Properties of a PVAc emulsion adhesive using a nonphthalate plasticizer obtained by condensation of 2-methylpropanal

The requirement to search for new plasticizers and coalescents for making water-based dispersion adhesives from poly(vinyl acetate) is of particular importance, especially now, after banning all kinds of toxic phthalates and restricting the use of glycol derivatives classified as volatile organic compounds. The poly(vinyl acetate) adhesive was synthesized using the eco-safe plasticizer – 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate. The plasticizer was obtained by aldol condensation of 2-methylpropanal, byproduct of oxy synthesis from propylene. Its desirable properties were confirmed by comparing the composition of the adhesive comprising poly(vinyl acetate) as the principal component and the plasticizer as the additive. 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate and commonly known plasticizers, such as: diisobutyl phthalate and diethylene glycol n-butyl ether acetate were used as the plasticizers in the experiment. The adhesives were compared in respect of the following parameters: dry weight, pH, viscosity, minimum film forming temperature, penetrability, setting time and stability in time. The test results indicate that 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate can be used successfully as a plasticizer for making wood adhesives in the range from 2.0 to 2.5% of the adhesive formulation and for making bookbinding adhesives in the range from 4.7 to 5.6% of the adhesive formulation. This enables an about twofold reduction of the amount of the plasticizer, in comparison with the adhesive based on diisobutyl phthalate. 3-hydroxy-2,2,4,-tri-methyl pentyl isobutyrate can be used in dispersion adhesive formulations, thus replacing the undesirable, toxic phthalate esters and polyglycol derivatives classified as volatile organic compounds.     

Plasticizer structure/performance relationships

Plasticizers for poly(vinyl chloride) may be organized into eight chemical families and by seven key performance criteria. Cost-effective general-purpose phthalates provide a base line for comparing all other plasticizers. The wide range of performance characteristics associated with various phthalate isomers substantiates the large proportion of phthalate esters that are utilized as plasticizers. This article summarizes plasticizer structural/performance relationships using quantitative comparisons of cost, plasticizing efficiency, plastisol solvation characteristics, dryblending, volatility, and low temperature performance properties in PVC. Some generalizations are also made concerning structural effects of the alcohol isomers used in the syntheses of the various types of plasticizer esters.     

Renewable (waste) material based polyesters as plasticizers for adhesives

The aim of the presented work was to replace phthalate based plasticizers with environmentally friendly materials to provide similar properties for poly(vinyl acetate) (PVAc) adhesives.Polyesters synthesized from the liquefied wood (PE-LW) and depolymerized polyethylene terephthalate (PE-PET) were used as renewable raw materials and evaluated as plasticizers used in PVAc dispersion adhesives for flooring applications. As a reference plasticizer, 1,2,3-triacetoxypropane was used.PVAc adhesives were evaluated with respect to solids content, viscosity, glass transition temperature (T_g), tensile shear strength and binding strength.TGA analysis showed significant differences between the thermal stability of added polyesters and the commercial plasticizer. Samples prepared with PE-PET exhibit the best thermal stability even with an increase of 25% PE-PET. The addition of coalescing agents or plasticizers leads to a temporary softening of the PVAc polymer and a decrease in the glass transition temperature.The type and content of plasticizer have great influence on wood–wood binding strength, tensile strength and elongation.The requirements for the mechanical properties of adhesives were fulfilled by the compositions containing 8.8% (w/w) of PE-PET and 20% (w/w) of PE-LW.     

增塑剂对氯化聚乙烯防水卷材增塑效果的研究

分析了几种增塑剂[邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二辛酯(DOP)、邻苯二甲酸二异癸酯(DIDP)、癸二酸二辛酯(DOS)、偏苯三甲酸三辛酯(TOTM)以及氯化石蜡等]对氯化聚乙烯(CPE)防水卷材的增塑机理。在保持其他条件不变的前提下,选取增塑剂的份数为25份,并在此基础上从力学性能、耐温性能、流变性能以及微观结构四个方面比较各种增塑剂与CPE树脂的相容性,从而比较它们的增塑效果。结果表明:DSC以及电镜结果显示邻苯类增塑剂效果明显优于其他类型增塑剂;其中DOP为主增塑剂的体系综合性能最好;DOS作为主增塑剂时具有良好的耐低温析出性;DIDP作为主增塑剂时具有耐高温析出性;氯化石蜡可作为辅助增塑剂;以上增塑剂可根据各自特点复配使用。     

环氧大豆油改性透明环氧树脂胶粘剂的研究

以环氧大豆油(ESO)为环氧树脂(EP)的增塑剂、环氧氯丙烷(ECH)和丙烯腈(AN)改性己二胺为固化剂,制得ESO改性EP胶粘剂。探讨了增塑剂种类和含量对EP胶粘剂性能的影响。结果表明:当n(己二胺):n(ECH):n(AN)=1:0.3:1.5、w(ESO)=20%时,相应EP胶粘剂的剪切强度、断裂伸长率和外推起始温度分别比纯EP体系增加了10%、400%和20%;ESO是一种高增韧性、高耐热性的环保型增塑剂,相应EP胶粘剂的透明性、柔韧性和耐高(低)温性俱佳。     

增塑剂的选择与邻苯二甲酸酯的替代品

在拟定一款软质聚氯乙烯（PVC）配方时,所开发的产品能否满足客户的性能指标和成本要求,在很大程度上取决于适当的增塑剂体系的选择。在所有原料组分中,增塑剂会对产品的最终性能造成最大的影响。本研究将论述在选择增塑剂时所涉及的程序,先从通用型增塑剂开始,然后考虑邻苯二甲酸酯的替代品及其他增塑剂。     

The effects of plasticizers on the properties of poly(vinyl chloride) foams

The effects of plasticizers on poly(vinyl chloride) (PVC) plastisol mixtures were investigated. The investigations were carried out by determining the density of the PVC foam obtained by gelling the plastisol, as well as its elasticity and degree of expansion. Two series of experiments using different types of PVC were performed, using eight plasticizers, individually or as mixtures. Two-component plasticizer mixtures showed better properties than single-component plasticizers, and mixtures of di-iso-heptyl phthalate (DiHP) and butyl benzyl phthalate (BBP) proved to be the most appropriate. The effect of plasticizer amount also was investigated, and of the three parameters studied, the foam density, which steadily increased with plasticizer amount, was the critical one. It was also shown that in order to obtain consistent results, the foam expansion had to be precisely timed and the temperature carefully chosen.     

国内外邻苯二甲酸酯类增塑剂的现状和展望

对邻苯二甲酸酯类增塑剂的国内外现状作了评述,并对我国提高DOP和高分子量邻苯二甲酸酯类增塑剂的比例、降低DBP的比例、开发高性能的复合增塑剂提出了积极的建议。     

Soft PVC foams: Study of the gelation,fusion, and foaming processes. II. Adipate,citrate and other types of plasticizers

Plasticized poly(vinyl chloride) (PVC) is one of the most useful polymeric materials on an industrial scale because of its processability, wide range of obtainable properties, and low cost. PVC plastisols are used in the production of flexible PVC foams. Phthalates are the most used plasticizers for PVC, and in a previous article (part I of this series), we discussed the influence of phthalate ester type plasticizers on the foaming process and on the quality of the foams obtained from the corresponding plastisols. Because the use of phthalate plasticizers has been questioned because of possible health implications, the objective of this work was to undertake a similar study with 11 commercial alternative plasticizers to phthalates. The evolution of the dynamic and extensional viscosity and the interactions and thermal transitions undergone by the plastisols during the heating process were studied. Foams were obtained by rotational molding and were characterized by the determination of their thermomechanical properties, density, and cell size distribution. Correlations were obtained between the molecular weight and structure of the plasticizer and the behavior of the corresponding plastisols. After the characterization of the final foamed product, we concluded that foams of relatively good quality could be prepared with alternative plasticizers for replacing phthalates. Several plasticizers {Mesamoll (alkylsulfonic phenyl ester), Eastman 168 [bis(2‐ethylhexyl)‐1,4‐benzenedicarboxylate], Hexamoll [di(isononyl) cyclohexane‐1,2‐dicarboxylate], Citroflex A4 acetyl tributyl citrate (ATBC), and Plastomoll (dihexyl adipate)} were found to be interesting alternatives in the production of soft PVC foams because they provided very good quality foams with properties similar to, or even better than, those obtained with phthalate plasticizers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

水溶性粘合剂的配制及其性能研究

先通过聚乙酸乙烯酯(PVAc)的醇解制备出聚乙烯醇(PVA),再用聚乙烯醇在酸性条件下与甲醛缩合,得到聚乙烯醇缩甲醛(PVF),再以聚乙烯醇和聚乙烯醇缩甲醛为基料,以邻苯二甲酸二丁酯(DBP)为增塑剂,聚乙二醇-400(PEG-400)为增韧剂,水为溶剂,以鱼油为分散剂,配制了不同工艺配方的水基粘合剂,考察了增塑剂、增韧剂的加入量对粘合剂的透明度、稳定性、溶解度、粘弹性等的影响。实验结果表明,当质量比PVA∶PVA∶水=9.6∶9.6∶80.8,鱼油、聚乙二醇-400、DBP的添加量分别为4%、1.6%、2.0%时,所配制的粘合剂有相对较好的综合性能。     

HEMA接枝改性天然胶乳的制备及其粘接性能研究

以甲基丙烯酸羟乙酯(HEMA)作为天然胶乳(NRL)的接枝改性剂,采用乳液聚合法制备了NR-g-HEMA[HEMA接枝NR(天然橡胶)]胶乳;然后以此为基体,并以水溶性松香树脂为增黏树脂、邻苯二甲酸二丁酯(DBP)为增塑剂等,制备相应的NR-g-HEMA胶粘剂;最后,用该胶粘剂压制胶合板,并对胶合板的粘接性能进行了测定。结果表明:采用单因素试验法优选出制备NR-g-HEMA胶乳的最佳工艺条件为m(干态单体)∶m(NRL)∶m(引发剂)∶m(活化剂)∶m(交联剂)=20∶100∶0.2∶0.2∶0.1、反应时间为8 h和反应温度为16℃,此时相应胶合板的剪切强度(1.88 MPa)符合Ⅲ类胶合板的指标要求。     

Study on volume ratio and plasticizer screening of free coating membranes composed of ethyl cellulose and chitosan

The aim of this study was to optimize the formula of free blended coating membrane of ethyl cellulose (EC) and chitosan (CS), including their suitable ratio range and the best plasticizer used. The dry films were produced by a casting/solvent evaporation method, with different volume ratio of EC and CS solution plasticized by various plasticizers, respectively. The wet films were prepared by immersing dry films in pH 6.8 phosphate buffer saline (PBS) for 24 h. The promising ratio range of EC/CS was below 20/5 or 20/6 with various plasticizer, which was determined by comparing the viscosity of the blended solutions and the morphology of the blended films. The efficiency of plasticization was evaluated by measuring glass transition temperature (T_g). All the testing plasticizers have good compatibility with EC or CS and dibutyl phthalate (DBP) have the strongest efficiency inducing the lowest T_g (39.9°C) of the film. Mechanical properties were evaluated by the ratio of tensile strength (T) to elastic modulus (E). In the wet state, the films with DBP had the highest T/E value (1.2). The results of leaching of plasticizers also verified that DBP was the most stable plasticizer in the films. The release rates of tetramethylpyrazine phosphate (TMPP) through the pellets coated with the blended films of EC/CS (20 : 6 v/v) plasticized by various plasticizers showed that the more water‐soluble the plasticizer was, the more quickly TMPP dissolved from the coated pellets, which further indicated that the water‐insoluble plasticizers (such as DBP) could be more applicable to keep the sustained or controlled release property of the blended films in wet state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1932–1939, 2006     

Emissivity values for poly(vinyl chloride) with varying plasticizer compositions

The emissivity of plasticized poly(vinly chloride) (PVC) containing varying compositions and amounts of plasticizer was investigated. The four plasticizers examined were dibutyl phthalate (DBP), dioctyl phthalate (DOP), diisodecyl phthalate (DIDP) (Phthalic acid type), and dioctyl adipate (DOA) (adipic acid type). The emmissivity of plasticized PVC film increased almost equally with the difference in the compositions between DOP and DOA. It was also clear that the emissivity of the plasticized PVC film decreased gradually with the molecular sequence length of DBP, DOP, and DIDP.     

Effect of plasticizer functionality on the performance properties of flexible PVC compounds

This paper is on the enhancement of physical properties achieved through utilization of linear plasticizers in flexible PVC compounds. This paper also emphasizes the use of statistical methods and designs of experiments. In a series of experimental designs, electrical, oven-aging, and low temperature performance of commercially available phthalate plasticizers were evaluated. Test data will be given to show the effect of plasticizer functionality on the performance properties of flexible PVC compounds.     

Performance Evaluation and Biodegradation Study of Polyvinyl Chloride Films with Castor Oil-based Plasticizer

In the present study, a renewable resource-based plasticizer was synthesized by the lipase-catalyzed esterification reaction of furfuryl alcohol (FA) and castor oil fatty acid (COFA). The resultant ester (FA-COFA ester) was used as secondary plasticizers to the polyvinyl chloride (PVC) films. The PVC films were formulated using the combination of a conventional plasticizer di-butyl phthalate (DBP) and FA-COFA ester as a secondary plasticizer at different concentrations. Films were characterized by X-ray diffraction analysis, scanning electron microscopy, thermal analysis, mechanical performance, and migration stability. A biodegradability study of the PVC films showed increased degradability with increasing concentration of the FA-COFA ester in the PVC film. The study showed that ester of FA and COFA could be a substitute of DBP by as much as 80% of the total plasticizer with improved elongation and tensile properties, and such a kind of sustainable resource-based PVC blend films could be used as a good packaging material with biodegradable property.     

The role of plasticizer in optimizing the rheological behavior of ceramic pastes intended for stereolithography-based additive manufacturing

Adding plasticizer is an efficient way to regulate the rheological behavior of ceramic paste and quality of green body in stereolithography-based additive manufacturing. The type and content of plasticizers (polyethylene glycol (PEG) and dibutyl phthalate (DBP)) had substantial effects on the rheological behavior and solid loading of ceramic paste, leading to varied macro / micro structure and strength of the green and sintered parts. DBP significantly reduced the viscosity and increased solid loading, and could adjust the flexibility of the green body by reducing the crosslinking density of UV curing system. PEG could inhibit crack initiation to some extent, but it was less effective for preventing cracking than DBP on ceramic parts with large-sized cross sections. It was concluded that DBP was more suitable as a plasticizer in alumina paste for SL additive manufacturing to form dense parts without defects.     

Formulation and mechanical characterization of PVC plastisols based on low‐toxicity additives

New formulations of plastisols based on low‐toxicity plasticizers were proposed and characterized. Traditional phthalate plasticizers were replaced in the plastisols studied in this research by polymeric plasticizers (i.e., saturated polyesters), produced by the reaction of a diol and a carboxylic acid. The main drawback for the use of these plasticizers in formulations of PVC plastisols is a significant increase of the paste viscosity, which decreases their processability; thus, the use of additional additives to reduce viscosity is recommended. This study also includes the optimization of the processing conditions (cure temperature and time) of the proposed plastisols: complete cure was obtained at 140°C and 10 min. It is reported that the final properties of plastisols are very sensitive with respect to the processing conditions; in fact, insufficient plasticization or degradation can affect the material when processed out of the optimum conditions. The influence of the plasticizer concentration on mechanical and optical properties, such as tensile strength, hardness, brightness, and the like, is also reported. In summary, the proposed plastisols, with low‐toxicity plasticizers, offer a valid alternative to traditional PVC plastisols based on phthalate plasticizers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1881–1890, 2001     

可剥离型丙烯酸酯类压敏胶乳液的研制

以丙烯酸酯类为主要原料，以烯丙基烷基磺基琥珀酸双酯钠盐M10-S为反应型乳化剂，采用乳液聚合方法制备了一种可剥离型压敏胶乳液。探讨了N-羟甲基丙烯酰胺（NAM）、M10-S、增塑剂及基材对压敏胶性能的影响。结果表明，当NAM用量为总单体质量2．0％，M10-S为单体总质量0．6％，用总乳液质量20％的邻苯二甲酸二辛酯（DoP）为增塑剂，PP或不锈钢为基材时压敏胶具有较好的可剥离性及综合性能。     

Preparation and evaluation of acetylated mixture of citrate ester plasticizers for poly(vinyl chloride)

Tributyl citrate (TBC) and acetyl tributyl citrate (ATBC), as phthalate alternative plasticizers, show limited application due to low migration resistance, high volatilization rate and intense respiratory irritation. Meanwhile, the developed pure citrates, such as butyryl trihexyl citrate (BTHC) due to its high cost, and triisooctyl citrate (TOC) and acetyl triisooctyl citrate (ATOC) due to their low absorption property, are not attractive plasticizers to manufacture phthalate-free poly(vinyl chloride)s (PVCs). In this study, we developed an effective method to synthesize acetylated mixture of citrate esters (ATMC) composed of acetyl (dibutyl-monoisooctyl) citrate, acetyl (monobutyl-diisooctyl) citrate, and a small amount of ATBC and ATOC, as an alternative for phthalate plasticizers. ATMC combines the advantages of ATBC in being easily absorbed and ATOC in having good migration resistance. Characterization results showed that the dynamic viscosity, absorption property and plasticizing efficiency of ATMC11 (1:1 molar ratio of n-butyl alcohol to 2-ethylhexanol) were similar to those of di(2-ethylhexyl) phthalate (DEHP). The thermal volatilization and migration of ATMC11 were less than those of ATBC, and were comparable to those of DEHP, which could be attributed to the improved compatibility with PVC. The performance of ATMC11 was improved compared with that of the mixture of ATBC and ATOC. As an environmental bio-based plasticizer, ATMC11 was demonstrated as a biologically safe plasticizer by biological safety evaluation tests. Therefore, ATMC11 with excellent comprehensive performances and low cost can be candidate as an ideal phthalate alternative for soft PVC formulations.     

乳液型改性PS胶粘剂的制备与性能研究

本文提出厂乳液型改性PS胶粘剂的制备工艺，研究了改性剂——酚醛树脂和增塑剂DBP用量对其粘接性能的影响，确定了改性剂和DBP的最佳用量分别为PS的1．5％～2．5％和8％～10％。