Study On The Hydrolysis Law And Aging Properties Of Polybutylene Succinate (PBS) Blend

Polybutylene succinate（PBS）is a degradable plastic with good comprehensive properties,which is widely used in many fields.However,due to the poor hydrophilicity of PBS,the hydrolysis reaction can only occur on the surface of PBS products,so the hydrolysis speed of products with large thickness is very slow.At present,there are few studies on the modification of PBS to promote hydrolysis,so it is of great significance to study the PBS that can be hydrolyzed quickly.It is a simple,effective and economical method to adjust the hydrolysis rate by adding alkaline filler and water guide agent to PBS.In this paper,PBS/basic filler,PBS/water conducting agent and PBS/basic filler/water conducting agent blends were prepared by melt blending method.The mechanical properties and hydrolysis properties of the blends were tested,and the formula with the best hydrolysis effect was selected.It is found that for PBS/alkaline filler system,calcium oxide（Ca O）can promote the hydrolysis of PBS compared with strontium oxide（Sr O）and magnesium oxide（Mg O）.The degree of hydrolysis of the blends is positively correlated with the amount of Ca O,but the mechanical properties become worse.For PBS/water conducting agent system,sodium polyacrylate（PAAS）can make PBS lose a certain weight after hydrolysis compared with polyethylene glycol 6000 distearate（PEG）and diatomite,but the degree of hydrolysis is low and the mechanical properties become worse.For the PBS/alkaline filler/water conducting agent ternary system,the water conducting agent was added on the basis of adding 20 parts of Ca O.It was found that the effect of promoting hydrolysis was the best after adding peg,which could be completely dissolved within 12 hours,and the lower the molecular weight of PEG,the better the promotion effect.The sample added with PAAS can be dissolved within 18 h,and both can promote the hydrolysis of PBS in synergy with Ca OThe properties of PBS/PEG blends before and after hydrolysis were studied.The results show that for PBS/Ca O-20 system,the more peg is added in the same hydrolysis environment,the better the hydrolysis performance is.After PEG is dissolved in water,more water channels can be formed to induce water molecules to enter PBS and accelerate ester hydrolysis;Ca O can be used as a nucleating agent to provide PBS with a large number of nucleation sites to promote its crystallization.In the middle stage of hydrolysis,some Ca O is dissolved,and the reduction of nucleation sites leads to the difficulty of PBS crystallization.In the later stage of hydrolysis,Ca O and PEG have been dissolved out of the matrix,and the degradation form of PBS is transformed from surface degradation to bulk degradation;XRD curves showed that hydrolysis did not change the crystal form of PBS;Infrared analysis confirmed that the hydrolysis of PBS was due to the fracture of a large number of ester groups.In addition,compared with pure PBS,the mechanical properties of processed PBS/Ca O/PEG ternary materials become worse.To solve this problem,the comprehensive properties of the blends in the process of thermal aging are deeply analyzed in this paper.It was found that pure PBS did not degrade after heat treatment at90℃for 12 hours,and its mechanical properties were improved due to the further improvement of crystal growth during annealing;For PBS/Ca O-20 blends,the mechanical properties were improved after heat treatment,but a small amount of molecular chains on the surface of PBS were hydrolyzed and broken due to Ca（OH）₂alkaline environment formed by Ca O water absorption during sample preparation;For PBS/PEG-10 system,the mechanical properties decreased significantly after heat treatment.The main reason is that peg is degraded by thermal oxygen,and the generated free radicals break the molecular chain of PBS,which leads to the decrease of molecular weight and poor mechanical properties of PBS;For the PBS/Ca O-20/PEG-10 ternary blend system,the mechanical properties decreased more obviously after thermal aging.The PBS main chain degraded greatly under the joint action of Ca O and PEG,and the hydrolysis rate of the sample slowed down with the extension of aging time.This paper mainly studies the hydrolysis law and aging properties of PBS.This work provides guidance for the material selection and process design of soluble temporary plugging agent,and hopes to expand the application range of PBS based degradable plastics.