thermal stabilizer

  • 文章类型: Journal Article
    聚(L-丙交酯)-b-聚(乙二醇)-b-聚(L-丙交酯)(PLLA-PEG-PLLA)由于其优于PLLA的更大的灵活性而显示出用于生物塑料应用的前景。然而,需要进一步研究以使用适当的填料改善PLLA-PEG-PLLA的性能。这项研究使用苯基磷酸锌(PPZn)作为PLLA-PEG-PLLA的多功能填料。PPZn添加对PLLA-PEG-PLLA特性的影响,如结晶和热和机械性能,被调查了。PPZn和PLLA-PEG-PLLA之间存在良好的相相容性。PPZn的加入提高了PLLA-PEG-PLLA的结晶性能,正如冷结晶温度的消失所证明的那样,结晶度的增加,结晶温度的升高,和结晶半衰期的减少。PPZn的加入提高了PLLA-PEG-PLLA的热稳定性和耐热性。PPZn的添加还增强了PLLA-PEG-PLLA的机械性能,如极限拉应力和杨氏模量的增加所证明的。我们可以得出结论,由于其成核增强,PPZn具有用作PLLA-PEG-PLLA复合材料的多功能填料的潜力,热稳定,增强能力。
    Poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA) shows promise for use in bioplastic applications due to its greater flexibility over PLLA. However, further research is needed to improve PLLA-PEG-PLLA\'s properties with appropriate fillers. This study employed zinc phenylphosphate (PPZn) as a multi-functional filler for PLLA-PEG-PLLA. The effects of PPZn addition on PLLA-PEG-PLLA characteristics, such as crystallization and thermal and mechanical properties, were investigated. There was good phase compatibility between the PPZn and PLLA-PEG-PLLA. The addition of PPZn improved PLLA-PEG-PLLA\'s crystallization properties, as evidenced by the disappearance of the cold crystallization temperature, an increase in the crystallinity, an increase in the crystallization temperature, and a decrease in the crystallization half-time. The PLLA-PEG-PLLA\'s thermal stability and heat resistance were enhanced by the addition of PPZn. The PPZn addition also enhanced the mechanical properties of the PLLA-PEG-PLLA, as demonstrated by the rise in ultimate tensile stress and Young\'s modulus. We can conclude that the PPZn has potential for use as a multi-functional filler for the PLLA-PEG-PLLA composite due to its nucleating-enhancing, thermal-stabilizing, and reinforcing ability.
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  • 文章类型: Journal Article
    聚氯乙烯(PVC)广泛应用于各个领域,由于其热稳定性差,在加工过程中需要使用热稳定剂来增强其热稳定性。层状双氢氧化物(LDHs)被广泛认为是一种高效环保的PVC热稳定剂。研究层状双氢氧化物(LDHs)在PVC树脂中的热稳定过程,具有不同层间阴离子(CO32-,Cl-,和NO3-)物理混合并在180°C下老化。用XRD研究了不同老化时间LDHs的结构,SEM,和FT-IR。结果表明,LDHs在PVC上的热稳定过程主要有三个阶段。在第一阶段,LDH层与HCl反应,在PVC的热分解过程中释放。随后,离子交换过程发生在Cl-和层间CO32-之间,导致MgAl-Cl-LDHs的形成。最后,MgAl-Cl-LDHs层与HCl缓慢反应。在MgAl-Cl-LDHs的热稳定过程中,XRD的峰强度略有降低,并且没有新的XRD峰出现。这表明对于MgAl-Cl-LDHs仅发生第一步。LDHs的TG-DTA分析表明,LDHs与不同层间阴离子的相互作用具有以下顺序:NO3- Poly(vinyl chloride) (PVC) is widely used in various fields and requires the use of thermal stabilizers to enhance its thermal stability during processing because of its poor thermal stability. Layered double hydroxides (LDHs) are widely considered to be one kind of highly efficient and environmentally friendly PVC thermal stabilizer. To investigate the thermal stabilizing process of layered double hydroxides (LDHs) in PVC resin, PVC and MgAl-LDHs powders with different interlayer anions (CO32-, Cl-, and NO3-) were physically mixed and aged at 180 °C. The structure of LDHs at different aging times was studied using XRD, SEM, and FT-IR. The results show that the thermal stabilizing process of LDHs on PVC mainly has three stages. In the first stage, the layers of LDHs undergo a reaction with HCl, which is released during the thermal decomposition of PVC. Subsequently, the ion exchange process occurs between Cl- and interlayer CO32-, resulting in the formation of MgAl-Cl-LDHs. Finally, the layers of MgAl-Cl-LDHs react with HCl slowly. During the thermal stabilizing process of MgAl-Cl-LDHs, the peak intensity of XRD reduces slightly, and no new XRD peak emerges. It indicates that only the first step happens for MgAl-Cl-LDHs. The TG-DTA analysis of LDHs indicates that the interaction of LDHs with different interlayer anions has the following order: NO3- < CO32- < Cl-, according to the early coloring in the thermal aging test of PVC composites. The results of the thermal aging tests suggest that LDHs with a weak interaction between interlayer anions and layers can enhance the early stability of PVC significantly. Furthermore, the thermal aging test demonstrates that LDHs with high HCl absorption capacities exhibit superior long-term stabilizing effects on PVC resin. This finding provides a valuable hint for designing an LDHs/PVC resin with a novel structure and excellent thermal stability.
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  • 文章类型: Journal Article
    本文介绍了使用过甲酸对废木棉籽中的植物油进行环氧化,它是用硫酸作为催化剂原位产生的。甲酸与双键的摩尔比在0.25和1.00之间变化。通过分析FTIR和NMR光谱已经证实了反应的完成。所得的环氧化木棉籽油(EKSO)的最大环氧乙烷氧含量为2.7%,在甲酸与双键的摩尔比为0.5时实现。该研究还检查了在硬脂酸钙/锌存在下EKSO作为共稳定剂用于稳定聚氯乙烯(PVC)的潜在用途。静态和动态测试均表明,将EKSO掺入硬脂酸钙/锌体系中可显著提高PVC的热稳定性。此外,发现EKSO作为共稳定剂的有效性与环氧化大豆油(ESBO)相当。然而,EKSO的使用确实导致由于可塑性增加而导致PVC强度降低,尽管这种影响在低剂量下是最小的,并且在ESBO中也观察到。另一方面,当使用小剂量(<2phr)时,流动性有下降的趋势,但减少也不明显。总的来说,这些发现表明,EKSO可能是工业应用中PVC的有价值的共稳定剂,因为它增强了PVC的热稳定性,而不会显着损害其机械和流动性能。
    This paper describes the epoxidation of vegetable oil derived from waste kapok seeds using performic acid, which was generated in situ with sulfuric acid acting as a catalyst. The mole ratio of formic acid to double bonds varied between 0.25 and 1.00. The completion of the reaction has been verified by analyzing FTIR and NMR spectra. The resulting epoxidized kapok seed oil (EKSO) has a maximum oxirane oxygen content of 2.7%, achieved at a formic acid to double bond mole ratio of 0.5. The study has also examined the potential use of EKSO as a co-stabilizer in the presence of Ca/Zn stearate for stabilizing polyvinyl chloride (PVC). Both static and dynamic tests demonstrated that incorporating EKSO into the Ca/Zn stearate system leads to a significant increase in the thermal stability of PVC. Moreover, the effectiveness of EKSO as a co-stabilizer was found to be comparable to that of epoxidized soybean oil (ESBO). However, the use of EKSO did result in a decrease in the strength of PVC due to an increase in plasticity, although this effect was minimal at low dosages and was also observed with ESBO. On the other hand, when utilizing small doses (<2 phr), there is a tendency for flowability to decrease, but the reduction is not significant either. Overall, these findings suggest that EKSO could be a valuable co-stabilizer for PVC in industrial applications, as it enhances PVC\'s thermal stability without significantly compromising its mechanical and flow properties.
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  • 文章类型: Journal Article
    这项研究调查了表面碱度对层状双氢氧化物(LDHs)作为聚氯乙烯(PVC)热稳定剂的性能的影响。合成了具有不同表面碱度的LDHs,并使用XRD对其进行了表征,SEM,BET,和CO2-TPD。然后将LDH与硬脂酸锌和二苯甲酰甲烷组合以产生环境友好的热稳定剂并添加到PVC中。使用烘箱老化方法评价所得PVC复合材料的热稳定性。结果表明,与较高的比例(2.5、3.0和3.5)相比,较低的Mg/Al摩尔比(2.0)改善了PVC复合材料的初始白度和长期热稳定性。在LDH中用Zn代替Mg具有与降低Mg/Al比相似的效果。用5%硅烷偶联剂KH-560交联LDHs的薄层,使LDHs的表面碱度降低79%,增加色度指数,b*,PVC复合材料的热稳定性时间分别为48%和14%,分别。LDHs的结构和表面碱性与PVC复合材料的初始白度和长期热稳定性之间建立了描述性关系。
    This study investigated the impact of surface basicity on the performance of layered double hydroxides (LDHs) as heat stabilizers for polyvinyl chloride (PVC). LDHs with varying surface basicity were synthesized and characterized using XRD, SEM, BET, and CO2-TPD. The LDHs were then combined with zinc stearate and dibenzoylmethane to create an environmentally friendly heat stabilizer and added to PVC. The resulting PVC composites were evaluated for thermal stability using the oven-aging method. The results showed that a lower Mg/Al molar ratio (2.0) improved the initial whiteness and long-term thermal stability of PVC composites compared to higher ratios (2.5, 3.0, and 3.5). Replacing Mg with Zn in the LDHs had a similar effect to that of reducing the Mg/Al ratio. Crosslinking the laminae of LDHs with 5% silane coupling agent KH-560 reduced the surface basicity of LDHs by 79%, increasing the chromaticity index, b*, and thermal stability time of PVC composites by 48% and 14%, respectively. A descriptive relationship was established between the structure and surface basicity of LDHs and the initial whiteness and long-term thermal stability of PVC composites.
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  • 文章类型: Journal Article
    从棕榈脂肪酸馏出物制备羧酸钙和锌,棕榈油精炼的副产品,通过在乙醇水溶液中的复分解。两种金属羧酸盐的形成已通过红外光谱和X射线衍射分析得到证实。热重分析表明,制备的羧酸钙和锌实际上是稳定的,而它们的重量损失在393°C下为14%,在311°C下为19%,分别。还通过使用静态和动态测试研究了其混合物中的金属羧酸盐在稳定聚氯乙烯耐热方面的功效。在所研究的条件下,钙与锌的比例为4:1可提供最长的稳定时间。混合的羧酸钙/锌表现出与季戊四醇的协同作用。结果表明,棕榈脂肪酸馏出物的混合羧酸钙/锌可以有效地稳定聚氯乙烯的高温。
    Calcium and zinc carboxylates were prepared from palm fatty acid distillate, a byproduct of palm oil refining, via metathesis in aqueous ethanol. The formations of both metal carboxylates have been confirmed by infrared spectroscopy and x-ray diffraction analysis. Thermogravimetric analysis has shown that the prepared calcium and zinc carboxylates are practically stable while their weight losses are 14% at 393 °C and 19% at 311 °C, respectively. The efficacy of the metal carboxylates in their mixtures in stabilizing polyvinyl chloride against heat has also been studied by using static and dynamic tests. The calcium to zinc ratio of 4:1 has been found to give the longest stability time under the studied condition. The mixed calcium/zinc carboxylates demonstrate a synergism effect with pentaerythritol. The results reveal that mixed calcium/zinc carboxylates from palm fatty acid distillate are effective in stabilizing polyvinyl chloride against heat.
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  • 文章类型: Journal Article
    乳清酸锌(ZnOr2),这是一种新型的聚氯乙烯(PVC)稳定剂,在这项工作中通过沉淀法制备,用热重分析法(TG)测定其对PVC热稳定性的影响,刚果红测试,和变色测试。结果表明,加入ZnOr2后,PVC的热稳定性得到了积极的提高。与商业热稳定剂相比,硬脂酸锌(ZnSt2),值得注意的改进是,ZnOr2可以推迟PVC的“锌燃烧”。这主要归因于ZnOr2结构中的Or阴离子能够吸收PVC释放的HCl,取代PVC结构中不稳定的氯原子。此外,将ZnOr2与硬脂酸钙(CaSt2)以不同的质量比混合可以显着加速PVC的热稳定性。最佳性能是通过1.8:1.2的CaSt2:ZnOr2比率实现的。此外,当CaSt2/ZnOr2与其他商业辅助稳定剂结合时,可以观察到突出的协同作用。当加入季戊四醇(PER)时,PVC(包括CaSt2/ZnOr2)的初始颜色和长期稳定性显着增加,而二苯甲酰甲烷(DBM)只能提高其长期热稳定性。
    Zinc orotate (ZnOr₂), which is a new kind of poly(vinyl chloride) (PVC) stabilizer, is prepared in this work through the precipitation method, and its impact on the thermal stability of PVC is measured by thermogravimetric analysis (TG), Congo red test, and discoloration test. The results exhibit that the thermal stability of PVC is positively enhanced after the addition of ZnOr₂. In contrast with a commercial thermal stabilizer, zinc stearate (ZnSt₂), a noteworthy improvement was observed that ZnOr₂ could postpone the \"zinc burning\" of PVC. This is principally ascribed to the Or anion in the structure of ZnOr₂ being able to absorb the HCl released by PVC, and to supersede unstable chlorine atoms in the structure of PVC. In addition, blending ZnOr₂ with calcium stearate (CaSt₂) in diverse mass ratios can significantly accelerate the thermal stability of PVC. Optimum performance was achieved with a CaSt₂:ZnOr₂ ratio of 1.8:1.2. Moreover, an outstanding synergistic effect can be observed when CaSt₂/ZnOr₂ is coupled with other commercial auxiliary stabilizers. The initial color and long-term stability of PVC including CaSt₂/ZnOr₂ is significantly increased when pentaerythritol (PER) is added, while dibenzoylmethane (DBM) can only improve its long-term thermal stability.
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