Kinetic theories of crystallization of polymers do not apply to high supercooling. The thickness of the crystalline lamellae becomes independent of the crystallization temperature and is a characteristic parameter of the polymer. We relate this limiting thickness to the flexibility of the polymer chain ...
K Nakamura,K Katayama,T Amano - 《Journal of Applied Polymer Science》 被引量: 749发表: 1973年 Some aspects of nonisothermal crystallization of polymers. I. Relationship between crystallization temperature, crystallinity, and cooling conditions The changes in temperature and crystallinity of polymer dur...
Hoffman方程:(二次成核时临界核的高度) L TH T L m me 0 2 (2)结晶体的生长速率 若结晶过程为成核控制,则结晶的线生 长速率G与二次成核速率I*成正比 RT G RT E GG d * 0 exp 320340360380400420440460480500520540 -1 0 1 2 3 4 5 6 7 III III G ( m / m i n ) Temperature(K) 结晶...
Crystallization of polymers Another factor that determines a polymer’s physical properties is its morphology, that is the alignment of the polymer chains. These chains fold together, and form ordered regions (plates), which are composed of larger spherical semicrystalline regions inside non-branched l...
Crystallization during polymerization of p-xylylene from the gas phase has been studied between 200 and −196°C. From room temperature to −17°C the polymer crystal morphology changes in that the crystallinity decreases. In this range the process is thought to be of the successive polymerizat...
aMonthly salary of 8500 deduction of personal income tax should be less than 200 yuan. 8500个人所得税的扣除月薪少于200元应该是。[translate] arearing 抚养[translate] aX. Crystallization of polymers is of great technological importance due to the mechanical properties imparted, which ultimately result...
The half time of crystallization (τ1/2) of poly(l-lactic acid), measured in isothermal conditions after cooling from the melt, is reported in Fig. 1 as a function of temperature (Tc). As typical for polymers, crystallization of PLLA is slow in the temperature ranges close to the melting...
The effective confinement on crystallization occurs while the size of lamellae-like confinement goes below submicrometer. Under effective confinement, the crystalline chains of PCL appear in random orientation at low crystallization temperature and in parallel orientation at high crystallization temperature as...
Bulk isothermal crystallization kinetics of some highly tactic 1,4- cis -polybutadienes obtained with a new catalyst based on uranium derivatives were dilatometrically measured over a crystallization temperature ( T c ) range from 30 to 0°C. The corresponding experimental melting temperatures ( T...
Thermodynamics of Crystallization in High Polymers: Natural Rubber1,2 The existence of an equilibrium melting temperature, T0m, at 28±1°, for unstretched natural rubber has been established, using dilatometric methods. The lower melting temperatures previously observed are a consequence of the low...