摘要
发展可再生、可降解脂肪族热塑性弹性体有望部分替代目前广泛使用的聚苯乙烯型热塑性弹性体材料,对于解决塑料污染问题具有重要意义.本工作以商品化的生物基单体δ-己内酯和L-丙交酯为原料,利用有机碱(t-BuP_(2))/脲二元催化体系实现其顺序开环聚合,成功制备得到聚乳酸-b-聚(δ-己内酯)-b-聚乳酸三嵌段共聚物.这些三嵌段共聚物随软硬段比例不同表现出不同的力学性质.在硬段体积分数较高时(0.30<f_(hard)<0.45),三嵌段共聚物表现出热塑性弹性体性质,具有较高的断裂伸长率和弹性回复率.在硬段体积分数较小时(f_(hard)<0.22),三嵌段共聚物与环氧大豆油混合后可作为压敏胶使用.
It is of significance to develop renewable and biodegradable aliphatic thermoplastic elastomers,which are promising replacement of the widely used polystyrene-based thermoplastic elastomer materials and are expected to partially address the end-of-life issue of plastics.Poly(lactic acid)-b-poly(δ-caprolactone)-b-poly(lactic acid)triblock copolymer was successfully prepared by sequential ring-opening copolymerization of commercial bio-basedδ-caprolactone and L-lactide in the presence of an organobase(t-BuP_(2))/urea as binary catalytic system.These triblock copolymers exhibited different microphase separation structures and mechanical properties depending on the composition of soft and hard segments.As the volume fraction of the hard segment(f_(hard))increased from 0.22 to 0.34,the microphase separation structure of the sample gradually changed from spheres to hexagonally packed cylinders,and finally to lamella.When f_(hard)was in the range of 0.30-0.45,the triblock copolymers behaved as thermoplastic elastomers(TPEs)with high elongation at break(ε_b=600%-1000%)and good tensile strength(σ_(b)=10-20 MPa).The samples with f_(hard)~0.35 exhibited high elastic recovery(E_R~90%),high resilience(~70%)and low residual strain(<10%).When the samples possessed comparable molecular weight of soft segment,the elastic recovery and resilience gradually decreased while the residual strain increased as f_(hard)decreased from 0.34 to 0.22.The triblock copolymers that possessed a relatively lower volume fraction of the hard segment(f_(hard)<0.22)can be used as pressure-sensitive adhesives after mixing with epoxy soybean oil(ESO).The 180°peel strength of PSA can be further adjusted by changing the composing triblock copolymers and the ratio of copolymers to ESO.The 180°peel adhesion tests showed that the peel strength of PSA-1 was(3.0±0.4)N/cm,and that of PSA-2was(0.3±0.05)N/cm,which can be used as kraft paper tape and post-it note,respectively.
作者
王丽颖
沈勇
李志波
Li-ying Wang;Yong Shen;Zhi-bo Li(State Key Laboratory Base of Eco-Chemical Engineering,College of Chemical Engineering;Key Laboratory of Biobased Polymer Materials,Shandong Provincial Education Department,College of Polymer Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042)
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2024年第5期582-593,共12页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号22075160,52322304,22031005)
山东省泰山学者计划(项目号tsqn202103078)资助。
关键词
热塑性弹性体
压敏胶
三嵌段共聚物
开环聚合
脂肪族聚酯
Thermoplastic elastomers
Pressure-sensitive adhesives
Triblock copolymer
Ring-opening polymerization
Aliphatic polyester
