摘要
以粉末 SBR- g- s与 PS树脂共混 ,测定了共混体的 Charpy无缺口冲击强度与 PR用量的关系曲线。用 TEM和 SEM分别分析了共混体的相结构和冲击断面形貌。研究了共混体的相结构、冲击断裂机理和冲击强度之间的关系。结果发现 ,在关系曲线被转变点划分的每一区域内 ,冲击断裂机理只发生量变而无质变 ,故冲击强度与 PR用量成正比 ,而随着区域的变换冲击断裂机理发生了质变 ,导致了冲击强度的变化不连续 ,从而出现转变点。当粉末非交联 SBR- g- s用量为 2 0 % ,共混体发生脆韧转变 ;其冲击断面局部区域呈“须根”形貌 ,证实存在剪切屈服机理 ;脆韧转变的临界条件为 :橡胶相粒径≥ 0 .8μm,粒面间距离≤ 0 .9μm,PS富相含混溶性 SBR( SBR/PS,质量 )≥ 3%。
The SBR g s powder(PR) was blended with PS resin to study the toughening effect of PR on PS. The relationship curve of impact strength of PS/PR blends with PR content were determined. The phase structure and the morphologies of impact fracture surface of the blends were analyzed by means of TEM and SEM, respactively. The relationship between the phase structure, the impact fracture mechanism and the impact strength of the blends was investigated. It was found that the relationship curves are divided into several region by one or more transition points. Within each region, the impact strength is directly proportional to the PR content because the impact fracture mechanism varies only in quantity and does not changed in quality, and the impact fracture mechanism is different in different region leading to the appearance of the transition point where the evolution of impact strength is discontinuous. The blend undergoes tough brittle transition when the non crosslinking SBR g s powder content is 20% by mass and the impact fracture surface shows a root beard morphology confirmed the presence of shear yielding mechanism. The critical conditions of the toughbrittle transition for the blend are as follows: particle diameter of the SBR phase≥0.8 μm, surface to surface inter particle distance≤0.9 μm, SBR contained by the PS rich phase(SBR/PS, by mass)≥3%.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2000年第3期113-117,共5页
Polymer Materials Science & Engineering
基金
国家自然科学基金
关键词
PS
SBR-g-s
共混体
相结构
橡塑共混
PS/SBR g s powder blend
impact strength
impact fracture mechanism
phase structure
shear yielding mechanism
