PCL/PPC共混膜性能研究

目的提高聚己内酯(PCL)薄膜对氧气及水蒸汽的阻隔性。方法利用双螺杆挤出机,对PCL与聚碳酸亚丙酯(PPC)进行共混挤出制备薄膜材料,并对PCL/PPC共混膜的相容、热学、阻隔及力学等性能进行测量。结果当PPC含量较少或较多时,PCL与PPC具有一定的相容性,而在中间含量时出现了相分离;PCL/PPC薄膜对氧气的透过系数和水蒸气的透过率随着PPC含量的增加而降低;PPC的加入提高了PCL的强度及模量,在共混比例较小时,共混膜有相对较好的抗撕裂性能。结论添加适量的PPC能使PCL表现出更好的氧气和水蒸汽阻隔性及较好的力学性能。     

PLA/PCL共混膜的制备及性能研究

目的研究PCL含量对PLA/PCL共混包装膜性能的影响,以改善PLA的韧性。方法将不同质量比的PLA和PCL树脂均匀混合,而后熔融挤出吹膜制得PLA/PCL共混膜。对制得的共混膜进行力学性能测试,获得拉伸强度和断裂伸长率,再通过扫描电镜分析观察其微观断面,采用DSC测试分析其熔融结晶行为,通过氧气透过性能和透湿性能的测试获得其阻隔性能。结果通过扫描电镜与红外光谱发现,PLA与PCL为两相结构,界面不相容;力学性能显示当PCL的质量少于20%时,对PLA的增韧效果不明显;当PCL的质量为50%时,PLA的断裂伸长率从2.9%提高到290%;DSC结果发现,PCL的加入有助于降低PLA的玻璃化转变温度,提高结晶度;阻隔性能结果表明,随着PCL质量比的增大,共混膜的氧气透过系数和透湿系数下降,阻隔性得到提高。结论 PCL的加入能提高PLA的韧性,当PCL与PLA质量比为3∶7时,共混膜具有最佳的性能。     

改性木质素/PBAT复合包装膜的研究

目的 将硅烷化木质素（SAL）与聚己二酸/对苯二甲酸丁二酯（PBAT）共混制备包装性能更为优良的SAL/PBAT复合包装膜,使其在包装领域应用更广。方法 通过对木质素进行硅烷化改性,以咪唑作为中间体,将叔丁基二甲基氯硅烷（TBDMSCl）接枝到木质素的羟基上制备SAL,并将SAL与PBAT进行熔融共混吹塑成膜,探讨其对包装膜的力学和阻隔等性能的影响。结果 与纯PBAT膜相比,SAL/PBAT复合包装膜拉伸强度提高了31.0%,断裂伸长率降低了37.4%,弹性模量提高了529.7%,氧气透过率降低了39.4%,水蒸气透过率降低了42.4%。结论 改性木质素与PBAT复合能够产生协同效应,可以有效改善SAL/PBAT复合包装膜的力学和阻隔性能。     

Mechanical and Barrier Properties of LLDPE/Chitosan Blown Films for Packaging

The blends of linear low‐density polyethylene and chitosan were prepared by using a two‐step melt‐compounding process and then were made into blown films for packaging. LLDPE‐g‐MAH was used as compatilizer to enhance the dispersing effect of chitosan in the matrix. Fourier transform infrared spectra and scanning electron microscope images of the blown films confirmed that there were new amide bonds formed between chitosan and LLDPE‐g‐MAH. The mechanical and barrier properties of the LLDPE/chitosan blown films were investigated. The result indicated that the breaking strength and elongation decreased as the chitosan content increased. In addition, the water vapour permeability of the blend films could be improved up to 200% with the increment of chitosan content, and the oxygen permeability decreased about 20% compared with the films without chitosan. It was found that LLDPE‐g‐MAH had obvious effects on the mechanical properties and oxygen permeability apart from the water vapour resistance. Copyright © 2015 John Wiley & Sons, Ltd.     

Technofunctional Properties of Films Made From Ethylene Vinyl Acetate/Whey Protein Isolate Compounds

One challenge faced by the plastics industry is that crude oil will become scarcer and more expensive in the future. Furthermore, an increase in plastic waste is leading to a strongly growing demand for sustainable alternatives to traditional, crude oil‐based polymers in the packaging sector. The aim of this study was to investigate the influence of the incorporation of whey protein isolates (WPIs) on the technofunctional properties of ethylene vinyl acetate (EVA) films. The compounding EVA with WPI was conducted in a co‐rotating twin‐screw extruder at varying processing temperatures. WPI and hydrolysed WPI with a degree of hydrolysis of 10% were used up to 35% (w/w) as filler. The tensile strength and elongation at break of the resulting EVA‐based films decreased significantly with increasing filler content. Because of the hydrophilicity of WPI, the water vapour permeability of the films increased. Advantageously, the oxygen barrier was enhanced by 50–80% compared with that of pure EVA films, which offered the potential of using whey proteins as a filler in compounds for packaging materials for their oxygen barrier properties. In addition, this study provides a promising perspective on the thermoplastic processing of whey protein formulations in the future. Copyright © 2013 John Wiley & Sons, Ltd.     

Mechanical and thermal behaviour of biodegradable composites based on polycaprolactone with pine cone particle

Polycaprolactone (PCL) was reinforced with natural fibres as they not only permit a substantial reduction of the material costs, but also play a role as reinforcement in mechanical properties. This work was focused on the estimation of mechanical and thermal behaviour based on PCL and Pine Cone particles (PCP) filler at different weight percentages (0, 5, 10, 15, 30 and 45 wt%). Tests results indicated considerable improvement in mechanical properties, corresponding to a gain in impact strength and % elongation of 6 and 9.2% at 15 wt% particle loading, respectively. Some decrease in thermal stability was observed for composites with increasing filler content where as composite at 15% PCP was not significantly affected. Lower melting and crystallization enthalpies and higher crystallinity values were obtained for bio-composites compared with neat PCL. Some decrease in thermal stability and increase in oxygen and water vapour barrier properties were also observed for composites with increasing filler content.     

SiOx/PET复合薄膜的力学性能及阻隔性能

目的基于氧化硅(SiO_x)镀层优异的性能,研究不同厚度的SiO_x层对SiO_x/PET复合薄膜力学性能和阻隔性能的影响,以期得到性能较优的SiO_x/PET复合薄膜。方法以自制的聚对苯二甲酸乙二醇酯(PET)薄膜为基材,采用等离子体增强化学气相沉积法沉积得到SiO_x层厚度分别为40,150,230,320 nm的SiO_x/PET复合薄膜,并进行傅里叶变换红外线光谱分析、力学性能和阻隔性能测试,以及薄膜表观形貌分析。结果沉积SiO_x层后,SiO_x/PET复合薄膜拉伸强度和断裂伸长率随SiO_x层厚度的增大先增大后减小,氧气透过率和水蒸气透过率则出现明显衰减而后逐渐平缓的趋势。SiO_x层厚度达150~230 nm时,复合薄膜的力学性能和阻隔性能表现较优,拉伸强度、断裂伸长率、氧气透过率以及水蒸气透过率分别提高了约25.0%,20.9%,79.3%,77.3%。结论适宜厚度的SiO_x层可以使得SiO_x/PET复合薄膜同时具备较优的力学性能和阻隔性能。     

番茄皮渣/玉米淀粉膜的制备与研究

目的以番茄皮渣为原料,玉米淀粉为增稠剂,甘油为增塑剂,采用流延法制备番茄皮渣/玉米淀粉膜。方法研究番茄皮渣、玉米淀粉和甘油含量对番茄皮渣/玉米淀粉膜性能的影响。结果随着番茄皮渣含量的增加,番茄皮渣/玉米淀粉膜的抗张强度和氧气透过率增大,断裂伸长率和水溶性减小,经番茄皮渣/玉米淀粉膜包裹的油脂的过氧化值减小,抗氧化性提高;随着淀粉含量的增加,番茄皮渣/玉米淀粉膜的抗张强度增大,断裂伸长率和水溶性减小,氧气透过率先减小后增大,经番茄皮渣/玉米淀粉膜包裹的油脂的过氧化值变化不大;随着甘油含量的增加,番茄皮渣/玉米淀粉膜的抗张强度减小,断裂伸长率、氧气透过率和水溶性增大,经番茄皮渣/玉米淀粉膜包裹的油脂的过氧化值变化不大。结论番茄皮渣/玉米淀粉膜的适宜制备工艺条件为番茄皮渣质量分数为2.5%~3%、玉米淀粉质量分数为3%~4%、甘油质量分数为1.5%~2%。     

SiO2含量与粒径对PLA/SiO2复合膜性能的影响

目的 为了提高聚乳酸材料的力学性能和气体阻隔性,选择二氧化硅为共混材料,通过改变二氧化硅的粒径和含量,研究SiO2对SiO2/PLA复合膜性能的影响.方法 用流延法制备二氧化硅/聚乳酸(SiO2/PLA)复合膜.采用力学性能测试、结晶性测试、热稳定测试和透氧、透水蒸汽测试等分析手段对制备的复合膜进行力学性和阻隔性的表征.结果 在PLA材料中添加适量的SiO2对复合膜的拉伸强度和弹性模量会有增强作用,并且粒径越小,增强效果越明显;粒径为50 nm,质量分数为2％时复合膜表现出更佳的力学性能.同时,随着SiO2含量的增加,氧气透过系数呈先降低后升高的趋势,在SiO2质量分数为2％时透过系数最小,复合膜的氧气阻隔性最好;不同粒径不同含量的SiO2透湿性测试结果表明,SiO2粒径为50 nm,质量分数为2％时复合膜的阻隔性效果最好.结论 二氧化硅的加入能够提升聚乳酸的弹性模量和阻隔性,并且二氧化硅的粒径和不同添加量对复合膜的性能有很大影响.     

氧化纳米纤维素增强再生纤维素全纤维素复合薄膜的制备及性能

以2,2,6,6-四甲基哌啶-氮-氧化物(TEMPO)氧化松木粉纳米纤维素(TOCNs)为增强相、α-纤维素粉制备再生纤维素(RC)为基体,采用溶胶-凝胶法制备氧化纳米纤维素增强再生纤维素(TOCNs/RC)全纤维素复合薄膜。对不同TOCNs添加量下TOCNs/RC全纤维素复合薄膜的力学性能、光学性能、氧气阻隔性能和热稳定性能进行研究,并通过FTIR、SEM、TEM、XRD和流变仪对TOCNs和TOCNs/RC全纤维素复合薄膜的结构、形貌及纤维素溶液流变性能进行表征。结果表明,TOCNs添加量对TOCNs/RC全纤维素复合薄膜的力学性能有显著影响,当TOCNs添加量(与纤维素基体的质量比)为1.0%时,TOCNs/RC全纤维素复合薄膜的拉伸强度和断裂能分别可达134.3 MPa和21.51 MJ·m?3,具有最佳的综合力学性能;TOCNs/RC全纤维素复合薄膜的透光率随TOCNs添加量的增加而下降,雾度随TOCNs添加量的增加而增大,但仍保持较高的透光率(>85%)和较低的雾度(<14%);TOCNs/RC全纤维素复合薄膜还具有优异的氧气阻隔性,TOCNs添加量为1.6%时,其透氧系数仅为1.47×10?17cm3·cm/cm2·s·Pa。TOCNs/RC全纤维素复合薄膜有优于一般塑料薄膜的拉伸强度和氧气阻隔性,并有可媲美于塑料薄膜的透明度,可作软包装复合材料的强度层和阻隔层,在绿色高性能包装材料领域具有广阔的应用前景。      

POSS对壳聚糖膜的阻湿与拉伸性能的影响

目的研究以四甲基铵基笼形聚倍半硅氧烷(Octa TMA POSS)为填料,制备壳聚糖基复合膜,对壳聚糖薄膜的水蒸气阻隔性能和力学性能进行改善。方法采用溶液共混流延法制备复合膜,测定其水蒸气透过系数、表面接触角、溶胀度、溶解度、吸附等温曲线、拉伸性能、成膜液流变性能、微观形貌和X射线衍射等。结果笼形聚倍半硅氧烷的加入可提高复合膜对水分子的阻隔性,尤其是质量分数为3%时,其水蒸气透过系数下降了15.9%。同时,壳聚糖薄膜的力学性能也得到改善,在质量分数低于5%时,壳聚糖薄膜的抗拉强度、弹性模量可同时得到提高。结论四甲基铵基笼形聚倍半硅氧烷的加入可改善壳聚糖薄膜的阻湿性能和力学性能,可大大提升其在食品包装领域的应用潜力。     

Pumpkin seed oil cake/polyethylene film as new food packaging material,with perspective for packing under modified atmosphere

Biopolymer packaging materials show increasing perspective in food packaging. Main limitation remains their high water sensitivity and poor water vapour barrier properties, compared to non polar materials of synthetic origin like polyethylene. In this paper, biopolymer layer obtained from by‐product of oil industry (pumpkin seed oil cake) was laminated on polyethylene in order to obtain new packaging material that would preferably combine water barrier properties of polyethylene and oxygen barrier properties of biopolymer composite material and perform satisfactory mechanical properties. Obtained two‐layer material showed good barrier properties for water vapour (7–8 g/m² 24h), as well as oxygen (12–45 cm³/m² 24h) and light. In addition, mechanical and water sensitivity tests were performed and results showed that new material inherited biopolymer film water sensitivity and mechanical properties with slight improvement. Measured tensile strength and elongation at break was 2–4 MPa and 150–250% in transversal direction and 6–8 MPa and 100–150% in longitudinal direction. Packing in modified atmosphere assay showed that new material can be used for this purpose with good control of oxygen concentration, while packing under increased concentration of CO₂ could be performed for shorter storage period. New two layer material shows promising properties for sensitive food packing under modified atmosphere conditions with reduced use of synthetic, oil‐based materials.     

TiO2/淀粉/PCL共混材料的制备及表征

目的以玉米双磷脂淀粉和聚己内酯（PCL）为原料,甘油为增塑剂,改性纳米TiO₂为抗菌剂,制备一种具有抗菌性能的可降解材料,并对不同淀粉/PCL质量比和不同纳米TiO₂添加量下制得的共混材料进行表征,以探究最佳共混比例。方法将不同质量比的淀粉/PCL混合,添加一定量的甘油作为增塑剂,并添加不同含量的纳米TiO₂作为抗菌剂,熔融共混并热压成型,利用力学、红外、紫外、SEM、DSC、水接触角等方法对所制备的共混材料进行性能表征。结果随着PCL含量的增加,共混材料的断裂伸长率先下降后上升,拉伸强度逐渐上升,PCL质量分数为100%时共混材料的拉伸强度较未添加提高了104%,对紫外光的屏蔽作用增强,接触角从78.2°下降到53.3°;DSC显示当淀粉的比例相对较大时,整个体系的结晶度较低,但PCL的结晶速率加快。TiO₂的加入未使体系发生化学变化,对共混材料的拉伸强度无明显影响,断裂伸长率先增加后减小,在TiO₂质量分数为0.9%时,达到最大为51.69%。TiO₂...     

纳米纤维素/壳聚糖复合膜的制备和性能

目的获得力学性能和阻隔性能优异的食品包装用壳聚糖膜。方法通过超声法由糠醛渣纤维素制备纳米纤维素(NCC),将其与壳聚糖(CS)共混流延制备纳米纤维素/壳聚糖复合膜(NCC-CS)。结果复合膜中NCC质量分数为5%时,NCC-CS的拉伸强度比纯CS膜提高了30%,NCC-CS的透湿量比纯CS膜降低了24%。SEM分析结果表明NCC-CS复合膜微观结构致密。FT-IR和XRD的分析结果表明CS与NCC间存在着较强的相互作用。结论 NCC的加入对CS膜的力学性能和阻隔性能的提高有促进作用。     

PCL / 纸板复合膜的包装特性及回收工艺研究

为了提高纸板的力学性能和水蒸气阻隔性,采用热压法制备了聚己内酯(PCL)/纸板双层复合膜。分别使用质构仪、动态力学分析仪、透湿仪对材料的力学性能、动态热力学性能以及阻隔性能进行了评价,并对PCL的热封性能和纸板的回收工艺进行了评估。研究表明,与PCL复合后,纸板的拉伸强度提高了约3倍,弹性模量提高了约5倍,阻湿性也显著提高;PCL的复合量和热封温度对材料的热封强度影响较大;纸板回收速度快,平均回收率可达到99%。     

Effects of glycerol and sorbitol on optical,mechanical, and gas barrier properties of potato peel‐based films

Potato peel is a by‐product of potato‐based food production and seen as a zero‐ or negative‐value waste of which millions of tons are produced every year. Previous studies showed that potato peel is a potential material for film development when plasticized with 10% to 50% glycerol (w/w potato peel). To further investigate potato peel as a film‐forming material, potato peel‐based films containing the plasticizer sorbitol were prepared and investigated on their physicochemical properties in addition to films containing glycerol. Due to sufficient producibility and handling of casted films in preliminary trials, potato peel‐based films containing 50%, 60%, or 70% glycerol (w/w potato peel) and films containing 90%, 100%, or 110% sorbitol (w/w potato peel) were prepared in this study. Generally, with increasing plasticizer concentration, water vapor and oxygen permeability of the films increased. Films containing glycerol showed higher water vapor and oxygen permeabilities than films containing sorbitol. Young's modulus, tensile strength, and elongation at break decreased with increasing sorbitol concentration, whereas no significant effect of plasticizer content on elongation at break was shown in films containing glycerol. Due to crystallization of films containing sorbitol as a plasticizer, potato peel‐based films containing 50% glycerol (w/w) were identified as the most promising films, characterized by a water vapor transmission rate of 268 g 100 μm m^?2 d^?1 and an oxygen permeability of 4 cm³ 100 μm m^?2 d^?1 bar^?1. Therefore, potato peel‐based cast films in this study showed comparable tensile properties with those of potato starch‐based films, comparable water vapor barrier with those of whey protein‐based films, and comparable oxygen barrier with those of polyamide films.     

PBAT/ZSM-5分子筛共混薄膜的制备与性能

目的 以聚己二酸-对苯二甲酸丁二酯(PBAT)为基材,制备PBAT/ZSM-5分子筛共混薄膜,研究分子筛含量对薄膜性能的影响.方法 通过共混熔融挤出流延法制得含不同质量分数ZSM-5分子筛(0％,1％,3％,5％,7％)的PBAT薄膜,测定分析不同分子筛质量分数对薄膜的颜色、透明性、结构、气体阻隔性、力学性能等性能的影响.结果 随着分子筛质量分数的增加,透明性和断裂伸长率显著降低,抗拉强度先增加后降低,质量分数为1％分子筛的薄膜抗拉强度相对较大,较纯PBAT薄膜增加了12.34％;薄膜氧气透过性能整体上呈上升趋势,二氧化碳透过性和CO2/O2透过比均逐渐增加,水蒸气透过性显著降低,与纯PBAT薄膜相比,质量分数为7％分子筛PBAT薄膜的氧气和二氧化碳透过系数分别增加了18.48％,33.51％,水蒸气透过系数下降了43.28％,CO2/O2透过比由原来的8.84增加到9.96;薄膜表面和横截断面均变得粗糙,局部区域有团聚现象,且随分子筛含量的增加而变得明显.结论 ZSM-5分子筛的少量加入,可以影响PBAT薄膜力学性能,降低其水蒸气透过性,调节薄膜的气体选择透过性,为其应用于生鲜果蔬包装提供基础.     

茶多酚对壳聚糖/聚乙烯醇复合膜性能的影响

目的以茶多酚为改性剂对壳聚糖/聚乙烯醇复合膜进行共混改性,制备一种综合性能良好的绿色包装材料。方法采用溶液共混法制备不同茶多酚质量分数的壳聚糖/聚乙烯醇复合膜,并对其进行红外光谱分析,以及力学性能、水溶性、气体阻隔性、抗氧化性能的测试。结果茶多酚与壳聚糖/聚乙烯醇基质间发生了分子间相互作用,当茶多酚的质量分数为2%时复合膜的综合性能最好,拉伸强度提高了4.99%,且可保持较高的断裂伸长率,水溶性、水蒸气透过率和氧气透过率分别降低了82.43%,51.40%和72.77%,抗氧化能力增强了58.54%。结论添加适量的茶多酚能够提高壳聚糖/聚乙烯醇复合膜的力学性能和耐水性,并改善其气体阻隔性和抗氧化性能。     

Processing and properties of poly(ε-caprolactone)/carbon nanofibre composite mats and films obtained by electrospinning and solvent casting

Composite materials based on poly(ε-caprolactone) (PCL) and carbon nanofibres (CNFs) were processed by solvent casting and electrospinning. The main objective was to investigate the effects of the CNFs on the microstructural, thermal and mechanical properties of the PCL matrix composites processed by two different routes. The hybrid materials obtained with different CNF content (1, 3 and 7 wt%) were analysed by electron microscopy (FESEM), differential scanning calorimeter (DSC), thermogravimetry (TGA) and mechanical testing. The composite films showed a good dispersion in the PCL matrix while electrospun samples were consisted of homogeneous and uniform fibres up to 3 wt% CNFs with average fibre diameter ranged between 0.5 and 1 μm. Composite films and mats revealed an increased crystallization temperature with respect to the neat PCL matrix. Mechanical properties of solvent cast films and electrospun mats were assessed by uniaxial tensile tests. A stiffness increase was achieved in PCL films depending on the CNF content, while mechanical properties of mats were only slightly affected by CNF introduction.     

Manufacture and research of TPS/PE biocomposites properties

In this paper the process of native starch preparing for modification by extrusion and manufacture of biocomposites is presented. The first aim of this study was to determine the mixing and granulating condition of native starch to obtain granulated native starch. For mixing and granulation of native starch Intensive Mixer manufactured by Maschinenfabrik Gustav Eirich was used. Mixing and granulation in a single process is a new method of preparation of powders for other processing. The main task of granulation is the elimination of dust emissions and the increase in density of powders. Granules are easy for dosage and more handy for transport and storage than powders, which is important from a technological point of view.The second aim of this study was to manufacture TPS/PE biocomposites. At first thermal modification of waxy maize starch was carried out with the use of a co-rotating twin screw extruder. During extrusion native starches have been deprived of their crystallinity and the obtained starch (TPS) has fully amorphous structure. XRD analysis revealed that semi crystalline phase of native starch after extrusion disappeared. During extrusion crystal structure of native starch is transformed into amorphous structure of thermoplastic starch (TPS), which was confirmed by XRD analysis.Reactive extrusion of obtained thermoplastic starch and high density polyethylene (HDPE) in the presence of polyethylene-grafted maleic anhydride (PE-g-MA) was done. To modify properties of TPS/PE blend polycaprolactone (PCL) was added in amount of 5 and 10 wt.%. The mass flow rate, static mechanical properties, thermal properties and morphology of obtained biocomposites were examined. The results show that the increased amount of TPS caused an increase in tensile strength and modulus of elasticity of prepared biocomposites. Addition of PCL to TPS/PE blends decreased tensile strength and modulus of elasticity. Moreover, higher amount of TPS and PCL in TPS/PE blends caused decrease of the elongation at break. On the other hand, using of PE-g-MA in TPS/PE blends cause increasing phase compatibility, which was confirmed by mechanical properties and morphology measurements.Biocomposites filled with higher TPS content (45 and 60 wt.%) possess lower resistance to hydrolytic degradation, which cause decrease of mechanical properties.It was found that higher amount of TPS in TPS/PE blends have small effect on mass flow rate and thermal properties estimated by differential scanning calorimetry (i.e. melting temperature, degree of crystallinity, melting enthalpy). This phenomenon have significant influence on processing of obtained biocomposites.