Cellulose diacetate (CDA) can be melt-processed to produce numerous and widely-used plastic products. However, due to the high glass transition temperature (T_g) of CDA, the addition of up to 30 wt% of micromolecular plasticizers is indispensable, which significantly reduces the dimensional stability and raises safety concerns from the migration of plasticizers. In this work, a series of CDA-graft-poly(lactic acid) (CDA-g-PLA) copolymers were synthesized by ring-opening polymerization of lactide onto the hydroxyl groups of CDA. The resultant CDA-g-PLA copolymers possess adjustable degrees of substitution (DS_PLA) and side chain length (DP_PLA) by controlling the reaction time and feed ratio. The T_gs and thermal flow temperatures (T_fs) of CDA-g-PLA strongly depend on DP_PLA, such as the T_gs decrease linearly with the increase of DP_PLA. The CDA-g-PLA copolymers with the DP_PLA of 3–9 can be directly processed to transparent plastics by melt processing without any external plasticizers, because of their low T_fs of 170–215 °C. More impressively, the CDA-g-PLA can act as the macromolecular plasticizer. The obtained CDA/CDA-g-PLA has higher storage modulus, flexural modulus and Young’s modulus than the commercial CDA plasticized with triethyl citrate. In addition, the CDA/CDA-g-PLA exhibits high dimensional stability and anti-migration property. During a long-term treatment at 80 °C and 60% humidity, the CDA/CDA-g-PLA can retain the initial shape. Therefore, this work not only proposes a facile method for achieving a direct thermoplastic processing of CDA, but also provides a macromolecular plasticizer for CDA to make lightweight, stable and safer biobased thermoplastics.

可以对二乙酸纤维素（CDA）进行熔融加工，以生产大量且用途广泛的塑料产品。然而，由于CDA的高玻璃化转变温度（T _g），必须添加高达30wt％的微分子增塑剂，这显着降低了尺寸稳定性并引起了增塑剂迁移的安全性问题。在这项工作中，通过将丙交酯在CDA的羟基上开环聚合，合成了一系列CDA-接枝聚乳酸（CDA- g -PLA）共聚物。通过控制反应时间和进料比，所得的CDA- g- PLA共聚物具有可调节的取代度（DS _PLA）和侧链长度（DP _PLA）。的CDA- g - _PLA的T _g s和热流温度（T _f s）很大程度上取决于DP _PLA，例如T _g s随着DP _PLA的增加呈线性下降。该CDA-克与DP -PLA共聚物_PLA的3-9可直接加工到透明塑料通过熔融加工，无需任何外部增塑剂，因为其低Ť _˚F的170-215℃，秒。更令人印象深刻的是，CDA- g -PLA可以充当高分子增塑剂。获得的CDA / CDA- g-PLA比用柠檬酸三乙酯增塑的市售CDA具有更高的储能模量，弯曲模量和杨氏模量。另外，CDA / CDA- g- PLA表现出高的尺寸稳定性和抗迁移性能。在80°C和60％湿度的长期治疗过程中，CDA / CDA- g -PLA可以保持初始形状。因此，这项工作不仅提出了一种用于直接进行CDA热塑性塑料加工的简便方法，而且提供了一种用于CDA的大分子增塑剂，以制造轻质，稳定和安全的生物基热塑性塑料。