摘要
黏性食品易在包装材料表面残留,影响消费者体验的同时不利于材料的循环利用。文中结合化学合成、物理共混和压痕制备了聚(L-乳酸)(PLLA)基超疏水酸奶包装膜,并考察了酸奶在其表面的残留情况。首先以疏水端羟基聚二甲基硅氧烷(PDMS)为引发剂,采用开环聚合制备了柔性疏水三嵌段共聚物PLLA-PDMS-PLLA(PLDL)。进一步混入纳米疏水二氧化硅(SiO2)增加材料粗糙度,最后采用不同凸起直径的模板进行热压,构建了不同的表面结构。分析了薄膜热学性能、力学性能、氧气透过性能和水蒸气透过性能等包装性能,同时观察了薄膜表面微观结构,测量其接触角的大小。最后,以酸奶为对象,测试了其在不同薄膜表面的残留量。结果表明,共混膜结晶度降低,具有良好的柔韧性,最大断裂伸长率约为纯PLLA的10倍。且PDMS和纳米粒子加入后,薄膜的水蒸气和氧气阻隔性有所提高,利于酸奶的保质。PDMS的引入可以将PLLA的接触角从79°提高至110°。添加0.5%SiO2并经凸起直径为80μm的模板热压后,PLDL0.5Sμ-80的共混薄膜接触角高达153°,显示了超疏水效果,黏度为300 mPa·s的酸奶在改性薄膜表面的黏附残留量降低至9.4%。
Sticky food is prone to residue on the surface of packaging material,affecting the consumer experience while not conducive to the recycling of materials.This research aimed at preparing super-hydrophobic poly(lactic acid)(PLLA)by the combination of copolylization,blending and hot pressing.The PLLA-PDMS-PLLA(PLDLx)triblock copolymer was synthesized by ring-opening polymerization of lactide(LA)with hydroxy-terminated polydimethylsiloxane(PDMS)as initiator.The copolymer was further blended with different contents of nano hydrophobic silica(SiO2)to improve its hydrophobicity.Finally,didderent surface structures were constructed by hot pressing.The structure,composition,molecular weight,mechanical properties,gas barrier property and contact angle of the composite films were characterized.Results show that the composite films keep better flexibility and the maximum elongation at break is increased about 10 times;the water vapor and O2permeability are decreased slightly.Moreover,the contact angle of the PLDL0.5Sμ-80 blending film reaches 153°,suggesting a super-hydrophobicity.The residual rate of yogurt with 300 mPa·s viscosity decreases to only 9.4%.
作者
云雪艳
张茹茹
王洋样
张慧如
董同力嘎
Xueyan Yun;Ruru Zhang;Yangyang Wang;Huiru Zhang;Tungalag Dong(College of Food Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2022年第12期100-109,共10页
Polymer Materials Science & Engineering
基金
国家自然基金青年科学基金项目(21805142)
内蒙古自治区草原英才工程青年创新创业人才培养计划(2020)
内蒙古农业大学青年科技骨干基金项目(2017XQG-4)。
关键词
聚(L-乳酸)
聚二甲基硅氧烷
接触角
超疏水性
酸奶残留
poly(lactic acid)
poly-dimethylsiloxane
contact angle
super-hydrophobicity
residual rate of yogurt
