DISTRIBUTION OF HIGHER-ORDER STRUCTURES IN INJECTION-MOLDED POLYPROPYLENES

被引:53
作者
FUJIYAMA, M
WAKINO, T
机构
[1] Polymer Development Laboratory, Tokuyama Soda Co, Ltd., Tokuyama-Shi, Yamaguchi-Ken
关键词
D O I
10.1002/app.1991.070430108
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
Flexural test specimens were injection-molded from six homoisotactic polypropylenes with MFI = 0.49-25.1 dg/min under cylinder temperatures of 200-320-degrees-C. Distributions in the flow direction of higher-order structures such as crystallinity X(c), thickness of skin layer, a*-axis-oriented component fraction [A*], and crystalline orientation functions and distributions in the thickness direction of higher-order structures such as X(c), beta-crystal contents, [A*], and crystalline orientation functions were studied. These higher-order structures are inhomogeneous in the flow and thickness directions, which strongly influences the product properties such as mechanical and thermal properties. Molecular orientation process in injection molding was theoretically analyzed from a viewpoint of growth of recoverable shear strain at the gate and its relaxation in the cavity, which could considerably well explain the variations in the flow and thickness directions of the quantities such as thickness of the skin layer and crystalline orientation functions which express the degree of molecular orientation.
引用
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页码:57 / 81
页数:25
相关论文
共 69 条
[1]  
ALTENDORFER F, 1986, KUNSTST-GER PLAST+, V76, P47
[2]  
ALTENDORFER F, 1984, PLASTVERARBEITER, V35, P144
[3]  
ALTENDORFER F, 1983, PLASTVERARBEITER, V34, P511
[4]  
[Anonymous], 1974, ENTANGLEMENT CONCEPT
[5]   END CORRECTIONS IN THE CAPILLARY FLOW OF POLYETHYLENE [J].
BAGLEY, EB .
JOURNAL OF APPLIED PHYSICS, 1957, 28 (05) :624-627
[6]   HOOKE LAW IN SHEAR AND POLYMER MELT FRACTURE [J].
BAGLEY, EB .
JOURNAL OF APPLIED PHYSICS, 1960, 31 (06) :1126-1127
[7]  
BALLMAN RL, 1960, MOD PLAST, V38, P113
[8]  
CARSLAW HS, 1957, CONDUCTION HEAT SOLI
[9]   CORRELATION OF DYNAMIC AND STEADY FLOW VISCOSITIES [J].
COX, WP ;
MERZ, EH .
JOURNAL OF POLYMER SCIENCE, 1958, 28 (118) :619-622
[10]  
DANUSSO FG, 1959, CHEM IND, V41, P74