Properties of starch‐based blend films using citric acid as additive. II

Starch/polyvinyl alcohol (PVA) blend films were prepared by using corn starch, polyvinyl alcohol (PVA), glycerol (GL), and citric acid (CA) as additives and glutaraldehyde (GLU) as crosslinking agent for the mixing process. The additives, drying temperature, and the influence of crosslinker of films on the properties of the films were investigated. The mechanical properties, tensile strength (TS), elongation at break (% E), degree of swelling (DS), and solubility (S) of starch/PVA blend film were examined adding GL and CA as additives. At all measurement results, except for DS, the film adding CA was better than GL because hydrogen bonding at the presence of CA with hydroxyl group and carboxyl group increased the inter/intramolecular interaction between starch, PVA, and additives. CA improves the properties of starch/PVA blend film compared with GL. TS, % E, DS, and S of film adding GLU as crosslinking agent were examined. With increasing GLU contents, TS increases but % E, DS, and S value of GL‐added and CA‐added films decrease. When the film was dried at low temperature, the physical properties of the films were clearly improved because the hydrogen bonding was activated at low temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2554–2560, 2006     

Properties of the crosslinked plasticized biodegradable poly(vinyl alcohol)/rambutan skin waste flour blends

Poly(vinyl alcohol) (PVOH)/rambutan skin waste flour (RWF) crosslinked films were successfully prepared by solution casting with glutaraldehyde (GLU) and hexamethylenetetramine (HMTA) and without crosslinker in the presence of glycerol as a plasticizer. The properties of cast films were evaluated by tensile testing, water absorption, and degradation behavior at different weight ratios of PVOH and RWF. The tensile results show that the PVOH/RWF films crosslinked with HMTA exhibited a slight improvement in the tensile strength and Young's modulus but a lower elongation at break than that of GLU-crosslinked films; this was attributed to the better crosslinking effect of HMTA, as shown by the Fourier transform infrared results. The HMTA-crosslinked film showed a lower water absorption and water vapor transmission rate as compared to the GLU-crosslinked and noncrosslinked films. A natural weathering test revealed that the addition of 1.5 wt % GLU and HMTA did not significantly affect the reduction in tensile properties, but the biodegradability test showed that the weight loss of noncrosslinked films was higher than those of the GLU- and HMTA-crosslinked films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚乙二醇改性聚乳酸/乙酰柠檬酸三丁酯复合薄膜的结构及性能

以聚乳酸（PLA）为基材、乙酰柠檬酸三丁酯（ATBC）为增塑剂、聚乙二醇（PEG）为增韧剂采用溶液共混法涂覆制备PLA复合薄膜。采用红外吸收光谱、热分析、X射线衍射、扫描电子显微镜及拉伸测试表征PLA复合薄膜的结构和性能。结果表明,适量的PEG改性PLA/ATBC复合薄膜后,使其拉伸强度从29.52 MPa增加到33.40 MPa,断裂伸长率从262 %增加到292 %,薄膜的柔韧性得到增强;PEG的端羟基与PLA的羰基发生缔合反应形成氢键,提高了PLA/ATBC复合薄膜的热稳定性和结晶度;观察90 d后的薄膜表面SEM图像,发现PEG改性后的PLA/ATBC复合薄膜表面没有龟裂纹的产生,延长了其使用寿命;加入微量的爽滑剂乙撑双硬脂酰胺（EBS）改善了PLA复合薄膜的相容性和加工性能。     

木质素聚氨酯薄膜合成条件及性能的研究

以麦草碱木质素、相对分子质量为300和 1000 的聚乙二醇(PEG)及多苯基甲烷多异氰酸酯(PAPI)为原料,以N,N-二甲基甲酰胺为溶剂,使用溶液浇注法固化成型工艺,制备了碱木质素聚氨酯薄膜。通过调整PEG1000与PEG300的比例提高了聚氨酯的力学性能。测定了木质素聚氨酯薄膜的弹性模量、拉伸强度和断裂拉伸率、耐撕裂度。实验结果表明,调节不同相对分子质量聚乙二醇在反应体系中的比例,可以显著提高成膜后的耐撕裂性能,改善由于加入木质素后聚氨酯薄膜过脆的缺点。当使用PEG1000与PEG300物质的量之比值为2.0,异氰酸酯指数为2.5,木质素加入量为 20%(质量分数)时,聚氨酯薄膜的弹性模量为 1.49 GPa、拉伸强度为 36.5 MPa、断裂拉伸率为 12.7%,耐撕裂度为 8460 mN,且成膜性能良好。     

PLA/chain‐extended PEG blends with improved ductility

Melt blending of polylactic acid (PLA) and a chain‐extended polyethylene glycol (CE‐PEG) have been performed in an effort to toughen the PLA without significant loss of modulus and ultimate tensile strength. The chain‐extended PEG was prepared with melt condensation of a low molecular weight PEG and 4,4′‐methylenebis(phenylisocyanate) (MDI) for enhancement of the molecular weight of PEG. The thermal and mechanical properties, miscibility and phase morphologies of blends were investigated. By using thermal and fracture surface analysis, the blends were found to be a partially miscible system with shifted glass transition temperatures. The addition of CE‐PEG leads to slight decrease in tensile strength and modulus, while the elongation at break is characterized by an important increase (540%), compared with neat PLA and PLA/PEG (low molecular weight PEG, M_n = 35,000). The relative ductility of PLA/CE‐PEG is 40 times higher than that of neat PLA. The brittle fracture of neat PLA was transformed into a ductile fracture by the addition of CE‐PEG. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Mechanical and barrier properties of polyvinyl chloride plasticized with dioctyl phthalate,epoxidized soybean oil,and epoxidized cardanol

Plasticized polyvinyl chloride (PVC) films were prepared by melt compounding and compression molding using epoxidized cardanol (EC), a biobased plasticizer and its plasticization effect was compared with epoxidized soybean oil (ESBO) and dioctyl phthalate (DOP). The mechanical, migration, thermal, and barrier properties of the plasticized films were compared. The effect of replacing DOP with EC on the properties of PVC films was also investigated. The tensile strength, elongation at break, tensile modulus and impact strength values of PVC/EC films were higher in comparison to PVC/DOP and PVC/ESBO films at a fixed plasticizer loading of 40 wt.%. Also, the films prepared with a mixture of DOP + EC showed higher tensile strength and elongation at break compared to that of films prepared with only DOP. The PVC/EC films showed good thermal stability and reduced oxygen transmission rate (OTR) compared to PVC/DOP films. The addition of graphene and nanoclay in the PVC/plasticizer system exhibited an increase in oxygen transmission. However, the oxygen barrier property of nano filler incorporated PVC/EC films was better than PVC/DOP films. All the films showed negligible water vapor transmission rate (WVTR).     

Three-stage interaction of dimethyl phthalate,dibutyl phthalate,and poly(vinyl acetate) with poly(methyl methacrylate)

The interaction of dimethyl phthalate (DMP), n-dibutyl phthalate (DBP), and poly(vinyl acetate) (PVAc) with poly(methyl methacrylate) (PMMA) was studied. Changes in the tensile strength, elastic modulus, and percentage elongation at break of the PMMA-additive films produced were followed using the Instron testing machine. The three additives produced (1) an initial plasticization, with a decrease in tensile strength and modulus and a possible increase in elongation; (2) an antiplasticization, with accompanying increase in tensile strength and modulus and an anomalous increase in elongation; and (3) a final plasticization, with a marked decrease in tensile strength and modulus and a definite increase in elongation of PMMA. The three effects were influenced by the molecular weight of the PMMA. A spacer effect by the interposition of the molecules of the additives between those of PMMA is proposed for the initial plasticization, while for the final plasticization, a lubrication action of the plasticizers on PMMA is suggested. Antiplasticization is explained by the formation of secondary bonds between the antiplasticizer and the PMMA molecules.     

Porous biodegradable polyester blends of poly(L‐lactic acid) and poly(ε‐caprolactone): physical properties,morphology, and biodegradation

Poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water‐extraction of PEG from solution‐cast phase‐separated PLLA‐blend‐PCL‐blend‐PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA‐blend‐PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07–1.4 GPa and elongation at break in the range 3–380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. Copyright © 2006 Society of Chemical Industry     

Improvement of the flame retardancy of plasticized poly(lactic acid) by means of phosphorus‐based flame retardant fillers

The aim of this study is to improve the flame resistance and toughness of poly(lactic acid) (PLA) with the addition of low amount of flame retardant fillers and plasticizer simultaneously. Poly(ethylene glycol) (PEG) was used as plasticizer for PLA. Ammonium polyphosphate, boron phosphate, and tri‐phenyl phosphate (TPP) were used as flame retardant additives. Among these flame retardant additives, boron phosphate was synthesized from its raw materials by using microwave heating technique. Characterization of PLA/PEG‐based flame retardant composites was performed by conducting tensile, impact, differential scanning calorimeter, thermal gravimetric analysis, scanning electron microscope, limiting oxygen index, and UL‐94 vertical burning tests. Mechanical tests showed that the highest tensile strength, impact strength, and elongation at break values were obtained with the addition of ammonium polyphosphate and TPP into PLA/PEG matrix, respectively. Scanning electron microscopy analysis of the composites exhibited that the more homogeneous filler distribution in the matrix was observed for TPP containing composite. The best flame retardancy performance was also provided by TPP when compared with the other flame retardant additives in the plasticized PLA‐based composites.     

不同形貌碳酸钙的制备及其对PVC薄膜力学性能的影响

选用偏钒酸铵、聚乙二醇、十六烷基三甲基溴化铵、焦磷酸钠十水和聚乙烯吡咯烷酮作为碳酸钙形貌控制剂,以氯化钙和碳酸钠为原料,用氯化法制备得到了片状、菱形、棒状、球状和立方体状5种不同形貌碳酸钙微粒,并研究不同形貌碳酸钙颗粒形态对软质聚氯乙烯（PVC）薄膜力学性能的影响。结果表明,不同形貌碳酸钙均提高了PVC薄膜的力学性能,PVC薄膜拉伸强度和断裂伸长率均提高显著;其中,棒状形貌碳酸钙对PVC薄膜力学性能的提高效果最好,拉伸强度达到了27.11 MPa;菱形碳酸钙改性PVC薄膜的断裂伸长率最高,为98.23 %。     

Improvement of Physico-Mechanical Properties of Radiation-Vulcanised Natural Rubber Latex Films by Adding Urea

The role of urea as an additive on the physico-mechanical properties of radiation vulcanised natural rubber latex (RVNRL) films was investigated. RVNRL films were prepared by the addition of urea with the concentration range 0–1.0 phr (parts per hundred rubber) and irradiated with various radiation doses (0–20 kGy). The concentration of urea and radiation doses were optimised and found to be 0.5 phr urea and 12 kGy radiation dose. Tensile strength, tear strength and cross-linking density of the rubber films increased with increasing the concentration of urea as well as radiation doses. The tensile and tear strengths of the films enhanced by 39 and 41%, respectively, at the optimum conditions. Elongation at break, permanent set and swelling ratio of the films decreased with increasing urea concentration and radiation doses until they attained approximately constant values.     

冷却温度对聚丙烯薄膜结晶、形态和拉伸性能的影响

采用示差扫描量热法(DSC)、广角X射线衍射(WAXD)和扫描电镜(SEM)对聚丙烯(PP)薄膜的结晶、形态进行了研究,并测试了薄膜的拉伸性能.结果表明:冷却水温度变化对生产PP薄膜的结晶、形态和拉伸性能有很大影响.在冬季,PP薄膜的结晶度更小,晶体尺寸更均一;但在夏季,PP薄膜的拉伸强度、杨氏模量和断裂伸长率分别提高45%、85%和94%.最后,通过数值模拟,得到了给定条件下相关冷却参数的合理数值.     

Preparation of resistant starch/poly(vinyl alcohol) blend films with added plasticizer and crosslinking agents

We report on the physical properties of films synthesized with native corn starch (NCS) and resistant starch (RS4) prepared with NCS. NCS and RS4/poly(vinyl alcohol) (PVA) blend films were synthesized with a mixing process and casting method. Glycerol (GL) and citric acid (CA) were used as additives. Glutaraldehyde (GLU) was used as a crosslinking agent of the films. RS4 was synthesized with sodium trimetaphosphate and sodium tripolyphosphate as a crosslinker. Then, the RS4 thus synthesized was confirmed by the pancreatin–gravimetry method, swelling power, differential scanning calorimetry, and X‐ray diffraction. The tensile strength, elongation, swelling behavior, and solubility of the films were measured. The results of the measurements indicated that the RS4‐added film was better than the NCS‐added film. In particular, the RS4/PVA blend film with CA as an additive showed physical properties superior to those of the other films. Also, the physical properties with GLU added as a crosslinking agent to the films were investigated. With increasing GLU contents, the tensile strength increased but the elongation, swelling behavior, and solubility values of the GL‐added and CA‐added films decreased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

PVC防水卷材的配方研究

研究了利用废旧软聚氯乙烯回收料(旧料)生产PVC塑料防水卷材的配方及其对卷材拉伸性能的影响。结果表明,PVC塑料卷材的拉伸强度和断裂伸长率随PVC树脂添加比例增加而提高,而相同添加量的SG-3型PVC树脂比SG-5型PVC树脂的拉伸性能高；在试验范围内,增塑剂用量增加,卷材的拉伸强度降低,伸长率先升后降；添加CPE能提高PVC卷材伸长率,但拉伸强度有所下降。当CaCO_3用量低于20份时,卷材的拉伸强度和伸长率随CaCO_3添加量增加而提高。PVC防水卷材的优选配方(质量份)：旧料85份,PVC树脂(SG-3型)15份,DOP 5份,CPE 3份,稳定剂(TLS)0．6份,其它助剂适量。     

PVC塑料供水管的配方研究

研究了CaCO3和ABS对硬聚氯乙烯（UPVC）复合体系的力学性能的影响。结果表明，在实验数据范围内，复合体系中加入ABS可以提高其冲击强度和弹性模量（少于5份），但材料的拉伸强度下降；在体系中加入适量的经表面处理的CaCO3能明显提高材料的冲击强度和断裂伸长率，当CaC03用量为12份时，其冲击强度和断裂伸长率分别提高了2．5倍和2.8倍左右，复合体系的弹性模量随CaCO3用量增加而提高。最优配方为：PVC100份（质量份，下同）、CaCO3 12份、ABS5份、钙锌复合稳定剂3．5份、其他助剂适量。以该配方生产的UPVC供水管各性能完全符合GB／T1000 2．1标准规定。     

玻纤表面处理用水性聚氨酯乳液合成与性能研究

采用异佛尔酮二异氰酸酯(IPDI)、聚醚二醇A、聚酯二醇B、亲水单体聚乙二醇PEG1000和二羟甲基丙酸(DMPA)等制备了阴/非离子型水性聚氨酯(WPU).讨论了亲水单体(PEG+DMPA)用量、异氰酸酯指数(R值)、聚醚/聚酯二醇配比等对乳液及胶膜性能的影响,并比较了使用不同表面处理剂的玻纤增强尼龙复合材料的性能....     

Effects of co‐plasticization of acetyl tributyl citrate and glycerol on the properties of starch/PVA films

Starch/polyvinyl alcohol (PVA) nanocomposite films by film blowing process were successfully obtained. Starch (1700 g), PVA (300 g), and organically modified montmorillonite (OMMT, 200 g) were blended and plasticized with acetyl tributyl citrate (ATBC) and glycerol (GLY) at weight ratios of 0/100, 5/95, 10/90, 15/85, 20/80, and 25/75. The structural, morphology, barrier, mechanical, and thermal properties of the films, as well as molecular interactions in the nanocomposites were analyzed. The 3.98 nm d‐spacing was the highest in starch/PVA nanocomposite films plasticized with ATBC/GLY ratio of 10/90. The film with ATBC/GLY (5/95) had the lowest WVP (3.01 × 10^?10 g m^?1 s^?1 Pa^?1). The longitudinal tensile strength (TS) of starch/PVA nanocomposite films gradually increased from 4.46 to 6.81 MPa with the increase of ATBC/GLY ratios. The T_g steadily increased from 49.2°C to 55.2°C and the ΔH of the nanocomposite films decreased from 81.77 to 51.43 J/g at the presence of ATBC. The addition of ATBC into GLY plasticized starch/PVA/OMMT system enhanced the intermolecular interaction in the nanocomposites. This study proved that ATBC was an excellent compatibilizer in the preparation of starch/PVA/OMMT nanocomposite films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42544.     

Properties and weldability of plasticized polylactic acid films

The objectives of the presented work were to investigate films based on polylactic acid (PLA) and polyethylene glycol (PEG) in order to improve ductility and weldability of PLA films. The effect of plasticizer amount on the thermal, rheological, and mechanical properties of PLA plasticized films was investigated. The PEG content does affect the glass transition and the cold crystallization temperature of PLA in blends, while the melting temperature was not affected by the addition of PEG. The complex viscosity of the neat PLA granules and of plasticized films showed strong temperature and angular velocity dependence. The Young's modulus and tensile strength of plasticized films were improved with increasing plasticizer concentration, while the elongation at break stays rather constant. Plasticized PLA films were furthermore heat welded. These investigations showed that plasticized PLA films can be welded by heat welding. The obtained weld strength is strongly depending on the PEG amount as well as on selected welding parameters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40394.     

Plasticized poly(lactic acid) with low molecular weight poly(ethylene glycol): Mechanical,thermal, and morphology properties

Poly(lactic acid) PLA was plasticized with low molecular weight poly(ethylene glycol) PEG‐200 to improve the ductility of PLA, while maintaining the plasticizer content at maximum 10 wt%. Low molecular weight of PEG enables increased miscibility with PLA and more efficient reduction of glass transition temperature (T_g). This effect is enhanced not only by the low molecular weight but also by its higher content. The tensile properties demonstrated that the addition of PEG‐200 to PLA led to an increase of elongation at break (>7000%), but a decrease of both tensile strength and tensile modulus. The plasticization of the PLA with PEG‐200 effectively lowers T_g as well as cold‐crystallization temperature, increasing with plasticizer content. SEM micrographs reveal plastic deformation and few long threads of a deformed material are discernible on the fracture surface. The use of low molecular weight PEG‐200 reduces the intermolecular force and increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4576–4580, 2013     

Preparation of UV-curable PEG-modified urethane acrylate emulsions and their coating properties. II. Effect of chain length of polyoxyethylene

To prepare self-emulsifiable urethane acrylate, poly(ethylene glycol)-modified urethane acrylates (PMUA), containing polyoxyethylene chains as a terminal group were synthesized by the reaction of a residual isocyanate group with poly(ethylene glycol) (PEG). Five types of PMUA were synthesized using five types of PEG having different molecular weight. As the chain length of polyoxyethylene of PMUA increased, the thermal stability of their emulsions improved and the tensile strength of their UV-cured films were also increased. For PMUA600 prepared using PEG600, the thermal stability of the emulsion and tensile strength of UV-cured film were relatively low. However, the emulsions of PMUAs which were synthesized using PEG2000, PEG4000, and PEG6000 were stable with increasing temperature and the tensile strength of their cured films was greater than that of PMUA 600. When PMUA600 was mixed with PMUA2000, PMUA4000, and PMUA6000, the thermal stability of the emulsions of mechanical properties of their UV-cured films were improved greatly. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2657–2664, 1997