聚氯乙烯制品中增塑剂迁移机理及抑制影响因素

聚氯乙烯(PVC)制品中含一定量的增塑剂成分,增塑剂在制品的加工和使用中,会产生不同程度的迁移和扩散问题。由于增塑剂与聚氯乙烯分子链段间的作用力是范德华力,因此从物化性质上讲,增塑剂的迁移和扩散成为必然。增塑剂的迁移和扩散可使PVC制品物化性能下降,同时可形成制品表面及接触物的污染,更为严重的是会给环境、人体健康带来一系列问题。因此,增塑剂迁移和扩散问题成为制约PVC制品广泛应用的障碍。本文讨论了聚氯乙烯中增塑剂迁移和扩散基本原理,重点介绍了影响增塑剂迁移和扩散的主要因素以及增塑剂迁移和扩散解析模型,归纳总结了多种能有效抑制PVC制品中增塑剂迁移和扩散问题的解决方法以及重大研究成果。     

聚酯增塑剂的合成与分析

聚酯增塑剂由二元酸和二元醇通过缩合反应制得．种类主要有己二酸类聚酯和苯酐聚酯等。聚酯增塑剂与一般常用的增塑剂最大的不同在于具有较大的分子量。聚酯增塑剂的分子量可以与PVC相当．因此与PVC具有更好的相容性。更由于其挥发性低，耐油及耐脂肪族或芳香族碳氢化合物的抽出，在油漆与橡胶中耐迁移，且耐老化性能优异．与低分子量增塑剂相比，聚酯增塑剂具有耐抽出、耐高温和迁移性小等方面性能超群的特点，使它享有“永久性增塑剂”之称，是发展较快的一类增塑剂。     

聚酯增塑剂的合成及性能测试

以己二酸、2-甲基丙二醇为原料,在混合固体酸催化下,以辛醇进行封端,通过控制反应物配比和反应温度合成了具有不同分子量的聚酯。将合成的聚酯增塑剂与邻苯二甲酸二丁酯复配使用对PVC制品进行实验,考察了增塑剂配比、聚酯分子量对PVC制品中DBP耐移动性和耐溶剂抽出性的影响。实验结果表明,在200℃、醇组分过量10%时合成的聚酯增塑剂的数均分子量达到4000以上。聚酯增塑剂与DBP复配应用于PVC塑料,能够降低PVC中DBP分子的迁移量和溶剂抽出量,从而大大提高了PVC材料使用范围。     

软质PVC中增塑剂迁移的抑制研究进展

增塑剂是软质聚氯乙烯(PVC)中最重要的一类助剂,然而由于增塑剂分子与PVC分子链间无化学键相连,在PVC制品加工和使用过程中,增塑剂分子不可避免地从PVC制品中发生迁移或扩散,不仅使PVC制品的物化性能下降,还给生态环境和人类健康带来一定的危害。因此由增塑剂迁移扩散所带来的问题引起人们的广泛关注,急需得到解决。当前,国内外很多研究者正通过对增塑剂进行共价键接枝改性的途径以及向PVC基质中添加外加剂等非共价键的途径抑制增塑剂的迁移。文章重点归纳了近年来国内外通过共价键及非共价键途径抑制增塑剂迁移扩散的最新研究成果,并展望了采用绿色经济合成路径、优化增塑配方等方式抑制增塑剂迁移的发展前景。     

环保醚酯型增塑剂TP-95在PVC中的应用

研究了环保醚酯型增塑剂TP-95和几种常用增塑剂对聚氯乙烯(PVC)的塑化效果、力学性能、耐寒性、耐热性及耐抽出性能的影响。结果表明:与添加的几种增塑剂相比,TP-95具有显著的增塑软化作用;随着增塑剂用量的增加,最低转矩明显下降,塑化时间缩短,塑化效果随之增强;与DOP和TOTM相比,TP-95表现出良好增塑效应及耐寒性;增塑剂用量均为50份时,TP-95的PVC开始热降解温度高于DOP和DOA;在水和环己烷介质中,随着随着增塑剂用量的增加,抽出损失随之增加;在环己烷介质中,TP-95的抽出损失为4.40%,低于TOTM和DOA,具有良好的耐抽出性。     

低分子量聚四氢呋喃二苯甲酸酯的增塑性能分析

以传统的邻苯二甲酸二辛酯（DOP）和聚醚型二甘醇二苯甲酸酯（DEDB）增塑剂作对比,对聚四氢呋喃二苯甲酸酯（PTMGDB₅₀₀）增塑剂增塑的聚氯乙烯（PVC）材料进行研究。本文对增塑剂增塑的PVC材料进行了FTIR和TG表征,并考察了其力学性能、耐乙醇抽出性及耐迁移性。结果表明,增塑剂PTMGDB₅₀₀增塑的PVC材料在力学性能上介于DOP和DEDB两者之间,而PTMGDB₅₀₀与PVC间的相互作用更强,在耐迁移、耐乙醇抽出、耐热及耐压等性能方面均优于DOP及DEDB,因此PTMGDB₅₀₀可作为部分替代DOP和DEDB的增塑剂。     

聚氯乙烯材料中增塑剂迁移率测试方法及影响因素研究

根据增塑剂的迁移特性,确定出一种增塑剂迁移率的测试方法。结果显示,测试方法的最适合测试条件为,时间2 h,温度60℃,增塑剂添加量60份,试片厚度1 mm。根据试验数据,有利于PVC制品生产厂对储存温度、时间、压力(制品叠加所产生)的选择,来最大程度降低制品中增塑剂的迁移风险。同时研究了加工温度、PVC树脂粉规格牌号、增塑剂种类、稳定剂添加量对增塑剂迁移的影响程度。并对各试验现象,从内部分子结构及形态,给出迁移机理的解释,为将来了解新助剂的迁移特性提供理论基础。     

增塑剂在PVC材料中损失问题的研究进展

简要说明了增塑剂的概念及种类,重点介绍了增塑剂在PVC材料中的耐久性问题,归纳总结了国内外减小或消除迁移和抽出的一些研究成果,并对研究成果进行了对比评价。     

盐用PVC苫盖薄膜中增塑剂在卤水环境中迁移规律研究

研究了盐用PVC苫盖薄膜中的增塑剂在卤水中的迁移情况及时间、盐度等因素对迁移的影响;以及增塑剂迁移对薄膜力学性能的影响。试验结果表明:采用极性较大的增塑剂制作的PVC薄膜不如采用极性较小的增塑剂制作的在卤水中耐迁移。     

PVC塑料制品中聚酯增塑剂的配方应用

聚酯增塑剂是极性高分子聚合物,与PVC有很好的相容性,加入PVC配方内,都能使PVC塑化时间有不同程度的提前,作为一种配方原料与助剂,常和DOP、环氧大豆油复配并用,由于聚酯增塑剂具有较强极性,与DOP在配方中亲和性还和其他的液体增塑剂产品的特性有关,当聚酯增塑剂用于PVC制品中能起到了吸引和固定其他增塑剂不向PVC制品的表面迁移的作用,     

Improving the migration resistance against phthalate plasticizer in polyvinyl chloride/graphene oxide composites

Phthalic plasticizer plays an important role in processing and manufacturing one of the universal polymer materials, poly (vinyl chloride) (PVC), which has been widely applied in every aspect of our lives. However, there still exists the intrinsic problem in migration resistance of phthalic plasticizer in long-term use. In this work, we take a facile and convenient approach by incorporating commercial graphene oxide (GO) into PVC matrix to prepare polyvinyl chloride/graphene oxide (PVC/GO) composites, forming a sheet structure for improving the migration resistance of phthalic plasticizer. The advantages of GO that has abundant oxygen-containing groups on its surface, including carboxyl groups at the sheet edges, epoxy groups, and hydroxyl groups on its basal planes. Especially, these oxygen-containing groups in GO are beneficial to blend with long molecular chain of PVC and the sheet structure of GO can prevent phthalic plasticizer migrating from interior PVC. Addition of GO not only effectively enhanced the mechanical properties of PVC/GO composites but also improve their migration resistance due to the sheet structure. This strategy provides an attractive way to solve the problem of migration of plasticizer with simple incorporation GO into the matrix of PVC, reinforcing the composite properties and broadening its applied fields.     

Plasticizer migration from cross‐linked flexible PVC: Effects on tribology and hardness

Uses of flexible poly(vinyl chloride) (PVC) are restricted by plasticizer migration affecting material properties. Moreover, the use of phthalate‐based plasticizers is being questioned worldwide because of their potential toxicity to humans and environment. Chemical modification of PVC structure is one of the most effective tools for reduction of plasticizer diffusion. In this work, a flexible dry blend based on cross‐linked PVC was obtained using a difunctional amine, namely isophoron diamine (IPDA) as the cross‐linking agent. The gel fraction was evaluated from insoluble portions obtained by means of solvent extraction; the efficiency of cross‐linking in reducing the plasticizer leaching was evaluated by migration tests. Effects of addition of IPDA on PVC thermal stability were determined by thermogravimetric analysis (TGA). The cross‐linking reaction turned out to be responsible for accelerating thermal degradation. Tribological properties of flexible uncross‐linked, cross‐linked and rigid PVC were determined. Flexible formulations were held in contact for 32 days with rigid PVC sheets. Plasticizer migration towards the interface caused an increase of dynamic friction compared to that of the reference rigid PVC.Vickers microhardness h_Vickers values of rigid PVC sheets decreased due to plasticizer surface absorption. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Energy and material cost savings with polyester/monomeric plasticized PVC compounds

Many plasticized PVC articles are exposed to harsh environments that cause loss of plasticizer through extraction, volatility, or migration. In order to survive in these applications, the PVC must contain plasticizers that have a reasonable degree of permanence. Two approaches are the use of low molecular weight polyester plasticizers, or higher molecular weight polyester/monomeric plasticizer blends. The blend approach can give better cost-performance and, due to faster fusion, reduced energy/manufacturing costs. The blends maintain their advantages even upon further dilution with monomeric plasticizers and in permanence tests of long duration. Although better than monomeric plasticizers, neither the low molecular weight polyester nor the blend system is recommended for applications requiring the ultimate in migration resistance.     

Surface treatment of plasticized poly(vinyl chloride) to prevent plasticizer migration

In this investigation, plasticized poly(vinyl chloride) (PVC) was treated with poly(azido acrylate)s to prevent plasticizer migration. This was achieved by modification of PVC sheets with poly(azido acrylate)s in a dichloromethane solution followed by irradiation under UV light. The surface‐modified PVC sheets with poly (azido acrylate)s were characterized with Fourier transform infrared spectroscopy and scanning electron microscopy analyses. The migration of the plasticizer was prevented to a large extent from modified PVC in comparison with unmodified PVC. The amount of plasticizer migration with respect to the irradiation time, incubation time, and number of dipping times was evaluated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

PVC增塑剂偏苯三酸基聚酯的研究

采用“二步法”将偏苯三酸酐（TMA）和甘油（Gl）经酯化、缩聚反应得到环保、可生物降解的偏苯三酸聚酯（P-Gl-TMAI）。将合成的P-GI-TMAI与邻苯二甲酸（2-乙基己基）酯（DOP）分别添加到聚氯乙烯（PVC）树脂中进行塑炼实验,研究2种增塑剂与PVC树脂的相容性能、塑炼试片的力学性能以及耐迁移性能。结果表明,与DOP相比,P-Gl-TMAI与PVC的相容性较好;且前者塑炼试片的拉伸强度达18.99 MPa,断裂伸长率为454.89 %;在挥发性和抽出性试验中,P-Gl-TMAI制备的试片分别仅有3.02 %和15.31 %的质量损失率,其韧性与耐迁移性均高于DOP。     

Synthesis and application of an environmental epoxy plasticizer with phthalate-like structure based on tung oil and cardanol for poly(vinyl chloride)

An epoxidized cardanol tungoleate (ECT) based on tung oil and cardanol was synthesized through esterification and epoxidation. The chemical structure of the compound was verified by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H-NMR). The plasticizing effects of ECT as the main plasticizer in poly(vinyl chloride) (PVC) was studied and compared with the commercial plasticizer dioctyl phthalate (DOP). The thermal migration stabilities, the thermal degradation process and the mechanical properties of PVC samples and the plasticization mechanism of ECT for PVC were investigated through the use of volatility, extraction, discoloration, and tensile tests as well as thermal gravity analysis (TGA), TGA–FTIR analysis, electronic universal testing machine and dynamic mechanical analysis (DMA). Compared with DOP, the ECT plasticized PVC can exhibits better thermal stability, more excellent tensile strength (17.28 MPa) and higher stretchability (629.41%), which is 1161% higher than DOP (1.37 MPa) plasticized PVC film. In addition, the migration resistance and volatility stability of ECT are much better than DOP. Therefore, this fully bio-based plasticizer based on tung oil and cardanol is a promising alternative plasticizer for PVC and may be an excellent phthalate substitute from the perspective of human health and sustainable development.     

不同度数白酒介质中PVC制品增塑剂迁移行为研究

采用高效液相色谱仪测定聚氯乙烯（PVC）制品中传统增塑剂邻苯二甲酸二辛脂（DOP）、对苯二甲酸二辛脂（DOTP）和环保增塑剂柠檬酸三丁酯（TBC）、乙酰柠檬酸三丁酯（ATBC）,在42 °、46 °、55 °白酒中的迁移规律,并用Gaussian 03程序对其结构进行模拟计算,探讨了分子结构影响增塑剂迁移行为的机理。结果表明,随着与介质接触时间的延长、白酒度数的增大,增塑剂的迁移率逐渐增大;不同种类分子结构的增塑剂的迁移能力有较大的差异性,增塑剂分子的偶极矩越大,其分子极性越强,增塑剂与PVC相容性就越好,其迁移率越小;几种增塑剂中,迁移率大小为：TBC＞ATBC＞DOP＞DOTP。     

Effect of liquid plasticizers on crystallization of PCL in soft PVC/PCL/plasticizer blends

In this work, poly(ε-caprolactone) (PCL) and liquid plasticizer were combined used to plasticize poly(vinyl chloride) (PVC), and the possibility of using PVC/PCL/plasticizer blends to fabricate soft PVC with enhanced migration resistance was investigated. Through partial replacement of liquid plasticizers in soft PVC by equal quantity of PCL, flexibility was maintained while extraction loss of plasticizer by organic solvent was reduced significantly. Furthermore, crystallization of PCL in PVC/PCL/plasticizer blends with low PCL content was observed, and crystallization rate of PCL was found to be influenced by plasticizer contents and structures. For instance, crystallization rate of PCL in PVC/PCL/diisononyl phthalate (DINP) (100/40/100) was 3.7 times faster than in PVC/PCL/DINP (100/40/80), while crystallization rate of PCL in PVC/PCL/dioctyl adipate(DOA)(100/40/100) was 8.3 times faster than in PVC/PCL/diisononyl cyclohexane-1,2-dicarboxylate (DINCH) (100/40/100). Low-field ¹H NMR test manifested that different crystallization rate of PCL in PVC/PCL/plasticizer blends with different plasticizer structures was triggered by difference in plasticizers' compatibility with PVC, that is, the number of interaction point between PVC and plasticizers. It is concluded that PCL crystallization favored by liquid plasticizers in PVC/PCL/plasticizer blends was induced by interaction competition between PVC/plasticizer and PVC/PCL. As plasticizer content increases or its compatibility with PVC decreases, interaction competition becomes more intense and consequently faster crystallization of PCL occurs. Thus, to obtain soft PVC products with improve migration resistance while avoiding PCL crystallization, the total content of plasticizer (including both liquid plasticizer and PCL) should be lower than 66 phr (40 wt %). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48803.     

聚氯乙烯胶带增塑剂迁移的研究

用全反射红外技术对聚氯乙烯薄膜及其胶带进行了增塑剂迁移性能的研究。增塑剂的迁移经一定时间后达到平衡。对聚氯乙烯薄膜来说,增塑剂迁移的扩散系数约为1×10~(-7)mm~2/min.而对不同配方的聚氯乙烯胶带,影响增塑剂迁移性能的因素是催化剂的类型及用量,及胶粘剂的类型。     

An innovative plasticizer for flexible PVC food contact applications

When flexible polyvinyl chloride (PVC) is used in food contact applications, there is potential for plasticizer migration. Concern over this migration has led to the development of a novel plasticizer. Eastman EPZ plasticizer is a distilled acetylated monoglyceride (DACM). EPZ is a fraction from the molecular distillation of the reaction mixture prepared by the interesterfication of fully hydrogenated coconut oil and glyceryl triacetate. It is lawful for both direct and indirect food contact according to U.S. Food & Drug Administration regulation 29 CFR 172.828. The performance of EPZ plasticizer compared with adipate and citrate plasticizers confirms its usefulness in flexible PVC. This performance, combined with its clearance as a direct and indirect food additive, offers vinyl formulators a new tool to expand the flexible vinyl market.