影响纤维素包装膜阻隔性能的溶浆工艺参数模型研究

以聚合度为1067的阔叶浆粕为原料,采角LiCl／DMAc为溶剂,利用流延刮膜法制备具有一定透氧透湿性能的纤维素包装膜;通过均匀设计建立制膜的溶解工艺参数与纤维素膜透氧透湿系数的数学模型,并对其进行显著性验证,研究溶浆工艺对纤维素包装膜阻隔性能的影响;实验结果表明：随着活化时间的延长和溶解温度的升高,纤维素包装膜的透氧透湿系数、透氧透湿能力先降低后增大;静置时间的延长将引起纤维素膜的透氧透湿系数降低;回归方程计算得到溶解条件对纤维素膜透氧透湿性能影响呈二次关联。     

微纤化纤维素/聚乳酸薄膜的制备及性能分析

目的将微纤化纤维素(MFC)和聚乳酸(PLA)共混成膜,以提高薄膜的透湿、透氧、阻光等性能,满足果蔬等食品的包装要求。方法采用酶解法与机械处理的方法制备MFC,使用硅烷偶联剂KH560对MFC进行疏水改性处理,再将改性处理的微纤化纤维素(MFC-S)与PLA共混制成薄膜。结果当MFC-S的质量分数为0.75%时,MFC-S/PLA共混包装膜的拉伸强度比纯PLA膜增加了13.3%,当MFC-S的质量分数为2%时,MFC-S/PLA共混包装膜的透氧系数为纯PLA膜的1.43倍,透湿系数为纯PLA膜的1.26倍,透光率降低了60%,阻光效果较好。结论 MFC-S的质量分数为0.75%时,包装膜的拉伸强度较好;MFC-S的质量分数为2%时,透氧、透湿、阻光性较好。     

聚乳酸单轴拉伸膜的包装特性研究

目的研究了不同拉伸比的PLLA薄膜的热学性能、阻隔性能和热收缩性能。方法采用双螺杆挤流延试验机单轴拉伸制备了不同拉伸比的PLLA热收缩膜和定向拉伸膜,采用差示扫描量热分析仪(DSC)、透湿仪和透氧仪对不同拉伸比的PLLA薄膜的热学性能和阻隔性能进行了评估,并对PLLA膜的热收缩性进行了测定。结果热收缩膜的拉伸比由1增大到6.5时,PLLA的结晶度由0.2%增加到41.8%,结晶速率明显提高,阻隔性得到了一定的改善。随着拉伸比例的增大,热收缩率随之增大。定向拉伸膜的结晶度得到了大幅度提高,其阻隔性也得到了改善,但不呈现热收缩性。结论通过单轴拉伸可以有效地提高PLLA薄膜的结晶速率和结晶度,经过中等拉伸比例的PLLA薄膜,其阻湿阻氧能力相对较强。     

甘油对中试魔芋葡甘聚糖流延膜性能的影响

目的解决可食性魔芋葡甘聚糖膜在连续化生产过程中出现的皱缩、易破损的问题。方法向魔芋葡甘聚糖料液中添加一定量的甘油,改善其平整度、柔韧性、拉伸性。结果当甘油添加量达到魔芋葡甘聚糖质量的25%时,制备出了皱缩率最低达0和断裂伸长率最高达65%的薄膜,该膜具有平整、透明度高以及拉伸性能好的特性。结论随着甘油添加量的增加,膜的皱缩率和拉伸强度降低;膜厚度、透明性、断裂伸长率和透湿系数增大。     

纤维素 / 聚碳酸亚丙酯多元醇共混膜的包装性能研究

用溶液铸膜工艺制备了纤维素 / 聚碳酸亚丙酯多元醇共混膜,以扫描电子显微镜、电子拉力机、差示量热扫描仪、透气透湿仪等试验仪器对共混膜进行了表征和性能测试。 研究表明:纤维素 / 聚碳酸亚丙酯多元醇共混膜的力学性能和透湿性能随聚碳酸亚丙酯多元醇含量的提高而提高,而透气性能则相反。 共混膜中聚碳酸亚丙酯多元醇含量为 30% 时共混膜的力学性能最好,共混膜中聚碳酸亚丙酯多元醇含量为 40% 时透湿性能最好,透气性能最差。     

硬脂酸改性小麦醇溶蛋白膜的制备与性能研究

以硬脂酸为改性剂、甘油为增塑剂,分别采用溶液浇铸法、高温模压法制备了小麦醇溶蛋白膜,考察了硬脂酸改性对醇溶蛋白膜力学性能、动态力学性能及吸水与透湿性能的影响.结果表明,模压膜的性能明显优于浇铸膜.随硬脂酸含量增大,模压膜弹性模量增大,吸水率略有降低,而透湿率明显降低.模压膜呈现相分离结构,硬脂酸改性可降低蛋白质富集相的非均质程度,并使甘油富集相的玻璃化转变温度向高温移动.     

打坑BOPP薄膜的透湿性能研究

打坑薄膜通过对薄膜进行打坑微处理,可提高其透氧性能及透湿性能。打坑BOPP薄膜在食品包装中得到了广泛的应用,但使用过程中其透湿性不好的问题较为突出,包装内易出现结露问题。以透湿性能为试验指标,选用2种不同透氧系数的打坑BOPP薄膜和未打坑BOPP薄膜进行了对比试验。结果表明,透氧系数大的打坑BOPP薄膜的透湿量也相对较大;同时,透氧系数相同的打坑BOPP薄膜的反面透湿量要大于其正面透湿量;对于不同透氧系数规格的薄膜,反面的透湿性增加量要大于正面的。可见,在实际应用中,不仅需要根据透氧系数来选择合适的包装用BOPP薄膜,且在应用时还需调整薄膜正反面的选择。     

PLA和PE包装袋对西兰花贮藏品质的影响

目的考察聚乳酸(PLA)与聚乙烯(PE)袋对西兰花贮藏品质的影响。方法利用透氧仪和透湿仪对市售的PLA和PE膜进行阻隔性测试,并采用该PLA和PE袋包装西兰花,利用色度计和顶空分析仪研究室温和冷藏条件下2种包装袋对西兰花保鲜效果的影响。结果 PLA膜的透湿系数和透氧系数分别为1.241×10-13 g·cm/(cm2·s·Pa)和5.07×10-10 m L·cm/(m2·s·Pa),PE膜的透湿系数和透氧系数分别为1.125×10-14 g·cm/(cm2·s·Pa)和2.87×10-10 m L·cm/(m2·s·Pa)。随着贮藏时间的延长,西兰花的色度由绿变红,由蓝变黄,明度由黑变白;袋中O2气氛浓度先减少后增加,CO2浓度先上升后下降。结论 PLA膜的透湿性和透氧性高于PE膜,冷藏条件下,PLA比PE袋能更有效地抑制西兰花的呼吸作用。     

微波处理对塑料薄膜包装材料阻隔性能影响的研究

研究了常用的塑料薄膜包装材料经微波处理不同时间后其透氧率、透湿率的变化规律.研究结果表明,塑料单膜随微波处理时间增加,透氧率明显增大,而复合薄膜透氧率变化较小;透湿率变化正好相反,微波处理相同时间后,复合薄膜透湿率增长明显大于塑料单膜.     

聚乳酸/茶多酚抗氧化膜的制备及其性能研究

以聚乳酸（PLA）为基材,茶多酚（TP）为抗氧化剂,通过流延法制备了具抗氧化活性的可降解PLA/TP共混膜,并研究了茶多酚添加量对共混膜包装性能及抗氧化性能的影响。研究结果表明：茶多酚与聚乳酸基质间发生了相互作用,茶多酚在聚乳酸基质中具有较好的分散性。天然抗氧化物茶多酚的添加使共混膜的拉伸强度、断裂伸长率以及透光率降低,但显著提高了共混膜的热封强度、透湿系数、透氧系数、溶解度和自由基清除率。当茶多酚的质量分数为0.9%时,共混膜的热封强度为3.31 N/(15 mm),透湿系数和透氧系数分别是纯PLA膜的1.68倍和6倍,透光率为88.1%,自由基清除率为89.18%,是一种具有应用潜力的环境友好型食品活性包装材料。     

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.     

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%。     

脂质-CMC可食性复合膜阻湿性能的影响因素研究

利用羧甲基纤维素(CMC)为主要成膜材料,添加脂类物质及增塑剂,研究了脂质-CMC可食性复合膜阻湿性能的影响因素。影响膜的阻湿性能的因素依次为:蜂蜡CMC硬脂酸PEG400水/乙醇体积比。随着蜂蜡、硬脂酸含量的增加,可食性膜的水蒸气透过率下降,且2种添加剂均会降低膜的机械性能和阻油性,提高其阻氧性;随着CMC、乙醇、PEG400的含量的增加,膜的水蒸气透过率先下降后上升。结果表明具有较好阻湿性能包装膜的最佳配比为:水/乙醇体积比为95∶5,硬脂酸质量浓度为0.02g/mL,PEG400质量分数为1.5%,蜂蜡质量浓度为0.004g/mL,CMC质量质量浓度为0.03g/mL。     

Physical, antibacterial and antioxidant properties of chitosan films incorporated with thyme oil for potential wound healing applications

Chitosan films incorporated with thyme oil for potential applications of wound dressing were successfully prepared by solvent casting method. The water vapor permeability, oxygen transmission rate, and mechanical properties of the films were determined. Surface and cross-section morphologies and the film thicknesses were determined by Scanning Electron Microscopy (SEM). Fourier transform infrared (FT-IR) spectroscopy was conducted to determine functional group interactions between the chitosan and thyme oil. Thermal behaviors of the films were analyzed by Thermal Gravimetry (TGA) and Differential Scanning Calorimetry (DSC). In addition, the antimicrobial and the antioxidant activities of the films were investigated. The antimicrobial test was carried by agar diffusion method and the growth inhibition effects of the films including different amount of thyme oil were tested on the gram negative microorganisms of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and a gram positive microorganism of Staphylococcus aureus. The minimum thyme oil concentration in chitosan films showing the antimicrobial activity on all microorganisms used in the study was found as 1.2 % (v/v). In addition, this concentration showed the highest antioxidant activity due to mainly the carvacrol in thyme oil. Water vapor permeability and oxygen transmission rate of the films slightly increased, however, mechanical properties decreased with thyme oil incorporation. The results revealed that the thyme oil has a good potential to be incorporated into chitosan to make antibacterial and permeable films for wound healing applications.     

改性二氧化硅对SiO2/PLA复合膜性能的影响

目的研究改性二氧化硅对聚乳酸力学性能、氧气透过性能和水蒸气透过性能的影响。方法选择粒径为50nm的工业级二氧化硅为添加剂,使用KH570硅烷偶联剂对其进行改性,然后通过溶液浇铸法将改性后的二氧化硅与聚乳酸共混制备成膜。测试分析拉伸性能、透氧性能和透水蒸气性能,表征复合膜的力学性和阻隔性能。结果与纯PLA膜相比,改性复合膜的拉伸强度和弹性模量分别提高了18.65%和19.91%;玻璃化转变温度比纯PLA膜高11℃左右,热稳定性得到增强。与纯PLA膜相比,改性复合膜的氧气透过系数和水蒸气透过系数分别降低了29.89%和43.76%,阻隔性明显提高。结论经KH570硅烷偶联剂改性的二氧化硅对聚乳酸材料性能的增强效果更佳,为聚乳酸材料在包装领域的应用提供了依据。     

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.     

姜渣-玉米淀粉膜的制备及研究

目的 制备一种纯天然的、具有抑菌性的可食用淀粉膜。方法 以玉米淀粉为原料,通过添加适量的姜渣、甘油、羧甲基纤维素钠,采用流延法制备姜渣-玉米淀粉膜。结果 当淀粉的质量分数为3%,甘油的质量分数为1%,姜渣的质量分数为0.4%时,膜的透光性、透油性、水蒸气透过性、溶解度、溶胀度等各项指标的综合测定结果较好。生姜中含有姜辣素、姜油等活性成分,添加姜渣可作为天然的抑菌剂,微生物试验结果证实,姜渣-玉米淀粉膜对霉菌和酵母菌具有一定抑菌作用,且抑菌效果与姜渣的含量成正比关系。结论 所制备姜渣-玉米淀粉的结构紧密、光滑平整,并具有一定的抑菌性。     

Permeation of piroxicam from the poloxamer gels

Topical formulations of piroxicam were prepared using poloxamer 407 or poloxamer 188 by a cold method, and the permeation characteristics of piroxicam were evaluated. The permeation rate of piroxicam across the synthetic cellulose membrane and the rat skin decreased as the concentration of poloxamer increased. Though poloxamer gel exhibits reversed thermal behavior, the permeation rate of piroxicam increased with increasing temperature, indicating that the diffusional pathway of piroxicam is a water channel within the gel formulation. The pH of the gel did not affect the permeation rate of piroxicam significantly. As the concentration of piroxicam in the gel formulation increased, the permeation rate of piroxicam increased up to 1% and reached a plateau above 1%. Among various enhancers tested, polyoxyethylene-2-oleyl ether showed the highest enhancing effect, with an enhancement ratio of 2.84. Based on experimental results, the permeation rate of piroxicam can be controlled by changing the poloxamer concentration or drug concentration and by the addition of an appropriate enhancer.     

普鲁兰多糖-明胶可食膜的制备与性能研究

研究了普鲁兰和甘油用量对可食膜的拉伸性能、光学性能和阻隔性能的影响。结果表明,普鲁兰的添加对复合膜的延展性、阻气性、透光率和抗拉强度有显著提高,当添加量超过50%时,复合膜的阻水性和抗拉强度下降明显;甘油的添加可明显提高复合膜的延展性和透光率,同时降低了复合膜的阻水性,当添加量为20%时,复合膜的综合性能较好。