摘要
以一种苯乙烯-丙烯酸缩水甘油酯共聚物(Joncryl○RADR-4370S)为扩链剂,通过熔融挤出支化改性聚乳酸(PLA),制备了高支化聚乳酸材料,并通过转矩流变仪及毛细管流变仪、GPC、DMA、万能拉伸试验机等研究了不同扩链剂用量对支化改性聚乳酸流变性能、重均相对分子质量及其分布、链结构、动态力学性能和力学性能的影响。结果表明,随着扩链剂含量的增加,支化聚乳酸的平衡扭矩、熔体黏度、重均相对分子质量及其分布(PDI)、拉伸强度、断裂伸长率和缺口冲击强度先增大后减少,储能模量增大,在四氢呋喃溶剂中的链构象由棒状向线团状、球状演变。扩链剂用量为1.5 phr时,支化聚乳酸的平衡扭矩、重均相对分子质量、拉伸强度、断裂伸长率和缺口冲击强度均达到最大值,分别为15.80 N·m,1.96×105,89.6 MPa,7.5%和35.0 k J/m2;扩链剂用量为0.9 phr时,支化聚乳酸的相对分子质量分布最宽,为2.04。
The hyper-branched poly（ lactic acid） was prepared by melting extrusion with styrene-glycidyl acrylate as chain extender（ Joncryl○RADR-4370S）. The rheological properties,molecular weight,molecular weight distribution（ MWD）,chain structure and thermodynamic properties of the hyper-branched poly（ lactic acid） were characterized by the torque rheometer,gel permeation chromatography（ GPC）,dynamic thermomechanical analysis apparatus（ DMA）and universal testing machine. The results show that the balanced torque,melting viscosity,molecular weight,MWD and mechanical properties of the branched PLA increase first,then decrease with the increase of chain extender content,the storage modulus of the branched PLA increases gradually,the chain conformation of branched PLA in tetrahydrofuran solvents evolves from rod-like chain to ball chain. When the content of Joncryl○RADR-4370 S is 1. 5 phr,the balanced torque,the molecular weight,tensile strength,elongation at break and notched impact strength of the branched PLA reach the maximum of 15. 8 N·m,1. 96 × 10^5,89. 6 MPa,7. 5% and 35. 0 k J/m^2 respectively. When the content of the chain extender is 0. 9 phr,the molecular weight distribution of PLA is the widest,which is 2. 04.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2016年第6期79-84,共6页
Polymer Materials Science & Engineering
基金
江苏省产学前瞻项目(BY2012177)
江苏省高校科研成果产业化推进项目(JHB2012-41)
江苏省科技支撑(工业)项目(SBE2014001336)
关键词
聚乳酸
支化改性
扩链剂
分子链构象
polylactide
branching modification
chain extender
chain conformation
