To enhance a viscosity of poly(butylene succinate) (PBS), a crosslinking agent (i.e. dicumyl peroxide, DCP) or branching agent (i.e. Desmodur®N3300, N3300) was incorporated with various amount ranging from 0 to 4 phr via an internal mixer. The thermal transition, rheological properties (e.g. storage modulus, loss modulus, and complex viscosity) and gel content of the compound were determined via differential scanning calorimeter, rheometer, and gel content measurement, respectively. The results revealed that less degree of crystallinity, higher viscosity and more crosslinked structure were detected as increasing amount of DCP and N3300. Subsequently, a compression moulding technique was used to prepare PBS foam with a chemical blowing agent, i.e. azodicarbonamide (ADC). Scanning Electron Microscopy was acquired to examine cell size, cell size distribution, cell structure, and cell density. Besides, physical properties, e.g. foam density and physical appearance, were investigated. The results indicate that the degree of crystallinity, viscosity, and crosslinked structure affect the morphological and physical properties of PBS foams, i.e. greater viscosity and crosslinked structure causing obstacle for cell growth, and less degree of crystallinity allowing easier cell nucleation and cell growth.

中文翻译：

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交联剂和支化剂对聚丁二酸丁二醇酯泡沫形态和物理性质的影响

为了提高聚丁二酸丁二醇酯 (PBS) 的粘度，通过密炼机以 0 至 4 phr 的各种量加入交联剂（即过氧化二异丙苯，DCP）或支化剂（即 Desmodur®N3300、N3300） . 该化合物的热转变、流变特性（例如储能模量、损耗模量和复数粘度）和凝胶含量分别通过差示扫描量热仪、流变仪和凝胶含量测量来确定。结果表明，随着 DCP 和 N3300 量的增加，检测到较低的结晶度、较高的粘度和更多的交联结构。随后，使用压缩成型技术制备具有化学发泡剂，即偶氮二甲酰胺 (ADC) 的 PBS 泡沫。获得扫描电子显微镜检查细胞大小，细胞大小分布、细胞结构和细胞密度。此外，还研究了物理特性，例如泡沫密度和物理外观。结果表明，结晶度、粘度和交联结构影响PBS泡沫的形态和物理性质，即较大的粘度和交联结构会阻碍细胞生长，而较低的结晶度使细胞更容易成核和细胞生长。