Teaching and Evaluating LLMs to Reason About Polymer Design Related Tasks
Dikshya Mohanty, Mohammad Saqib Hasan, Syed Mostofa Monsur, Size Zheng, Benjamin Hsiao, Niranjan Balasubramanian
TL;DR
This work introduces PolyBench, a large-scale, ground-truth benchmark (over $125k$ polymer-design tasks drawn from $13$M+ data points) to study LLM-based reasoning in polymer design. It combines a knowledge-augmented distillation pipeline with six task categories to teach models structural understanding, property inference, and synthesis planning, while providing explicit chain-of-thought traces grounded in rich polymer data. Experiments show that small LLMs finetuned on PolyBench outperform comparable baselines and even some frontier models on the PolyBench test set, and generalize to external polymer benchmarks. The results reveal a compositionality gap in current models and demonstrate that targeted domain alignment and reasoning traces significantly improve polymer-design capabilities, with substantial implications for AI-assisted polymer discovery and design.
Abstract
Research in AI4Science has shown promise in many science applications, including polymer design. However, current LLMs prove ineffective on this problem space because: (i) most models lack polymer-specific knowledge (ii) existing aligned models lack coverage of knowledge and capabilities relevant to polymer design. Addressing this, we introduce PolyBench, a large scale training and test benchmark dataset of more than 125K polymer design related tasks, leveraging a knowledge base of 13M+ data points obtained from experimental and synthetic sources to ensure broad coverage of polymers and their properties. For effective alignment using PolyBench, we introduce a knowledge-augmented reasoning distillation method that augments this dataset with structured CoT. Furthermore, tasks in PolyBench are organized from simple to complex analytical reasoning problems, enabling generalization tests and diagnostic probes across the problem space. Experiments show that small language models (SLMs), of 7B to 14B parameters, trained on PolyBench data outperform similar sized models, and even closed source frontier LLMs on PolyBench test dataset while demonstrating gains on other polymer benchmarks as well.
