Makromolekulare Chemie

Entropy driven chain effects on ligation chemistry

“… 34 , 57 Of course, T g values are characteristics for polymer melts and cannot be transferred directly to behavior in solution where interactions between polymer and solvent are essential. 58 In addition, the chain length dependence of T g is neglected, as only the relative differences of chains with the same amount of repeating units are of interest in the current study. 59 However, if equal polymer backbones of equal length with different homonuclear side chain substituents are investigated, their T g values should correlate approximately with chain stiffness.…”

Design of natural fiber composites utilizing interfacial crystallinity and affinity

“…(1)with the storage modulus at the rubbery plateau E´, the crosslinking density v e , the gas constant R (8.314 J/(K • mol)), and the temperature T in K. Additionally, the number average molecular weight between crosslinks (M c ) was calculated according to equation 2) considering the densities ρ of the polymers [26,27].…”

“…Covalently linked PCL yielded a significant decrease of the storage moduli (1350 MPa at room temperature for EP/PCL-3) (Figure 1). Based on the storage moduli determined by DMA measurements the crosslinking density v e (mol/m 3 ) was calculated in approximation from the following equation [25,26,27]:…”

Heat generation and distribution in the ultrasonic hot embossing process

“…For decomposition of PVC much less energy is required, and therefore, a useful process window was opened up only when pre-structures where employed in the upper third of the polymer stack. Both polymers are amorphous (Lechner et al 2015). But the glass transition temperature of PVC is only half as high as that of PC.…”

“…But the glass transition temperature of PVC is only half as high as that of PC. Moreover, PVC begins to split off hydrogen chloride at a temperature of 100 °C (Lechner et al 2015). That might be the reason, why for PVC much less energy is sufficient to destroy it.…”