求翻译：本文以聚合松香和季戊四醇为原料，以ZnO，MgO，Ce(SO4)2为催化剂合成聚合松香季戊四醇酯，对聚合松香的酸值和酯化后聚合松香多元醇酯的酸值测定进行研究。探讨了不同催化剂、季戊四醇用量、反应时间对反应结果的影响, 通过测定聚合松香季戊四醇酯的酸值，进而计算酯化率，得到了合成聚合松香多元醇酯的适宜条件。对于聚合松香季戊四醇酯，在催化剂用ZnO（量为0.5025即聚合松香用量的1%）和季戊四醇量为12.5g,时间为7小时的条件下，酯化率最高。是什么意思？

In this paper, polymerized rosin and pentaerythritol as raw materials, ZnO, mgo, ce (so4) 2 for the catalyst polymerized rosin pentaerythritol esters, polymerized rosin acid and esterification and polymerization of the acid value of rosin polyol esters determination study. Explore the different cata

This article in a polymeric resin and E. 4 for alcohol, MgO ZnO, raw materials, to SO Ce 4) ( 2 to act as a catalyst synthetic polymer rosin ester, E. 4 of the polymeric resin acid value and esterification after polyol esters polymeric resin acid value measurement study. explore the different cataly

This polymerized Rosin pentaerythritol and as raw materials, ZnO,MgO,Ce (SO4) 2 catalyst for synthesis of polymerized Rosin