PVC)树脂在加工应用过程中常常要添加稳定剂、润滑剂、增塑剂及各种充填料等。这些添加剂是成型工艺的需要或制品性能的要求。PVC树脂在加工过程中受到热、光、氧作用会变色,甚至分解,合理设计配方很重要。加入少量亚磷酸酯将大大提高稳定效果。1 亚磷酸酯在PVC及其共聚物中的稳定机理亚磷酸酯可用作各种PVC配方的稳定剂是由于其中磷原子有未共用电子对和未     

亚磷酸酯在聚丙烯中的热氧稳定作用

通过聚丙烯树脂中工稳定性及聚丙烯薄片烘箱老化试验，比较了烷基亚磷酸酯ＷＥＳＴＯＮ６１９与芳基亚磷酸酯ＩＲＧＡＴＯＳ１６８对ＰＰ热氧稳定性作用的影响，结果表明：在与酚类抗氧剂１０１０并用时，ＷＥＳＴＯＮ６１９对ＰＰ的长期热氧稳定性有明显的协同效应，而ＩＲＧＡＴＯＳ１６８则可有效地抑制ＰＰ的热氧降解。     

无酚法二硬脂基季戊四醇亚磷酸酯的研制

介绍了一种新型抗氧剂——二硬脂基季戊四醇亚磷酸酯的性能及研制，样品经有关单位应用，达到国外同类产品的质量要求。     

多元醇对聚氯乙烯热稳定作用的影响

采用静态热老化法、动态热老化法、刚果红变色法、红外光谱分析(FT-IR)、热失重分析(TGA)等现代仪器分析方法,评价了多元醇单独使用以及与硬脂酸锌(ZnSt2)复配使用时,对聚氯乙烯(PVC)的热稳定作用,并研究其协同作用机理。结果表明,多元醇单独使用时,能吸收聚氯乙烯受热分解产生的氯化氢(HCl),改善PVC的初期着色性,随着多元醇含量的增加,PVC热稳定时间延长。当硬脂酸锌与山梨糖醇复配含量为(0.7/0.4)份时,PVC的静态热稳定时间从15 min增加到21 min,热失重第一阶段试样残留量由44.97%增加到49.78%,表明山梨糖醇与ZnSt2复配能与降解产生的ZnCl2络合,缓解"锌烧"现象,改善了PVC的长期热稳定性。     

抗氧剂十六烷基季戊四醇双亚磷酸酯的合成

本文以季戊四醇、三氯化磷、十六醇等为原料合成了抗氧剂十六烷基季戊四醇双亚磷酸酯，探索了温度、反应时间、催化剂、原料配比等反应条件对产率的影响，并用元素分析、红外光谱等方法对该合成产物的结构进行了表征。     

无酚法双十八酯基季戊四醇亚磷酸酯的研制

介绍了抗氧剂—双十八酯基季戊四醇亚磷酸酯的合成方法,讨论了反应温度、反应时间、盐酸吸收剂及原料配比等因素对反应的影响。     

羧酸酯稀土对聚氯乙烯的加工热稳定作用研究

本文通过静态热稳定和动态热稳定方法比较了羧酸酯稀土(CERES)与有机硫醇锡对聚氯乙烯(PVC)的加工热稳定作用,发现它们的稳定效果相当。并依照质谱分析结果探索了 CERES 对 PVC 的热稳定机理。     

稀土对聚氯乙烯（PVC）的热稳定作用

稀土对聚氯乙烯（ＰＶＣ）的热稳定作用李昕ＴＨＥＲＭＡＬＳＴＡＢＩＬＩＺＡＴＩＯＮＯＦＲＡＲＥＥＡＲＴＨＳＯＮＰＶＣ１前言聚氯乙烯（ＰＶＣ）是世界五大通用塑料之一，１９８７年，ＦＶＣ树脂产量约６００ｋｔ，制成品约８００ｋｔ，１９９０年ＰＶＣ树脂产量将近...     

季戊四醇双亚磷酸酯类抗氧剂852的合成研究

以2,4-二枯基酚、季戊四醇、三氯化磷为基本原料合成了抗氧剂852,即二(2,4-二枯基苯基)季戊四醇双亚磷酸酯。重点讨论了反应溶剂、催化剂、物料配比、反应温度、反应时间和结晶溶剂对产品收率的影响,筛选出了最佳的合成工艺条件为:物料摩尔配比η(2,4-二枯基酚)∶η(三氯化磷)∶η(季戊四醇)为2.00∶2.18∶1.00,第一步反应温度60℃,反应4h,第二步反应110℃,反应6h,反应收率为78%。     

抗氧剂二硬脂基季戊四醇二亚磷酸酯的合成新工艺

本文以季戊四醇、亚磷酸三乙酯和十八醇为原料，在实验室合成了二硬脂基季戊四醇二亚磷酸酯。考查了反应温度、反应时间、催化剂及物料配比对产品收率的影响．实验结果表明，整个工艺过程可分为两步：合成季戊四醇二亚磷酸酯中间体时，最佳的工艺条件为：亚磷酸三乙酯、季戊四醇的摩尔比为2．05：1，催化剂的用量为季戊四醇量的3％，反应温度为13℃，时间为2．5h；在二硬脂基季戊四醇二亚磷酸酯的合成时，十八醇与中间体季戊四醇二亚磷酸酯的摩尔比为2．05：1，反应温度为16℃，时间3h。合成的产品中无酚无三废产生，产品元素分析及红外光谱与目的产物相一致。     

Study on the Thermal Stability and Stabilization Mechanism of a Novel Thermal Stabilizer for Rigid Poly (Vinyl Chloride)

A novel thermal stabilizer for rigid poly (vinyl chloride) has been examined. Its high stabilizing efficiency is detected by the extent of discoloration and the mass loss rate of the degraded samples when compared with some of reference stabilizers. A higher stabilizing efficiency is produced as the novel thermal stabilizer is mixed with different co-stabilizers. The study results for thermo oxidative stability of the degraded samples with novel thermal stabilizer have shown that the novel thermal stabilizer can prevent or delay the thermal oxidative degradation of PVC. A probable stabilization mechanism for the novel thermal stabilizer has been proposed.     

聚L-乳酸的热性能研究

为了了解聚L-乳酸(PLLA)自身结构特点,更好地控制其成型加工过程,研究了PLLA的非等温结晶行为、熔融行为和热失重过程。结果表明:降温速率对PLLA的非等温结晶过程具有显著影响,在1℃/min的降温速率下,PLLA的结晶起始温度为121℃,结晶焓为3.363 J/g;PLLA的熔融双峰遵循熔融-再结晶的机理;PLLA热分解温度在300℃左右,且随升温速率的增加而增大。     

Thermal degradation kinetics and mechanisms of PMEPP and MEPP/MMA copolymer

In this study, 2-methacryloxyethyl phenyl phosphate (MEPP), a phosphorus-containing flame retardant, was synthesised via the esterification of phenyl dichlorophosphate (PDCP) with 2-hydroxyethyl ethylene methacrylate (HEMA), followed by hydrolysis. A two-stage bulk polymerisation process prepared MEPP/methyl methacrylate (MEPP/MMA) copolymers containing various amounts of MEPP. The condensed-phase and volatized products produced at various temperatures during the thermal degradation of MEPP/MMA copolymer were monitored by Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis with Fourier transform infrared spectroscopy (TGA/FT-IR). Finally, we propose the possible mechanisms for the thermal degradation of MEPP/MMA copolymer according to the analytical results of the condensed-phase and volatilized products.     

Thermal and mechanical properties of silane-crosslinked poly(vinylchloride)

A comparative study has been made of the crosslinking of plasticized PVC by grafting of γ-aminopropyltriethoxysilane (ASi) and sodium γ-mercaptopropyltrimethoxysilane (NaMSi) during processing. The influence of type of reagent and concentration, and the rheological behavior were investigated to obtain a crosslinked material with improved mechanical properties and good thermal stability. Depending on the reagent concentration, different gel contents, ranging from 0–100%, were obtained with both reagents. For all crosslinked systems the mechanical properties above T_g were improved. In the case of ASi-crosslinked PVC, the thermal stability deteriorated significantly but, for NaMSi-crosslinked PVC, thermal stability remains close to that of raw PVC, and the separation of the grafting and crosslinking processes is more viable in this case. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 865–872, 1998     

Mechanical and Thermal Properties of Poly(Phthalazinone Ether Sulfone)/Poly(Ether Sulfone) Blends

The mechanical and thermal properties of poly(phthalazinone ether sulfone) (PPES)/poly(aryl ether sulfone) (PES) blends prepared by melt-mixing were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The dynamic mechanical thermal analysis results show that the incorporated PES has a large influence on the heat stability of PPES. The DMTA results display that the blends with a single glass transition temperature, which increases with increasing PPES content, indicates that PPES and PES are completely miscible over the studied composition range. The thermodegradative behavior of PPES/PES blends was used to analyze their thermal stability. The Friedman technique was used to determine the kinetic parameters (i.e., the apparent activation energy and order of reaction of the degradation process). The results indicate that the presence of the PES component influences the thermal stability of the PPES. On the basis of the kinetic data derived from Friedman' approach, the lifetime estimates for pure PPES, pure PES, and the blends generated from the weight loss of 5% were constructed.     

Effects of Carbon Fillers on Crystallization Properties and Thermal Conductivity of Poly(phenylene sulfide)

Differential scanning calorimetry and polarized optical microscopy methods were used to investigate the crystallization behavior and isothermal crystallization kinetics of poly(phenylene sulfide) (PPS)/carbon nanotube (CNT) and PPS/CNT/carbon fiber (CF) composites. In this article, the influences of CNT and CF on PPS crystallization behavior are explained. The thermal conductivity properties of composites were studied using the laser flash method. The results show that CNT increased crystallization temperature and rate and thermal conductivity greatly improved at 8 wt.% CNT content. In addition, the crystallization and thermal performance of PPS are significantly improved via synergistic effects of CNT and CF in the composites.     

Preparation and Characterization of Poly(benzimidazole-amide)/ZnO Nanocomposites Using Silane Coupling Agent

Some novel nanocompoites were fabricated via zinc oxide (ZnO) nanoparticles which was modified by 3-aminopropyltriethoxylsilane (KH550) as a coupling agent. Poly(benzimidazole-amide) (PBIA) was synthesized via polymerization reaction of 1,3-bis(5-amino-1H-benzimidazol-2-yl)benzene (3a) with isophthaloyl chloride (4b) and used as a polymer matrix. PBIA/ZnO nanocompoites were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). FE-SEM and TEM analysis showed that the modified ZnO nanoparticles were homogeneously dispersed in polymer matrix. In addition, thermogravimetric analysis (TGA) data indicated an enhancement of thermal stability of nanocomposite compared with the pure polymer.     

聚对苯二甲酰十碳二胺的制备和热稳定性研究

以对苯二甲酸和癸二胺为原料,经成盐、预聚合和固相聚合三个步骤合成了新型长碳链和较高分子量的半芳香尼龙聚对苯二甲酰十碳二胺（PA10T）。用TG-DTG方法研究了PA10T的热降解和热降解动力学,结果表明,PAIOT的热分解为一步降解,其起始平衡降解温度为435．3℃,终止平衡降解温度为470．7℃,最大降解速率时平衡降解温度为459．5℃。通过微分法和积分法计算出PA10T的热分解活化能分别为274．4kJmol^-1和263．96～290．37kJmol^-1之间,其耐热性能优于脂肪族尼龙。     

Thermal stability of poly(trimethylene terephthalate)

The first-order thermal degradation rates of poly(trimethylene terephthalate) [PTT] at 240-280 °C under non-oxidative conditions have been determined from the increase in allyl endgroups (¹H NMR) which closely match the rates determined from the decrease in molecular weight (intrinsic viscosity). Consequently, the predominant thermal degradation mechanism of PTT is consistent with concerted, electrocyclic oxo retro-ene chain cleavage under conditions pertinent to viable polymerization processes and efficient downstream extrusion and spinning into fiber. Although catalysts, additives and other reaction variables can influence the thermo-oxidative stability of polyesters including PTT, these factors have been found to have little or no effect on PTT thermal degradation rates under non-oxidative environments. The thermal stability of poly(butylene terephthalate) [PBT] has also been determined from butenyl endgroups (NMR) and molecular weight (IV). The activation energies (E_a) for both PTT and PBT thermal chain cleavage are similar to the reported E_as for poly(ethylene terephthalate) [PET] degradation, which is further supported by semi-empirical molecular orbital calculations on model compounds. However, both PTT and PBT undergo molecular weight decrease faster than PET. The apparent slower chain cleavage of PET is attributed to the contribution of productive chain propagation reactions due to unstable vinyl endgroups which alters the equilibrium stoichiometry compared to the relatively stable endgroups of PTT and PBT.     

高聚合度聚氯乙烯的光热稳定性

主要研究了高聚合度聚氯乙烯（HPVC）的热稳定性和热分解过程以及光老化对HPVC性能的影响。结果表明，聚合度越高，树脂的热稳定性越好，HPVC的耐光老化性能明显优于普通聚合度聚氯乙烯（PVC）。