环保增塑剂环己烷1,2二甲酸二异辛酯的合成与应用

以环己烷1,2二甲酸酐(HHPA)与异辛醇为原料,甲烷磺酸为催化剂,合成了环保增塑剂环己烷1,2二甲酸二异辛酯（DEHCH）,并与邻苯二甲酸二异辛酯（DEHP）的增塑性能进行了对比。经单因素实验得到最佳的合成工艺条件为：醇酐摩尔比为2.6∶1.0,催化剂用量为酸酐质量的0.25 %,反应温度为170 ℃,反应时间2 h,酯化率可达到97.89 %。并用红外光谱、核磁共振、质谱表征了产物的分子结构,通过力学性能的对比可知,合成的DEHCH与DEHP有着相似的增塑性能,可以作为一种替代邻苯二甲酸酯类的增塑剂。     

环保增塑剂环己烷1,2-二甲酸二异辛酯的合成

以环己烷1,2-二甲酸酐(HHPA)和异辛醇为原料,活性炭负载甲烷磺酸为催化剂,合成环己烷1,2-二甲酸二异辛酯。经单因素实验得到最佳工艺条件为:n(异辛醇)∶n(环己烷1,2-二甲酸酐)=2.4∶1.0,催化剂用量为醇酐总质量的2.1%,带水剂环己烷用量6 mL,反应温度160～180℃,反应时间2.5 h,酯化率可达99.82%。催化剂重复使用4次后酯化率仍大于90%。产品为浅黄色油状液体,经HPLC测定酯色谱纯度为99.15%。测定了其酸值、密度、加热减量、黏度、热重曲线等,结果表明,环己烷1,2-二甲酸二异辛酯符合增塑剂的性能要求。     

Novel branched poly(ɛ‐caprolactone) as a nonmigrating plasticizer in flexible PVC: Synthesis and characterization

A series of hyperbranched poly(?‐caprolactone) (HPCLs, denoted as D_X) with different molecular weights were synthesized by the copolymerization of GPCL (PCL initiated by glycidol) and succinic anhydride. The chemical structure of D_X was characterized by ¹H‐NMR gel permeation chromatography and inherent viscosity, and D_X was used as the plasticizer for poly(vinyl chloride) (PVC) compared to traditional plasticizer di‐(ethylhexyl) phthalate (DEHP). The thermal properties, morphology, mechanical properties, and migration stabilities of PVC films were explored with differential scanning calorimetry, thermogravimetric analysis, scanning electron microscope, tensile, and migration tests. PVC/D₁ exhibited the best plasticization efficiency up to 107%, with enhanced tensile strength (18.5 MPa) and ultimate elongation (416%) compared to PVC/DEHP (11.5 MPa and 375%, respectively). PVC/D₁ exhibited remarkably high plasticization efficiency as compared to PVC/DEHP at a plasticizer concentration of PVC below 40 wt %. Moreover, the migration test for PVC/D_X films exhibited minimal plasticizers migration even at very harsh conditions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46542.     

Rosin‐derived poly(vinyl chloride) plasticizer: Synthesis,structure, and properties

In this work, rosin‐based plasticizer was synthesized by Diels–Alder (DA) and esterification. First, the maleopimaric acid (RT) was obtained by DA between the double bond of rosin and maleic anhydride. Then, the carboxyl group and anhydride group of RT was esterified with tetrahydro geraniol to obtain the rosin‐based polyacid esters (RTT) under the catalysis of p‐toluene sulfonic acid. The structure of RT and RTT was detected by FTIR and ¹H‐NMR. RTT was used as main plasticizer to obtain plasticized polyvinyl chloride (PVC) materials and compared with DOP. The results showed that RTT improved the thermal stability and reduced T_g of PVC film. Plasticized PVC films had excellent mechanical properties with the elastic modulus of ?4,793.67 MPa and tensile strength of ?111.86 MPa, higher than that of pure PVC and DOP‐6. RTT showed better volatility stability, migration, and solvent extraction in PVC compared to DOP. J. VINYL ADDIT. TECHNOL., 26:180–186, 2020. © 2019 Society of Plastics Engineers     

Ester‐amide based on ricinoleic acid as a novel primary plasticizer for poly(vinyl chloride)

Utilization of ricinoleic acid as a raw material for the synthesis of green plasticizer would offer an alternative to the phthalate plasticizers. Ester‐amide of ricinoleic acid was synthesized by a two‐step reaction with dibutyl amine and benzoic acid; and then utilized as primary plasticizer in PVC. Ester‐amide plasticizer was added up to 40 phr in PVC; and the prepared PVC sheets were characterized for mechanical, X‐ray diffraction, thermal, rheological, colorimetric, and exudation properties. Addition of the ester‐amide plasticizer demonstrated good incorporation and plasticizing performance in PVC. Viscosity of PVC decreased with increased addition of ester‐amide plasticizer. The dark color of the synthesized plasticizer could have constraints on its application areas; however, the prepared samples illustrated negligible weight loss in the exudation test, attributed to better compatibility between them brought about by the ester, tertiary amide and polarizable benzene ring in the ester‐amide plasticizer with the C‐Cl polar linkage in PVC. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41913.     

Evaluating effects of biobased 2,5‐furandicarboxylate esters as plasticizers on the thermal and mechanical properties of poly (vinyl chloride)

We synthesized 2,5‐furandicarboxylate esters [i.e., dibutylfuran‐2,5‐dicarboxylate, diisoamylfuran‐2,5‐dicarboxylate, and di(2‐ethylhexyl)furan‐2,5‐dicarboxylate] and investigated their potential application as plasticizers of commercial poly(vinyl chloride) (PVC) products. Fourier transform infrared analysis, mechanical tests, scanning electron microscopy investigation, differential scanning calorimetry analysis, dynamic mechanical thermal analysis, thermogravimetric analysis (TGA), melt flow rate (MFR) measurement, and plasticizer migration measurements were used to the evaluate the comprehensive properties of the blended products. The results of the tensile tests demonstrate that the blends exhibited antiplasticization and flexible plastic characteristics at 10 and 50 phr in PVC, respectively. Moreover, flexural and impact test data indicate that the three types of blends exhibited a similar tendency: the hardness decreased continuously as the amount of plasticizer increased. Their morphology indicated that all of the plasticizers had good compatibility with PVC. The resulting glass‐transition temperature of the investigated plasticizers was lower than that of pure PVC, and reduction was largest for the plasticizer with the highest molecular weight. TGA revealed that the thermal degradation of blended polymers occurred in three stages and that all of the blends were stable up to 180°C. Finally, the MFRs of all of the specimens indicated that the addition of a higher concentration of lower molecular weight biobased esters resulted in improved fluidity, but these compounds migrated more easily from the blends. Hence, 2,5‐furandicarboxylic acid derived from biomass has potential as a plasticizer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40938.     

Epoxidation of modified natural plasticizer obtained from rice fatty acids and application on polyvinylchloride films

In recent years, much research effort has been driven to develop alternative plasticizers for medical and commodity plastic materials. In this study, a modified natural plasticizer, synthesized by esterification of rice fatty acids, was modified by epoxidation with peroxy acid generated in situ. Two natural epoxidized plasticizers were obtained, using peracetic acid (NP‐Ac) and peroctanoic acid (NP‐Oc) as reagent. PVC films after addition of these natural epoxidized plasticizers presented fairly good incorporation and plasticizing performance, as demonstrated by results of mechanical properties, T_g values (as shown by DSC), optical microscopy, exudation, and migration tests, FTIR and X‐ray diffraction obtained for plasticized PVC films. NP‐Ac plasticizer presented enhanced plasticizing performance compared with NP‐Oc, probably due to a higher epoxidation degree obtained in the reaction with peracetic acid. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of a novel aliphatic polyester based on itaconic acid

A novel potentially biobased aliphatic polyester poly (butylene 2‐methylsuccinate) (PBMS) was synthesized from 1,4‐butanediol (BDO) and 2‐methylsuccinate acid (MSA) via direct esterification and polycondensation route using tetrabutyl titanate (TBT) as catalyst. The reaction conditions were investigated in detail. The proper molar ratio (1.08:1) of BDO to MSA was determined through balancing the reaction efficiency and costs of reactants. TBT was found to be an effective catalyst, and its content (0.1 mol% of MSA) was optimized based on the esterification ratio and intrinsic viscosity. The molecular weight of PBMS polymers was governed by the polycondensation time. The weight average molecular (M_w) characterized by gel permeation chromatography (GPC) ranged from 5,800 to 8,700 g/mol. The polyester was also characterized by nuclear magnetic resonance spectroscopy (¹H NMR), differential scanning calorimeter and thermogravimetric analysis. The results showed that the glass transition temperature continuously increased with molecular weight. The polyester had excellent thermal stability, and its decomposition temperature increased with the molecular weight. As new potentially biobased polyester plasticizer, desirable mechanical properties were achieved at the weight ratio of PBMS was 80/100 and 50/100. In addition, the PBMS/poly(vinyl chloride) (PVC) blends had superior migration‐resistant property to the low‐molecular weight plasticizer dioctyl phthalate for PVC. POLYM. ENG. SCI., 54:2515–2521, 2014. © 2013 Society of Plastics Engineers     

Highly Enantioselective Michael Addition of Cyclic 1,3‐Dicarbonyl Compounds to β,γ‐Unsaturated α‐Keto Esters

A highly enantioselective Michael addition of cyclic 1,3‐dicarbonyl compounds to β,γ‐unsaturated α‐keto esters catalyzed by amino acid‐derived thiourea‐tertiary‐amine catalysts is presented. Using 5 mol% of a novel tyrosine‐derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short reaction time.     

Characterization of 1,5‐pentanediol dibenzoate as a potential “green” plasticizer for poly(vinyl chloride)

1,5‐Pentanediol dibenzoate (PDDB) was evaluated as a potential “green” plasticizer for poly(vinyl chloride) (PVC) at concentrations ranging between 20 and 80 parts by weight per hundred parts of resin. The results of glass transition temperature (T_g) and tensile tests of PDDB blends with PVC were compared with those for blends of the commercial plasticizers di(2‐ethylhexyl) phthalate (DEHP), di(ethylene glycol) dibenzoate (DEGDB), and di(propylene glycol) dibenzoate (DPGDB) in PVC. The depression in T_g and the tensile properties were comparable for a PDDB/PVC blend at a fixed composition to those of blends with DEHP, DEGDB, and DPGDB. The PDDB was subjected to biodegradation using co‐metabolism by the common soil bacterium Rhodococcus rhodochrous (ATCC 13808). After 16 days of growth, nearly all of the PDDB was degraded, and only small amounts of transient, unidentified metabolites were observed in the growth medium during the experiment. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers     

均相催化六氢苯酐与C10直链醇制备环保增塑剂及其性能

采用均相催化剂钛酸四丁酯,以六氢苯酐和C10直链醇癸醇为原料,进行酯化得到高纯度的环保增塑剂环己烷1,2二甲酸二癸酯(DIDCH)。考察了醇酸摩尔比、催化剂种类及用量、反应时间、反应温度对酯化率的影响,确定了最佳工艺条件为：醇酸摩尔比为2.8∶1,反应时间为3 h,反应温度为200 ℃,催化剂用量为六氢苯酐质量的1.5 %。产品为无色透明油状液体,酯化率可达到99.48 %。采用傅里叶变换红外光谱(FTIR)及气相质谱联用仪(GC-MS)对DIDCH结构及纯度进行表征,将DIDCH作为增塑剂应用在聚氯乙烯( PVC)中。结果表明,使用DIDCH增塑的PVC试样,热老化试验试样变黄时间为60 min,玻璃化转变温度(Tg)为-8.91 ℃,具有优异的增塑性能及热稳定性能。     

Thermal stabilization of PVC by “plasticizer thiols”

Various new carboxylate esters containing one or more sulfhydryl groups are shown to be remarkably effective as both thermal stabilizers and plasticizers for poly(vinyl chloride) (PVC). These “plasticizer thiols” function well as primary stabilizers in the absence of metal‐containing additives when they are introduced at either a typical plasticizer level or a conventional stabilizer level. Their syntheses are straightforward and, in some cases, require only an acid‐catalyzed esterification performed with commercially available starting materials. Unlike typical thiols, the purified plasticizer thiols do not have offensive odors when their molecular weights are relatively high.     

Effects of epoxidized sunflower oil on the mechanical and dynamical analysis of the plasticized poly(vinyl chloride)

Epoxidized soybean oil (ESBO), is one of the most commonly used epoxides because of its typical combined roles as a plasticizer and heat stabilizer. In this study, a novel plasticizer of poly(vinyl chloride) (PVC) resins, epoxidized sunflower oil (ESO), was synthesized, and its performance was evaluated. ESO was designed to act as a coplasticizer and a heat stabilizer like ESBO. ESO is used as organic coplasticizer for plasticized PVC containing Ca and Zn stearates as primary stabilizers and stearic acid as lubricant. Di‐(2‐ethylhexyl) phthalate (DEHP), a conventional plasticizer for PVC, was partially replaced by ESO. Mechanical properties (tensile and shore D hardness) were investigated. The performance of ESO to ESB0 (20 g) for comparison, indicated that ESO could be used as secondary plasticizer for PVC in combination with DEHP. All mechanical and dynamical properties of plasticized PVC sheets varied with the oxirane oxygen of the ESO. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Palladium‐Catalysed Intramolecular Direct Arylation of 2‐Bromobenzenesulfonic Acid Derivatives

A palladium‐catalysed intramolecular direct arylation of 2‐bromobenzenesulfonic acid derivatives was found to proceed using 1 mol% of palladium acetate as the catalyst. The influence of the substituents on the phenol moiety of 2‐bromobenzenesulfonic acid phenyl esters reveals that electron‐donating substituents favour the reaction while electron‐withdrawing ones are unfavourable. The reactivity of sulfonamides was also studied and, in all cases, a selective activation at sp² C H vs. sp³ C H was observed. A sulfonamide bearing both phenyl and benzyl substituents on nitrogen gave selectively the six‐membered ring product.     

Molecular Basis for the Enantioselective Ring Opening of β‐Lactams Catalyzed by Candida antarctica Lipase B

Lipase B from Candida antarctica (CAL‐B) catalyzes the slow, but highly enantioselective (E>200), ring‐opening alcoholysis of two bicyclic and two 4‐aryl‐substituted β‐lactams. Surprisingly, the rate of the reaction varies with the nature of the alcohols and was fastest with either enantiomer of 2‐octanol. A 0.5‐g scale reaction with 2‐octanol as the nucleophile in diisopropyl ether at 60 °C yielded the unreacted β‐lactam in 39–46% yield (maximum yield is 50%) with ≥96% ee. The product β‐amino acid esters reacted further by polymerization (not isolated or characterized) or by hydrolysis due to small amounts of water in the reaction mixture yielding β‐amino acids (7–11% yield, ≥96% ee). The favored enantiomer of all four β‐lactams had similar 3‐D orientation of substituents, as did most previously reported β‐lactams and β‐lactones in similar ring‐opening reactions. Computer modeling of the ring opening of 4‐phenylazetidin‐2‐one suggests that the reaction proceeds via an unusual substrate‐assisted transition state, where the substrate alcohol bridges between the catalytic histidine and the nitrogen of the β‐lactam. Computer modeling also suggested that the molecular basis for the high enantioselectivity is a severe steric clash between Ile189 in CAL‐B and the phenyl substituent on the slow‐reacting enantiomer of the β‐lactam.     

Water‐Soluble Amphiphilic O‐(Carboxymethyl)cellulose Derivatives – Synthesis and Properties

Summary: Water‐soluble, partially hydrophobized derivatives of O‐(carboxymethyl)cellulose (CMC) were prepared by esterification of CMC in its ‘gel suspension’ form. The classical esterification method (A) using stearoyl chloride/pyridine as well as two unconventional methods based on reaction with mixed anhydrides (B) and transesterification with vinyl laurate (C) respectively, were compared in terms of the structural, molecular and performance properties of the obtained derivatives. The classical esterification and method B yielded water‐soluble simple fatty acid esters, whereas mixed acetic‐fatty acid esters were obtained by method C. In all cases, molecular degradation of CMC was observed. ¹H and ¹³C NMR spectroscopy of the acetyl‐lauroyl derivatives of CMC with a degree of esterification DS_E of 0.20 indicated a prevalence of the lauroyl groups (DS_Ac:DS_La = 0.03:0.17). Most of the water‐soluble derivatives exhibited excellent emulsifying efficiency. They represent polysaccharide‐based surfactants with effective anti‐redeposition properties as well as good washing power. Suitable derivatives can be prepared under mild reaction conditions by both unconventional methods which implies that they have potential as substitutes for the expensive and invasive conventional method.

Preparation of CMC derivatives.     

Investigations on esterification reactions of starches in 1‐N‐butyl‐3‐methylimidazolium chloride and resulting substituent distribution

The ionic liquid (IL) 1‐N‐butyl‐3‐methylimidazolium chloride ([C₄mim]⁺Cl^?) was used as solvent for different esterification reactions of the biopolymer starch. Therefore, maize starches with varying content of amylose were used. Different carboxylic acid anhydrides were applied to esterify starch with a degree of substitution (DS) in the range of 0.7–3.0. For example, starch acetates with the mentioned DS are accessible within 30 min at a 105°C‐reaction temperature. The DS distribution of starch acetates synthesized in IL was compared with the common starch acetate synthesis of Mark and Mehltretter. Also, a consideration of starch acetates and cellulose acetates synthesized in [C₄mim]⁺Cl^? is given. The starch esters were characterized by means of Raman spectroscopy for qualitative‐ and nuclear magnetic resonance spectroscopy for quantitative determination of the functionalization pattern. Moreover, the molecular mass distribution was determined after saponification by means of GPC‐MALLS. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and application of triglyceride plasticizers for poly(vinyl chloride)

A series of triglyceride plasticizers were prepared from glycerol, acetic acid, and benzoic acid through a two‐step reaction to develop potential uses of glycerol. The optimum reaction conditions were determined by the esterification of glycerol and acetic acid to produce glyceryl triacetate. When the molar ratio of glycerol to benzoic acid to acetic acid was 1:1:3.5, a novel plasticizer triglyceride mixture (GTM) was successfully synthesized; it had a good plasticizing effect on poly(vinyl chloride) (PVC). The elongation at break of PVC composites containing 80 phr GTM increased around 350%; the corresponding hardness (Shore D) and tensile strength decreased to around 35 D and 20 MPa, respectively. Moreover, the glass‐transition temperature (T_g) of PVC composites containing 40 phr GTM decreased to around 50°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enzymatic synthesis of fatty esters in 5‐caffeoyl quinic acid

The fatty esters of 5‐caffeoyl quinic acid were synthesized by direct esterification biocatalysed by an immobilised lipase obtained from Candida antarctica. Esterification yields (from 40 to 75%) depended on the carbon chain length of the fatty alcohols and whether or not solvent (2‐methyl 2‐butanol) was present in the reaction medium.     

磁性固体超强酸SO4^2-/TiO2-Fe3O4催化合成柠檬酸三辛酯

研究了以磁性固体超强酸SO4^2-/TiO2-Fe3O4为催化剂,以柠檬酸和正辛醇为原料催化合成无毒增塑剂柠檬酸三辛酯（trioctyl citrate,简称TOC）。考察了影响酯化率的各种因素,并对产品进行2#1-光谱分析。确定最适宜的反应条件是：反应温度为205℃,催化剂用量为1．75g,酸醇比为1：6．5,当反应时间2．Oh时,酯化率可达到97．3％。结果表明,磁性固体超强酸SO4^2-/TiO2-Fe3O4是合成柠檬酸三辛酯的优良催化剂,同时利用催化剂的磁性可将催化剂迅速分离。