异山梨醇基增塑剂对聚乳酸性能及结晶行为的影响

以异山梨醇和辛酰氯为原料合成了一种生物基增塑剂二辛酸异山梨醇酯(SDO),然后将其与聚乳酸(PLA)进行熔融共混。DSC分析表明PLA的玻璃化转变温度(t_g)随着SDO的增加而降低。此外,用热重分析仪(TG)研究了SDO对PLA的热稳定性的影响。并且,对PLA和PLA/SDO共混物的力学性能进行了测试,结果表明,SDO的加入能够使PLA由脆性材料转变为韧性材料。最后,用偏光显微镜研究了SDO对PLA结晶行为的影响,随着SDO含量的增加,PLA球晶数目逐渐减少,但是PLA球晶的尺寸逐渐变大。     

环保增塑剂异山梨醇二正己酸酯在聚乳酸中的应用

将异山梨醇二正己酸酯(DHDIC)用于与聚乳酸(PLA)的共混增塑,通过拉伸、旋转流变、差示扫描量热仪(DSC)等测试手段考察共混物的力学性能、流变学性能以及加工性能。随着增加DHDIC的含量,PLA/DHDIC共混物的拉伸强度降低,断裂伸长率升高,表现出典型的橡胶态塑料的性质;共混物的玻璃化转变温度也大幅降低,使材料具有良好的加工性能,DHDIC能被用作PLA优良的环保增塑剂。     

生物基增塑剂异山梨醇酯的研究

以异山梨醇为原料合成了一种生物基增塑剂异山梨醇酯,通过与传统增塑剂邻苯二甲酸二辛酯(DOP)和对苯二甲酸二辛酯(DOTP)对比,考察了其聚氯乙烯(PVC)制片的应用性能.结果表明,合成的异山梨醇酯在PVC制片中具有更优良的力学性能、耐抽出性、耐挥发性及相容性,异山梨醇酯作为生物基增塑剂可替代传统增塑剂的DOP和DOTP...     

复合增塑剂改性PLA共混物的结构与性能

采用HM-128,HM-529两种增塑剂复配对聚乳酸(PLA)进行熔融共混改性,研究增塑剂用量对共混物的流变性能、拉伸性能和微观形态结构的影响,筛选增塑剂复配最佳配比和用量.结果表明,确定HM-128与HM-529质量比为1:1保持不变,随着增塑剂用量增加,共混物的平衡转矩和拉伸强度降低、断裂伸长率增加、撕裂强度呈先增加后减小的趋势,淬冷断面由平整变为粗糙;在复合增塑剂总质量分数16%不变的情况下,随着复配增塑剂中HM-529含量的增加,共混物的平衡转矩增大、断裂伸长率提高,当HM-128/HM-529质量比=1/1时,共混物的拉伸强度、断裂伸长率和撕裂强度分别为35.6 MPa,209.2%和30.6 N/cm,淬冷断面非常粗糙,获得了良好的增韧效果,共混物的综合性能最理想.     

聚乳酸增塑体系熔体流动性及力学性能研究

通过熔融共混法,分别以乙酰柠檬酸三丁酯(ATBC)、己二酸二丁基二甘酯(增塑剂A)、异山梨醇硬脂酸酯(增塑剂B)、癸二酸二丁酯(DBS)为增塑剂,以丙烯酸型抗冲改性剂为增韧剂,制备了增塑聚乳酸(PLA)和复配增塑增韧PLA,研究了复配改性PLA的熔体流动性和力学性能,考察了增韧剂对PLA增塑体系的影响。结果表明:增塑剂A增塑PLA的综合性能较好;增韧剂可有效降低材料的熔体流动速率,提高材料的缺口冲击强度和断裂伸长率,但其拉伸强度有所降低。     

增塑剂对PHBV/PBS共混物性能的影响

分别以柠檬酸三乙酯(TEC)、聚乙二醇(PEG)作为聚β-羟基丁酸/戊酸酯(PHBV)和聚丁二酸丁二酯(PBS)共混时的增塑剂,通过熔融加工制得PHBV/PBS共混物。利用熔体流动速率仪、差示扫描量热仪、X射线衍射仪)、万能材料试验仪、扫描电子显微镜等研究PHBV/PBS共混物的熔体流动速率、热性能、晶胞结构、力学性能、相形态等性能。结果表明,随着增塑剂添加量的增加,共混物性能发生显著变化。当PEG和TEC用量均为10份(质量份)时,共混物的熔体流动速率分别增大到纯共混物的约3倍和1.8倍;PEG和TEC均使共混物的拉伸断裂伸长率先增加后降低,其中PEG和TEC的含量分别为2.5份和10份时,共混物有最大断裂伸长率;共混物的结晶(Tc)和熔融温度(Tm),随着两种增塑剂量增加均略有下降。扫描电镜照片表明两种增塑剂对共混物中两相的分散起到促进作用。     

小分子增塑剂对聚氯乙烯共混体系相容性的影响

采用熔融共混法分别将聚氯乙烯(PVC)、增塑剂邻苯二甲酸二辛酯(DOP)和α-甲基苯乙烯-丙烯腈共聚物(α-MSAN)或聚甲基丙烯酸甲酯(PMMA)进行熔融共混,制备了一系列PVC/α-MSAN/DOP和PVC/PMMA/DOP共混物,利用动态黏弹谱仪、扫描电子显微镜研究了共混体系的相容性和相形态。结果表明,PVC/α-MSAN和PVC/PMMA共混物均为完全相容体系,引入增塑剂DOP后,PVC/PMMA共混物仍为相容体系,而对于PVC/α-MSAN共混物,随着DOP含量的增加,共混体系的相分离愈趋明显;最后阐明了小分子化合物对聚合物共混体系相容性的影响机制。     

异山梨醇基增塑剂与聚乳酸相容性对其结晶形态的影响初探

采用基团贡献法计算增塑剂的Hansen溶解度参数，并推测增塑剂与聚乳酸（PLA）的相容性，通过ASTM D 2383—2019标准验证该推测的正确性。采用偏光显微镜观察异山梨醇基增塑剂加入后PLA的结晶形态，从熔体流动性能的角度探究相容性对PLA结晶形态的影响。结果表明：二丁酸异山梨醇酯、乙酰化辛酸异山梨醇酯增塑剂的Hansen溶解度参数分别为19.6 (MJ/m3)1/2、16.2 (MJ/m3)1/2，推测二丁酸异山梨醇酯与PLA的相容性良好。增塑剂与PLA的相容性影响其结晶形态。经二丁酸异山梨醇酯增塑改性后，PLA的晶粒数量增多且晶粒尺寸减小，能够观察到明显的消光黑十字现象。     

3D打印用聚氯乙烯多相复合体系的开发

采用高分子类增塑剂乙烯-乙酸乙烯酯共聚物(EVM)替代聚氯乙烯(PVC)传统增塑剂,制备出具有双连续相结构的PVC/EVM/聚乳酸(PLA)共混物.通过热分析、流变学测试及微观形貌观察等研究了共混物结构与性能间的关系.结果表明,随着填料蒙脱土(OMMT)或碳纳米管的加入,PVC/EVM/PLA共混物的热分解温度和体系燃...     

添加剂对PVC/ABS共混物热稳定性及力学性能的影响

通过熔融共混的方法制备了热稳定剂不同含量和增塑剂不同含量的聚氯乙烯/丙烯腈-丁二烯-苯乙烯(PVC/ABS)共混物,采用热失重法和刚果红试纸法对共混物的热稳定性进行了研究,并对其力学性能进行了测试.结果表明:随着热稳定剂用量的增加,PVC/ABS共混物的热稳定性提高,但力学性能却下降,热稳定剂的用量不应超过5份;热稳定剂的加人影响ABS的热稳定性,但具体的作用机理还不清楚;随着增塑剂邻苯二甲酸二辛酯(DOP)用量的增加,PVC/ABS共混物的热稳定性提高,但力学性能下降,DOP的用量不应超过15份;熔体流动速率测定和透射电镜分析表明,DOP能够改善PVC/ABS共混物的加工流动性,提高热稳定剂的分散性,从而提高共混物的热稳定性。     

Mechanical properties of PVC/SBR blends compatibilized by acrylonitrile-butadiene rubber and covulcanization

The mechanical properties of poly(vinyl chloride) (PVC)/styrene-butadiene rubber (SBR) blends compatibilized by acrylonitrile-butadiene rubber (NBR) were studied. A sulfur curing system was employed to crosslink the rubber of the blends. In the case of the blends without any curing agents, an increase in NBR content did not improve the tensile strength and elongation-at-break. However, a significant improvement in the mechanical properties was observed when NBR was added as a compatibilizer and the blend was vulcanized. In the PVC/NBR/SBR (50/10/40) blends, the tensile strength and elongation-at-break increased with an increase in sulfur concentration. This improvement was attributed to covulcanization between NBR and SBR. The fracture toughness of PVC/NBR/SBR (50/10/40) blends was characterized by the critical strain energy release rate, G_c. In the case of the PVC/NBR-29/SBR (50/10/40) blends, an increase in sulfur concentration resulted in a dramatic increase in G_c. However, the G_c value of PVC/NBR-40/SBR (50/10/40) blends decreased with an increase in sulfur concentration owing to the brittle behavior of one of the blend components—the PVC/NBR-40 (50/10) phase.     

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.     

全硫化超细粉末橡胶对PVC-U力学性能及形态的影响

研究了未增塑聚氯乙烯／粉末橡胶共混物的力学性能和形态特征。研究发现，随粉末橡胶用量增大，共混物的冲击强度先有所降低然后逐渐上升。实验结果和电镜图像表明：粉末橡胶基本粒子均匀分散的效果是影响共混物冲击韧性高低的重要因素；环氧化天然橡胶有促进粉末橡胶分散、改进增韧效果的作用。基本断裂功方法的研究结果表明，共混物的比基本断裂功随粉末橡胶用量增多而降低，比非基本断裂功则随之而升高，且断裂功的变化主要表现在材料屈服之前。     

环氧腰果酚基磷酸二苯酯增塑剂的合成及塑化PVC

以腰果酚为原料合成了环氧腰果酚基磷酸二苯酯(ECPhP),采用核磁共振氢谱和核磁共振碳谱对产物结构进行了表征,并将ECPhP与聚氯乙烯(PVC)进行共混,对共混试样的力学性能、热稳定性、相容性和加工流变性进行了分析,并对增塑剂迁移性、抽出性和挥发性损失进行了考察,研究ECPhP作为主增塑剂及辅助增塑剂的增塑效果,并与石油基增塑剂——对苯二甲酸二辛酯(DOTP)进行比较。结果表明,所合成的ECPhP增塑剂具有较好的增塑效果及热稳定性,与单独使用DOTP相比,增塑剂中ECPhP的含量由0增加到20%(占增塑剂总质量百分比)时,共混体系的玻璃化转变温度由47.16℃降低到43.94℃;10%和50％质量损失温度分别提高了10.4℃和9.5℃;断裂伸长率提高,体系柔韧性得到提高;动态热稳定时间由9.55 min延长到30.06 min,加工稳定性更好;抽出性损失降低,增塑剂在塑化体系中的稳定性得到显著提高。该腰果酚基增塑剂可作为PVC的优良辅助增塑剂使用。     

Blends of PVC and epoxidized liquid natural rubber: Studies on impact modification

Liquid natural rubber of different molecular masses L‐LNR, and H‐LNR were subjected to varying degree of epoxidation (L‐ELNR‐10, L‐ELNR‐20, L‐ELNR‐30, L‐ELNR‐40, L‐ELNR‐50, H‐LNR‐20, and H‐LNR‐50) and the products were incorporated into PVC at various compositions by the solution blending method. These blend systems were subjected to tensile testing, tensile impact measurements, and SEM studies. It was observed that blends with L‐ELNR‐20 showed highest impact strength modification, followed by L‐ELNR‐10 and L‐ELNR‐30. High impact properties showed by these blends are attributed to the optimum level of compatibility existing between the blend components. Tensile impact fracture studies revealed that the failure pattern for this blend system is intermediate between the brittle fracture of rigid PVC and ductile fracture of PVC/L‐ELNR‐50 samples. Blends up to 30 mol % of epoxidation showed partially compatible heterogeneous nature exhibiting domain morphology. Blends of liquid rubber with higher degree of epoxidation showed deterioration in tensile strength, modulus, yield strength, and tensile impact strength due to plasticization of PVC caused by the higher polar interaction between PVC chains and the oxirane rings. Effect of ELNR molecular weight was studied and it is found that the impact modification is higher for the L‐ELNR blends compared to the H‐ELNR blends. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Compatibility between PVC and plasticizer blends and its relation with processing

The compatibility of suspension PVC with various plasticizer blends was determined by means of calculated compatibility predictors, such as solubility parameters and polarity parameters, as well as actual measurements of compatibility. Then, with a torque rheometer, the temperature at the fusion peak was obtained for various PVC/plasticizer blend compositions. Finally, empirical equations were derived to relate compatibility parameters with the temperature at the fusion peak, predicting the effect of plasticizer blend on processability.     

Plastification of poly(vinyl chloride) by polymer blending

Blends of poly(vinyl chloride) (PVC) with different copolymers have been studied to obtain a plasticized PVC with improved properties and the absence of plasticizer migration. The copolymers used as plasticizers in the blends were acrylonitrile butadiene rubber, ethylene vinyl acetate (EVA), and ethylene-acrylic copolymer (E-Acry). Blends were studied with regard to their processing, miscibility, and mechanical properties, as a function of blend and copolymer composition. The results obtained were compared with those of equivalent compositions in the PVC/dioctyl phthalate (DOP) system. Better results than PVC/DOP were obtained for PVC/acrylonitrile butadiene rubber blends. The plasticizing effect on PVC of EVA and E-Acry copolymers was similar to that of DOP. It is shown that crosslinking PVC/E-Acry blends or increasing the vinyl acetate content in PVC/EVA blends, are alternatives that can increase the compatibility and mechanical properties of these blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1303–1312, 2000     

双马来酰亚胺／聚醚酰亚胺共混体系的增韧改性研究

研究了有机硅烷偶联剂对双马／聚醚酰亚胺共混体系的增容增韧作用。结果表明,加入有机硅烷偶联剂KH-550、KH-560、偶联剂B后,共混物断裂韧性（G1c）均有大幅度提高,其中偶联剂B增韧效果最佳;当B的添加量为2．5份时,体系的断裂韧性最大,达到1053J／m^2,为改性前的3．9倍,体系的微观形貌（SEM）由改性前的两相结构转变为双连续相结构。     

Acrylonitrile-styrene-acrylate particles with different acrylonitrile contents for improving the toughness of poly(vinyl chloride) resin

Poly(butyl acrylate) grafted styrene and acrylonitrile copolymer (PBA-g-SAN, ASA) with core–shell structures were prepared by emulsion polymerization technology to improve the toughness of the poly(vinyl chloride) (PVC). The mechanical properties of the PVC/ASA blends were investigated. The notch impact strength of the PVC/ASA blend could reach 1200 J/m when the 13 phr ASA was added to the PVC. This was several times more than pure PVC resin. Scanning electron microscopy analysis results indicated that the improvement in impact strength of the PVC/ASA blend was attributed to shear yielding induced by ASA particles. Additionally, subtle changes in the ratio of monomers in the shell layer led to significant fluctuations in the mechanical properties of the composites. Dynamic mechanical analysis showed that the intermolecular interaction forces between ASA particles and PVC resins played a key role in improving the toughness of PVC/ASA blend.     

High‐density polyethylene/ultrahigh‐molecular‐weight polyethylene blend. I. The processing,thermal, and mechanical properties

Various blend ratios of high‐density polyethylene (HDPE) and ultrahigh‐molecular‐weight polyethylene (UHMWPE) were prepared with the objective of determining their suitability as biomaterials. Although the presence of HDPE in the blends enabled melt processing, the presence of UHMWPE helped to improve the toughness of the resulting blends. The processability of the blends was investigated with the Brabender torque, which was used as an indication of the optimum blend conditions. The blends were characterized with differential scanning calorimetry. The mechanical tests performed on the blends included tensile, flexural, and impact tests. A 50:50 (w/w) blend yielded optimum properties in terms of the processability and mechanical properties. The tensile property of the 50:50 blend was intermediate between those of HDPE and UHMWPE, but the strain at break increased 200% in comparison with that of both neat resins. The energy at break of the 50:50 blend revealed an improvement in the toughness. The fracture mechanism was also investigated with scanning electron microscopy. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 413–425, 2005